resource_manager.go

// Copyright 2018 The Kubeflow Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package resource

import (
	"context"
	"encoding/json"
	"fmt"
	scheduledworkflow "github.com/kubeflow/pipelines/backend/src/crd/pkg/apis/scheduledworkflow/v1beta1"
	"io"
	"net"
	"reflect"
	"strconv"

	"github.com/cenkalti/backoff"
	"github.com/golang/glog"
	"github.com/kubeflow/pipelines/backend/src/apiserver/archive"
	kfpauth "github.com/kubeflow/pipelines/backend/src/apiserver/auth"
	"github.com/kubeflow/pipelines/backend/src/apiserver/client"
	"github.com/kubeflow/pipelines/backend/src/apiserver/common"
	"github.com/kubeflow/pipelines/backend/src/apiserver/list"
	"github.com/kubeflow/pipelines/backend/src/apiserver/model"
	"github.com/kubeflow/pipelines/backend/src/apiserver/storage"
	"github.com/kubeflow/pipelines/backend/src/apiserver/template"
	exec "github.com/kubeflow/pipelines/backend/src/common"
	"github.com/kubeflow/pipelines/backend/src/common/util"
	scheduledworkflowclient "github.com/kubeflow/pipelines/backend/src/crd/pkg/client/clientset/versioned/typed/scheduledworkflow/v1beta1"
	"github.com/pkg/errors"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promauto"
	"google.golang.org/grpc/codes"
	authorizationv1 "k8s.io/api/authorization/v1"
	corev1 "k8s.io/api/core/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	utilerrors "k8s.io/apimachinery/pkg/util/errors"
)

// Metric variables. Please prefix the metric names with resource_manager_.
var (
	extraLabels = []string{
		// display in which Kubeflow namespace the runs were triggered
		"profile",

		// display workflow name
		"workflow",
	}

	// Count the removed workflows due to garbage collection.
	workflowGCCounter = promauto.NewCounter(prometheus.CounterOpts{
		Name: "resource_manager_workflow_gc",
		Help: "The number of gabarage-collected workflows",
	})

	// Count the successfull workflow runs
	workflowSuccessCounter = promauto.NewGaugeVec(prometheus.GaugeOpts{
		Name: "resource_manager_workflow_runs_success",
		Help: "The current number of successfully workflows runs",
	}, extraLabels)

	// Count the failed workflow runs
	workflowFailedCounter = promauto.NewGaugeVec(prometheus.GaugeOpts{
		Name: "resource_manager_workflow_runs_failed",
		Help: "The current number of failed workflows runs",
	}, extraLabels)
)

type ClientManagerInterface interface {
	ExperimentStore() storage.ExperimentStoreInterface
	PipelineStore() storage.PipelineStoreInterface
	JobStore() storage.JobStoreInterface
	RunStore() storage.RunStoreInterface
	TaskStore() storage.TaskStoreInterface
	ResourceReferenceStore() storage.ResourceReferenceStoreInterface
	DBStatusStore() storage.DBStatusStoreInterface
	DefaultExperimentStore() storage.DefaultExperimentStoreInterface
	ObjectStore() storage.ObjectStoreInterface
	ExecClient() util.ExecutionClient
	SwfClient() client.SwfClientInterface
	KubernetesCoreClient() client.KubernetesCoreInterface
	SubjectAccessReviewClient() client.SubjectAccessReviewInterface
	TokenReviewClient() client.TokenReviewInterface
	LogArchive() archive.LogArchiveInterface
	Time() util.TimeInterface
	UUID() util.UUIDGeneratorInterface
	Authenticators() []kfpauth.Authenticator
}

type ResourceManagerOptions struct {
	CollectMetrics bool `json:"collect_metrics,omitempty"`
}

type ResourceManager struct {
	experimentStore           storage.ExperimentStoreInterface
	pipelineStore             storage.PipelineStoreInterface
	jobStore                  storage.JobStoreInterface
	runStore                  storage.RunStoreInterface
	taskStore                 storage.TaskStoreInterface
	resourceReferenceStore    storage.ResourceReferenceStoreInterface
	dBStatusStore             storage.DBStatusStoreInterface
	defaultExperimentStore    storage.DefaultExperimentStoreInterface
	objectStore               storage.ObjectStoreInterface
	execClient                util.ExecutionClient
	swfClient                 client.SwfClientInterface
	k8sCoreClient             client.KubernetesCoreInterface
	subjectAccessReviewClient client.SubjectAccessReviewInterface
	tokenReviewClient         client.TokenReviewInterface
	logArchive                archive.LogArchiveInterface
	time                      util.TimeInterface
	uuid                      util.UUIDGeneratorInterface
	authenticators            []kfpauth.Authenticator
	options                   *ResourceManagerOptions
}

func NewResourceManager(clientManager ClientManagerInterface, options *ResourceManagerOptions) *ResourceManager {
	return &ResourceManager{
		experimentStore:           clientManager.ExperimentStore(),
		pipelineStore:             clientManager.PipelineStore(),
		jobStore:                  clientManager.JobStore(),
		runStore:                  clientManager.RunStore(),
		taskStore:                 clientManager.TaskStore(),
		resourceReferenceStore:    clientManager.ResourceReferenceStore(),
		dBStatusStore:             clientManager.DBStatusStore(),
		defaultExperimentStore:    clientManager.DefaultExperimentStore(),
		objectStore:               clientManager.ObjectStore(),
		execClient:                clientManager.ExecClient(),
		swfClient:                 clientManager.SwfClient(),
		k8sCoreClient:             clientManager.KubernetesCoreClient(),
		subjectAccessReviewClient: clientManager.SubjectAccessReviewClient(),
		tokenReviewClient:         clientManager.TokenReviewClient(),
		logArchive:                clientManager.LogArchive(),
		time:                      clientManager.Time(),
		uuid:                      clientManager.UUID(),
		authenticators:            clientManager.Authenticators(),
		options:                   options,
	}
}

func (r *ResourceManager) getWorkflowClient(namespace string) util.ExecutionInterface {
	return r.execClient.Execution(namespace)
}

func (r *ResourceManager) getScheduledWorkflowClient(namespace string) scheduledworkflowclient.ScheduledWorkflowInterface {
	return r.swfClient.ScheduledWorkflow(namespace)
}

// Creates a new experiment.
func (r *ResourceManager) CreateExperiment(experiment *model.Experiment) (*model.Experiment, error) {
	if common.IsMultiUserMode() {
		if experiment.Namespace == "" {
			return nil, util.NewInvalidInputError("Namespace cannot be empty")
		}
	}
	return r.experimentStore.CreateExperiment(experiment)
}

// Fetches an experiment with the given id.
func (r *ResourceManager) GetExperiment(experimentId string) (*model.Experiment, error) {
	return r.experimentStore.GetExperiment(experimentId)
}

// Fetches experiments with the given filtering and listing options.
func (r *ResourceManager) ListExperiments(filterContext *model.FilterContext, opts *list.Options) ([]*model.Experiment, int, string, error) {
	return r.experimentStore.ListExperiments(filterContext, opts)
}

// Deletes the experiment with the given id.
func (r *ResourceManager) DeleteExperiment(experimentId string) error {
	defaultExperimentId, err := r.GetDefaultExperimentId()
	if err != nil {
		return util.Wrapf(err, "Failed to delete experiment %v due to error fetching the default experiment id", experimentId)
	}
	if defaultExperimentId != "" && experimentId == defaultExperimentId {
		return util.NewBadRequestError(util.NewInvalidInputError("Experiment id cannot be equal to the default id %v", defaultExperimentId), "Failed to delete experiment %v. The default experiment cannot be deleted", experimentId)
	}
	if _, err := r.experimentStore.GetExperiment(experimentId); err != nil {
		return util.Wrapf(err, "Failed to delete experiment %v due to error fetching it", experimentId)
	}
	return r.experimentStore.DeleteExperiment(experimentId)
}

// Archives the experiment with the given id.
func (r *ResourceManager) ArchiveExperiment(ctx context.Context, experimentId string) error {
	// To archive an experiment
	// (1) update our persistent agent to disable CRDs of jobs in experiment
	// (2) update database to
	// (2.1) archive experiments
	// (2.2) archive runs
	// (2.3) disable jobs
	opts, err := list.NewOptions(&model.Job{}, 50, "name", nil)
	if err != nil {
		return util.NewInternalServerError(err,
			"Failed to archive experiment %v", experimentId)
	}
	for {
		jobs, _, newToken, err := r.jobStore.ListJobs(&model.FilterContext{
			ReferenceKey: &model.ReferenceKey{Type: model.ExperimentResourceType, ID: experimentId},
		}, opts)
		if err != nil {
			return util.NewInternalServerError(err,
				"Failed to list jobs of to-be-archived experiment %v", experimentId)
		}
		for _, job := range jobs {
			k8sNamespace := job.Namespace
			if k8sNamespace == "" {
				k8sNamespace = common.GetPodNamespace()
			}
			_, err = r.getScheduledWorkflowClient(k8sNamespace).Patch(
				ctx,
				job.K8SName,
				types.MergePatchType,
				[]byte(fmt.Sprintf(`{"spec":{"enabled":%s}}`, strconv.FormatBool(false))))
			if err != nil {
				return util.NewInternalServerError(err,
					"Failed to disable job %v while archiving experiment %v", job.UUID, experimentId)
			}
		}
		if newToken == "" {
			break
		} else {
			opts, err = list.NewOptionsFromToken(newToken, 50)
			if err != nil {
				return util.NewInternalServerError(err,
					"Failed to create list jobs options from page token when archiving experiment %v", experimentId)
			}
		}
	}
	return r.experimentStore.ArchiveExperiment(experimentId)
}

// Un-archives the experiment with the given id.
func (r *ResourceManager) UnarchiveExperiment(experimentId string) error {
	return r.experimentStore.UnarchiveExperiment(experimentId)
}

// Returns a list of pipelines.
func (r *ResourceManager) ListPipelines(filterContext *model.FilterContext, opts *list.Options) ([]*model.Pipeline, int, string, error) {
	pipelines, total_size, nextPageToken, err := r.pipelineStore.ListPipelines(filterContext, opts)
	if err != nil {
		err = util.Wrapf(err, "Failed to list pipelines with context %v, options %v", filterContext, opts)
	}
	return pipelines, total_size, nextPageToken, err
}

// TODO(gkcalat): consider removing after KFP v2 GA if users are not affected.
// Returns a list of pipelines using LEFT JOIN on SQL query.
// This could be more performant for a large number of pipeline versions.
func (r *ResourceManager) ListPipelinesV1(filterContext *model.FilterContext, opts *list.Options) ([]*model.Pipeline, []*model.PipelineVersion, int, string, error) {
	pipelines, pipelineVersions, total_size, nextPageToken, err := r.pipelineStore.ListPipelinesV1(filterContext, opts)
	if err != nil {
		err = util.Wrapf(err, "ResourceManager (v1beta1): Failed to list pipelines with context %v, options %v", filterContext, opts)
	}
	return pipelines, pipelineVersions, total_size, nextPageToken, err
}

// Returns a pipeline.
func (r *ResourceManager) GetPipeline(pipelineId string) (*model.Pipeline, error) {
	if pipeline, err := r.pipelineStore.GetPipeline(pipelineId); err != nil {
		return nil, util.Wrapf(err, "Failed to get a pipeline with id %v", pipelineId)
	} else {
		return pipeline, nil
	}
}

// Returns a pipeline specified by name and namespace.
func (r *ResourceManager) GetPipelineByNameAndNamespace(name string, namespace string) (*model.Pipeline, error) {
	if pipeline, err := r.pipelineStore.GetPipelineByNameAndNamespace(name, namespace); err != nil {
		return nil, util.Wrapf(err, "Failed to get a pipeline named %v in namespace %v", name, namespace)
	} else {
		return pipeline, nil
	}
}

// TODO(gkcalat): consider removing after KFP v2 GA if users are not affected.
// Returns a pipeline specified by name and namespace using LEFT JOIN on SQL query.
// This could be more performant for a large number of pipeline versions.
func (r *ResourceManager) GetPipelineByNameAndNamespaceV1(name string, namespace string) (*model.Pipeline, *model.PipelineVersion, error) {
	if pipeline, pipelineVersion, err := r.pipelineStore.GetPipelineByNameAndNamespaceV1(name, namespace); err != nil {
		return nil, nil, util.Wrapf(err, "ResourceManager (v1beta1): Failed to get a pipeline named %v in namespace %v", name, namespace)
	} else {
		return pipeline, pipelineVersion, nil
	}
}

// Deletes a pipeline. Does not delete pipeline spec in the object storage.
// Fails if the pipeline has existing pipeline versions.
func (r *ResourceManager) DeletePipeline(pipelineId string) error {
	// Check if pipeline exists
	_, err := r.pipelineStore.GetPipeline(pipelineId)
	if err != nil {
		return util.Wrapf(err, "Failed to delete pipeline with id %v as it was not found", pipelineId)
	}

	// Check if it has no pipeline versions in Ready state
	latestPipelineVersion, err := r.pipelineStore.GetLatestPipelineVersion(pipelineId)
	if latestPipelineVersion != nil {
		return util.NewInvalidInputError("Failed to delete pipeline with id %v as it has existing pipeline versions (e.g. %v)", pipelineId, latestPipelineVersion.UUID)
	} else if err.(*util.UserError).ExternalStatusCode() != codes.NotFound {
		return util.Wrapf(err, "Failed to delete pipeline with id %v as it failed to check existing pipeline versions", pipelineId)
	}

	// Mark pipeline as deleting so it's not visible to user.
	err = r.pipelineStore.UpdatePipelineStatus(pipelineId, model.PipelineDeleting)
	if err != nil {
		return util.Wrapf(err, "Failed to change the status of pipeline id %v to DELETING", pipelineId)
	}

	// Delete a pipeline.
	err = r.pipelineStore.DeletePipeline(pipelineId)
	if err != nil {
		return util.Wrapf(err, "Failed to delete pipeline DB entry for pipeline id %v", pipelineId)
	}
	return nil
}

// TODO(gkcalat): consider removing before v2beta1 GA as default version is deprecated. This requires changes to v1beta1 proto.
// Updates default pipeline version for a given pipeline.
// Supports v1beta1 behavior.
func (r *ResourceManager) UpdatePipelineDefaultVersion(pipelineId string, versionId string) error {
	return r.pipelineStore.UpdatePipelineDefaultVersion(pipelineId, versionId)
}

// Creates a pipeline, but does not create a pipeline version.
// Call CreatePipelineVersion to create a pipeline version.
func (r *ResourceManager) CreatePipeline(p *model.Pipeline) (*model.Pipeline, error) {
	if p.Name == "" {
		return nil, util.NewInvalidInputError("pipeline's name cannot be empty")
	}
	// Create a record in KFP DB (only pipelines table)
	newPipeline, err := r.pipelineStore.CreatePipeline(p)
	if err != nil {
		return nil, util.Wrap(err, "Failed to create a pipeline in PipelineStore")
	}

	newPipeline.Status = model.PipelineReady
	err = r.pipelineStore.UpdatePipelineStatus(
		newPipeline.UUID,
		newPipeline.Status,
	)
	if err != nil {
		return nil, util.Wrap(err, "Failed to update status of a pipeline after creation")
	}
	return newPipeline, nil
}

// Creates a pipeline and a pipeline version.
// This is used when two resources need to be created in a single DB transaction.
func (r *ResourceManager) CreatePipelineAndPipelineVersion(p *model.Pipeline, pv *model.PipelineVersion) (*model.Pipeline, *model.PipelineVersion, error) {
	// Fetch pipeline spec, verify it, and parse parameters
	pipelineSpecBytes, pipelineSpecURI, err := r.fetchTemplateFromPipelineVersion(pv)
	if err != nil {
		return nil, nil, util.Wrap(err, "Failed to create a pipeline and a pipeline version as template is broken")
	}
	pv.PipelineSpec = string(pipelineSpecBytes)
	if pipelineSpecURI != "" {
		pv.PipelineSpecURI = pipelineSpecURI
	}
	tmpl, err := template.New(pipelineSpecBytes)
	if err != nil {
		return nil, nil, util.Wrap(err, "Failed to create a pipeline and a pipeline version due to template creation error")
	}
	// Validate pipeline's name in:
	// 1. pipeline spec for v2 pipelines and v2-compatible pipeline must comply with MLMD requirements
	// 2. display name must be non-empty
	pipelineSpecName := ""
	if tmpl.IsV2() {
		pipelineSpecName = tmpl.V2PipelineName()
		if err := common.ValidatePipelineName(pipelineSpecName); err != nil {
			return nil, nil, err
		}
	}
	if pv.Name == "" && p.Name == "" {
		if pipelineSpecName == "" {
			return nil, nil, util.NewInvalidInputError("pipeline's name cannot be empty")
		}
		pv.Name = pipelineSpecName
		p.Name = pipelineSpecName
	} else if pv.Name == "" {
		pv.Name = p.Name
	} else if p.Name == "" {
		p.Name = pv.Name
	}
	// Parse parameters
	paramsJSON, err := tmpl.ParametersJSON()
	if err != nil {
		return nil, nil, util.Wrap(err, "Failed to create a pipeline and a pipeline version due to error converting parameters to json")
	}
	pv.Parameters = paramsJSON
	pv.PipelineSpec = string(tmpl.Bytes())

	// Create records in KFP DB (both pipelines and pipeline_versions tables)
	newPipeline, newVersion, err := r.pipelineStore.CreatePipelineAndPipelineVersion(p, pv)
	if err != nil {
		return nil, nil, util.Wrap(err, "Failed to create a pipeline and a pipeline version")
	}

	newPipeline.Status = model.PipelineReady
	err = r.pipelineStore.UpdatePipelineStatus(
		newPipeline.UUID,
		newPipeline.Status,
	)
	if err != nil {
		return nil, nil, util.Wrap(err, "Failed to update status of a new pipeline after creation")
	}
	newVersion.Status = model.PipelineVersionReady
	err = r.pipelineStore.UpdatePipelineVersionStatus(
		newVersion.UUID,
		newVersion.Status,
	)
	if err != nil {
		return nil, nil, util.Wrap(err, "Failed to update status of a new pipeline version after creation")
	}
	return newPipeline, newVersion, nil
}

// Updates the status of a pipeline.
func (r *ResourceManager) UpdatePipelineStatus(pipelineId string, status model.PipelineStatus) error {
	err := r.pipelineStore.UpdatePipelineStatus(pipelineId, status)
	if err != nil {
		return util.Wrapf(err, "Failed to update the status of pipeline id %v to %v", pipelineId, status)
	}
	return nil
}

// Updates the status of a pipeline version.
func (r *ResourceManager) UpdatePipelineVersionStatus(pipelineVersionId string, status model.PipelineVersionStatus) error {
	err := r.pipelineStore.UpdatePipelineVersionStatus(pipelineVersionId, status)
	if err != nil {
		return util.Wrapf(err, "Failed to update the status of pipeline version id %v to %v", pipelineVersionId, status)
	}
	return nil
}

// Returns the latest template for a specified pipeline id.
func (r *ResourceManager) GetPipelineLatestTemplate(pipelineId string) ([]byte, error) {
	// Verify pipeline exists
	_, err := r.pipelineStore.GetPipeline(pipelineId)
	if err != nil {
		return nil, util.Wrap(err, "Failed to get the latest template as pipeline was not found")
	}

	// Get the latest pipeline version
	latestPipelineVersion, err := r.pipelineStore.GetLatestPipelineVersion(pipelineId)
	if err != nil {
		return nil, util.Wrap(err, "Failed to get the latest template for a pipeline")
	}

	// Fetch template []byte array
	if bytes, _, err := r.fetchTemplateFromPipelineVersion(latestPipelineVersion); err != nil {
		return nil, util.Wrapf(err, "Failed to get the latest template for pipeline with id %v", pipelineId)
	} else {
		return bytes, nil
	}
}

// Creates a run and schedule a workflow CR.
// Manifest's namespace gets overwritten with the run.Namespace.
// Creating a run from recurring run prioritizes recurring run's pipeline spec over the run's one.
func (r *ResourceManager) CreateRun(ctx context.Context, run *model.Run) (*model.Run, error) {
	// Create a template based on the manifest of an existing pipeline version or used-provided manifest.
	// Update the run.PipelineSpec if an existing pipeline version is used.
	tmpl, manifest, err := r.fetchTemplateFromPipelineSpec(&run.PipelineSpec)
	if err != nil {
		return nil, util.NewInternalServerError(err, "Failed to create a run due to error fetching manifest")
	}

	// TODO(gkcalat): consider changing the flow. Other resource UUIDs are assigned by their respective stores (DB).
	// Proposed flow:
	// 1. Create an entry and assign creation timestamp and uuid.
	// 2. Create a workflow CR.
	// 3. Update a record in the DB with scheduled timestamp, state, etc.
	// 4. Persistence agent will call apiserver to update the records later.
	if run.UUID == "" {
		uuid, err := r.uuid.NewRandom()
		if err != nil {
			return nil, util.NewInternalServerError(err, "Failed to generate run ID")
		}
		run.UUID = uuid.String()
	}
	run.RunDetails.CreatedAtInSec = r.time.Now().Unix()
	runWorkflowOptions := template.RunWorkflowOptions{
		RunId: run.UUID,
		RunAt: run.RunDetails.CreatedAtInSec,
	}
	executionSpec, err := tmpl.RunWorkflow(run, runWorkflowOptions)
	if err != nil {
		return nil, util.Wrap(err, "Failed to generate the ExecutionSpec")
	}
	err = executionSpec.Validate(false, false)
	if err != nil {
		return nil, util.NewInternalServerError(err, "Failed to validate workflow for (%+v)", executionSpec.ExecutionName())
	}
	// Create argo workflow CR resource
	k8sNamespace := run.Namespace
	if k8sNamespace == "" {
		k8sNamespace = common.GetPodNamespace()
	}
	if k8sNamespace == "" {
		return nil, util.NewInternalServerError(util.NewInvalidInputError("Namespace cannot be empty when creating an Argo workflow. Check if you have specified POD_NAMESPACE or try adding the parent namespace to the request"), "Failed to create a run due to empty namespace")
	}
	executionSpec.SetExecutionNamespace(k8sNamespace)

	// assign OwnerReference to scheduledworkflow
	if run.RecurringRunId != "" {
		job, err := r.jobStore.GetJob(run.RecurringRunId)
		if err != nil {
			return nil, util.NewInternalServerError(util.NewInvalidInputError("RecurringRunId doesn't exist: %s", run.RecurringRunId), "Failed to create a run due to invalid recurring run id")
		}
		swf, err := r.swfClient.ScheduledWorkflow(job.Namespace).Get(ctx, job.K8SName, v1.GetOptions{})
		if err != nil {
			return nil, util.NewInternalServerError(util.NewInvalidInputError("ScheduledWorkflow doesn't exist: %s", job.K8SName), "Failed to create a run due to invalid name")
		}
		executionSpec.SetOwnerReferences(swf)
	}

	newExecSpec, err := r.getWorkflowClient(k8sNamespace).Create(ctx, executionSpec, v1.CreateOptions{})
	if err != nil {
		if err, ok := err.(net.Error); ok && err.Timeout() {
			return nil, util.NewUnavailableServerError(err, "Failed to create a workflow for (%s) - try again later", executionSpec.ExecutionName())
		}
		return nil, util.NewInternalServerError(err, "Failed to create a workflow for (%s)", executionSpec.ExecutionName())
	}
	// Update the run with the new scheduled workflow
	run.K8SName = newExecSpec.ExecutionName()
	run.ServiceAccount = newExecSpec.ServiceAccount()
	run.RunDetails.State = model.RuntimeState(string(newExecSpec.ExecutionStatus().Condition())).ToV2()
	run.RunDetails.Conditions = string(run.RunDetails.State.ToV1())
	// TODO(gkcalat): consider to avoid updating runtime manifest at create time and let
	// persistence agent update the runtime data.
	if tmpl.GetTemplateType() == template.V1 && run.RunDetails.WorkflowRuntimeManifest == "" {
		run.RunDetails.WorkflowRuntimeManifest = newExecSpec.ToStringForStore()
		run.PipelineSpec.WorkflowSpecManifest = manifest
	} else if tmpl.GetTemplateType() == template.V2 {
		run.RunDetails.PipelineRuntimeManifest = newExecSpec.ToStringForStore()
		run.PipelineSpec.PipelineSpecManifest = manifest
	} else {
		run.PipelineSpec.PipelineSpecManifest = manifest
	}
	// Assign the scheduled at time
	if run.RunDetails.ScheduledAtInSec == 0 {
		// if there is no scheduled time, then we assume this run is scheduled at the same time it is created
		run.RunDetails.ScheduledAtInSec = run.RunDetails.CreatedAtInSec
	}
	run.State = model.RuntimeStatePending
	newRun, err := r.runStore.CreateRun(run)
	if err != nil {
		return nil, util.Wrap(err, "Failed to create a run")
	}

	// Upon run creation, update owning experiment
	err = r.experimentStore.SetLastRunTimestamp(newRun)
	if err != nil {
		return nil, util.Wrap(err, fmt.Sprintf("Failed to set last run timestamp on experiment %s for run %s", newRun.ExperimentId, newRun.UUID))
	}

	return newRun, nil
}

// ReconcileSwfCrs reconciles the ScheduledWorkflow CRs based on existing jobs.
func (r *ResourceManager) ReconcileSwfCrs(ctx context.Context) error {
	filterContext := &model.FilterContext{
		ReferenceKey: &model.ReferenceKey{Type: model.NamespaceResourceType, ID: common.GetPodNamespace()},
	}

	opts := list.EmptyOptions()

	jobs, _, _, err := r.jobStore.ListJobs(filterContext, opts)

	if err != nil {
		return util.Wrap(err, "Failed to reconcile ScheduledWorkflow Kubernetes resources")
	}

	for i := range jobs {
		select {
		case <-ctx.Done():
			return nil
		default:
		}

		tmpl, _, err := r.fetchTemplateFromPipelineSpec(&jobs[i].PipelineSpec)
		if err != nil {
			return failedToReconcileSwfCrsError(err)
		}

		newScheduledWorkflow, err := tmpl.ScheduledWorkflow(jobs[i])
		if err != nil {
			return failedToReconcileSwfCrsError(err)
		}

		for {
			currentScheduledWorkflow, err := r.getScheduledWorkflowClient(jobs[i].Namespace).Get(ctx, jobs[i].K8SName, v1.GetOptions{})
			if err != nil {
				if util.IsNotFound(err) {
					break
				}
				return failedToReconcileSwfCrsError(err)
			}

			if !reflect.DeepEqual(currentScheduledWorkflow.Spec, newScheduledWorkflow.Spec) {
				currentScheduledWorkflow.Spec = newScheduledWorkflow.Spec
				err = r.updateSwfCrSpec(ctx, jobs[i].Namespace, currentScheduledWorkflow)
				if err != nil {
					if apierrors.IsConflict(errors.Unwrap(err)) {
						continue
					} else if util.IsNotFound(errors.Cause(err)) {
						break
					}
					return failedToReconcileSwfCrsError(err)
				}
			}
			break
		}
	}

	return nil
}

func failedToReconcileSwfCrsError(err error) error {
	return util.Wrap(err, "Failed to reconcile ScheduledWorkflow Kubernetes resources")
}

func (r *ResourceManager) updateSwfCrSpec(ctx context.Context, k8sNamespace string, scheduledWorkflow *scheduledworkflow.ScheduledWorkflow) error {
	_, err := r.getScheduledWorkflowClient(k8sNamespace).Update(ctx, scheduledWorkflow)
	if err != nil {
		return util.Wrap(err, "Failed to update ScheduledWorkflow")
	}
	return nil
}

// Fetches a run with a given id.
func (r *ResourceManager) GetRun(runId string) (*model.Run, error) {
	run, err := r.runStore.GetRun(runId)
	if err != nil {
		return nil, util.Wrapf(err, "Failed to fetch run %v", runId)
	}
	return run, nil
}

// Fetches runs with a given set of filtering and listing options.
func (r *ResourceManager) ListRuns(filterContext *model.FilterContext, opts *list.Options) ([]*model.Run, int, string, error) {
	runs, totalSize, nextPageToken, err := r.runStore.ListRuns(filterContext, opts)
	if err != nil {
		return nil, 0, "", util.Wrap(err, "Failed to list runs")
	}
	return runs, totalSize, nextPageToken, nil
}

// Archives a run with a given id.
func (r *ResourceManager) ArchiveRun(runId string) error {
	if _, err := r.GetRun(runId); err != nil {
		return util.Wrapf(err, "Failed to archive run %v as it failed to be retrieved", runId)
	}
	if err := r.runStore.ArchiveRun(runId); err != nil {
		return util.Wrapf(err, "Failed to archive run %v", runId)
	}
	return nil
}

// Un-archives a run with a given id.
func (r *ResourceManager) UnarchiveRun(runId string) error {
	run, err := r.GetRun(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to unarchive run %v as it does not exist", runId)
	}
	if run.ExperimentId == "" {
		experimentRef, err := r.resourceReferenceStore.GetResourceReference(runId, model.RunResourceType, model.ExperimentResourceType)
		if err != nil {
			return util.Wrapf(err, "Failed to unarchive run %v due to resource references fetching error", runId)
		}
		run.ExperimentId = experimentRef.ReferenceUUID
	}

	experiment, err := r.GetExperiment(run.ExperimentId)
	if err != nil {
		return util.Wrapf(err, "Failed to unarchive run %v due to experiment fetching error", runId)
	}
	if experiment.StorageState.ToV2() == model.StorageStateArchived {
		return util.NewFailedPreconditionError(
			errors.New("Unarchive the experiment first to allow the run to be restored"),
			fmt.Sprintf("Failed to unarchive run %v as experiment %v must be un-archived first", runId, run.ExperimentId),
		)
	}
	if err := r.runStore.UnarchiveRun(runId); err != nil {
		return util.Wrapf(err, "Failed to unarchive run %v", runId)
	}
	return nil
}

// Deletes a run entry with a given id.
func (r *ResourceManager) DeleteRun(ctx context.Context, runId string) error {
	run, err := r.GetRun(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to delete run %v as it does not exist", runId)
	}
	if run.Namespace == "" {
		namespace, err := r.GetNamespaceFromExperimentId(run.ExperimentId)
		if err != nil {
			return util.Wrapf(err, "Failed to delete a run %v due to namespace fetching error", runId)
		}
		run.Namespace = namespace
	}
	k8sNamespace := run.Namespace
	if k8sNamespace == "" {
		k8sNamespace = common.GetPodNamespace()
	}
	err = r.getWorkflowClient(k8sNamespace).Delete(ctx, run.K8SName, v1.DeleteOptions{})
	if err != nil {
		// API won't need to delete the workflow CR
		// once persistent agent sync the state to DB and set TTL for it.
		glog.Warningf("Failed to delete run %v. Error: %v", run.K8SName, err.Error())
	}
	err = r.runStore.DeleteRun(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to delete a run %v", runId)
	}

	if r.options.CollectMetrics {
		if run.Conditions == string(exec.ExecutionSucceeded) {
			if util.GetMetricValue(workflowSuccessCounter) > 0 {
				workflowSuccessCounter.WithLabelValues(run.Namespace, run.DisplayName).Dec()
			}
		} else {
			if util.GetMetricValue(workflowFailedCounter) > 0 {
				workflowFailedCounter.WithLabelValues(run.Namespace, run.DisplayName).Dec()
			}
		}
	}
	return nil
}

// Creates a task entry.
func (r *ResourceManager) CreateTask(t *model.Task) (*model.Task, error) {
	run, err := r.GetRun(t.RunId)
	if err != nil {
		return nil, util.Wrapf(err, "Failed to create a task for run %v", t.RunId)
	}
	if run.ExperimentId == "" {
		defaultExperimentId, err := r.GetDefaultExperimentId()
		if err != nil {
			return nil, util.Wrapf(err, "Failed to create a task in run %v. Specify experiment id for the run or check if the default experiment exists", t.RunId)
		}
		run.ExperimentId = defaultExperimentId
	}

	// Validate namespace
	if t.Namespace == "" {
		namespace, err := r.GetNamespaceFromExperimentId(run.ExperimentId)
		if err != nil {
			return nil, util.Wrapf(err, "Failed to create a task in run %v", t.RunId)
		}
		t.Namespace = namespace
	}
	if common.IsMultiUserMode() {
		if t.Namespace == "" {
			return nil, util.NewInternalServerError(util.NewInvalidInputError("Task cannot have an empty namespace in multi-user mode"), "Failed to create a task in run %v", t.RunId)
		}
	}
	if err := r.CheckExperimentBelongsToNamespace(run.ExperimentId, t.Namespace); err != nil {
		return nil, util.Wrapf(err, "Failed to create a task in run %v", t.RunId)
	}

	newTask, err := r.taskStore.CreateTask(t)
	if err != nil {
		return nil, util.Wrapf(err, "Failed to create a task in run %v", t.RunId)
	}
	return newTask, nil
}

// Fetches tasks with a given set of filtering and listing options.
func (r *ResourceManager) ListTasks(filterContext *model.FilterContext, opts *list.Options) ([]*model.Task, int, string, error) {
	tasks, totalSize, nextPageToken, err := r.taskStore.ListTasks(filterContext, opts)
	if err != nil {
		return nil, 0, "", util.Wrap(err, "Failed to list tasks")
	}
	return tasks, totalSize, nextPageToken, nil
}

// Fetches recurring runs with given filtering and listing options.
func (r *ResourceManager) ListJobs(filterContext *model.FilterContext, opts *list.Options) ([]*model.Job, int, string, error) {
	return r.jobStore.ListJobs(filterContext, opts)
}

// Terminates a workflow by setting its activeDeadlineSeconds to 0.
func TerminateWorkflow(ctx context.Context, wfClient util.ExecutionInterface, name string) error {
	patchObj := util.GetTerminatePatch(util.CurrentExecutionType())
	patch, err := json.Marshal(patchObj)
	if err != nil {
		return util.NewInternalServerError(err, "Failed to terminate workflow %s due to error parsing the patch", name)
	}
	operation := func() error {
		_, err = wfClient.Patch(ctx, name, types.MergePatchType, patch, v1.PatchOptions{})
		return util.Wrapf(err, "Failed to terminate workflow %s due to patching error", name)
	}
	backoffPolicy := backoff.WithMaxRetries(backoff.NewConstantBackOff(100), 10)
	err = backoff.Retry(operation, backoffPolicy)
	if err != nil {
		return util.Wrapf(err, "Failed to terminate workflow %s due to patching error after multiple retries", name)
	}
	return nil
}

// Terminates a running run and the corresponding workflow.
func (r *ResourceManager) TerminateRun(ctx context.Context, runId string) error {
	run, err := r.GetRun(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to terminate run %s due to error fetching the run", runId)
	}
	// TODO(gkcalat): consider using run.Namespace after migration logic will be available.
	namespace, err := r.getNamespaceFromRunId(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to terminate run %s due to error fetching its namespace", runId)
	}

	err = r.runStore.TerminateRun(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to terminate run %s", runId)
	}

	if namespace == "" {
		namespace = common.GetPodNamespace()
	}
	err = TerminateWorkflow(ctx, r.getWorkflowClient(namespace), run.K8SName)
	if err != nil {
		return util.NewInternalServerError(err, "Failed to terminate run %s due to error terminating its workflow", runId)
	}
	return nil
}

// Retries a run given its id.
func (r *ResourceManager) RetryRun(ctx context.Context, runId string) error {
	run, err := r.GetRun(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to retry run %s due to error fetching the run", runId)
	}
	// TODO(gkcalat): consider using run.Namespace after migration logic will be available.
	namespace, err := r.getNamespaceFromRunId(runId)
	if err != nil {
		return util.Wrapf(err, "Failed to retry run %s due to error fetching its namespace", runId)
	}

	if run.RunDetails.WorkflowRuntimeManifest == "" {
		return util.NewBadRequestError(util.NewInvalidInputError("Workflow manifest cannot be empty"), "Failed to retry run %s due to error fetching workflow manifest", runId)
	}
	execSpec, err := util.NewExecutionSpecJSON(util.ArgoWorkflow, []byte(run.RunDetails.WorkflowRuntimeManifest))
	if err != nil {
		return util.NewInternalServerError(err, "Failed to retry run %s due to error parsing the workflow manifest", runId)
	}

	if err := execSpec.Decompress(); err != nil {
		return util.NewInternalServerError(err, "Failed to retry run %s due to error decompressing execution spec", runId)
	}

	if err := execSpec.CanRetry(); err != nil {
		return util.NewInternalServerError(err, "Failed to retry run %s as it does not allow reties", runId)
	}

	newExecSpec, podsToDelete, err := execSpec.GenerateRetryExecution()
	if err != nil {
		return util.Wrapf(err, "Failed to retry run %s", runId)
	}

	if namespace == "" {
		namespace = common.GetPodNamespace()
	}
	if err = deletePods(ctx, r.k8sCoreClient, podsToDelete, namespace); err != nil {
		return util.NewInternalServerError(err, "Failed to retry run %s due to error cleaning up the failed pods from the previous attempt", runId)
	}

	// First try to update workflow
	// If fail to get the workflow, return error.
	latestWorkflow, updateError := r.getWorkflowClient(namespace).Get(ctx, newExecSpec.ExecutionName(), v1.GetOptions{})
	if updateError == nil {
		// Update the workflow's resource version to latest.
		newExecSpec.SetVersion(latestWorkflow.Version())
		_, updateError = r.getWorkflowClient(namespace).Update(ctx, newExecSpec, v1.UpdateOptions{})
	}
	if updateError != nil {
		// Remove resource version
		newExecSpec.SetVersion("")
		newCreatedWorkflow, createError := r.getWorkflowClient(namespace).Create(ctx, newExecSpec, v1.CreateOptions{})
		if createError != nil {
			if createError, ok := createError.(net.Error); ok && createError.Timeout() {
				return util.NewUnavailableServerError(createError, "Failed to retry run %s due to error creating and updating a workflow - try again later. Update error: %s", runId, updateError.Error())
			}
			return util.NewInternalServerError(createError, "Failed to retry run %s due to error updating and creating a workflow. Update error: %s", runId, updateError.Error())
		}
		newExecSpec = newCreatedWorkflow
	}
	condition := string(newExecSpec.ExecutionStatus().Condition())
	err = r.runStore.UpdateRun(&model.Run{UUID: runId, RunDetails: model.RunDetails{Conditions: condition, FinishedAtInSec: 0, WorkflowRuntimeManifest: newExecSpec.ToStringForStore(), State: model.RuntimeState(condition).ToV2()}})
	if err != nil {
		return util.NewInternalServerError(err, "Failed to retry run %s due to error updating entry", runId)
	}
	return nil
}

// Fetches execution logs and writes to the destination.
// 1. Attempts to read logs directly from pod.
// 2. Attempts to read logs from archive if reading from pod fails.
func (r *ResourceManager) ReadLog(ctx context.Context, runId string, nodeId string, follow bool, dst io.Writer) error {
	run, err := r.GetRun(runId)
	if err != nil {
		return util.NewBadRequestError(err, "Failed to read logs for run %v due to run fetching error", runId)
	}
	// TODO(gkcalat): consider using run.Namespace after migration logic will be available.
	namespace, err := r.getNamespaceFromRunId(runId)
	if err != nil {
		return util.NewBadRequestError(err, "Failed to read logs for run %v due to namespace fetching error", runId)
	}
	err = r.readRunLogFromPod(ctx, namespace, nodeId, follow, dst)
	if err != nil && r.logArchive != nil {
		err = r.readRunLogFromArchive(run.WorkflowRuntimeManifest, nodeId, dst)
		if err != nil {
			return util.NewBadRequestError(err, "Failed to read logs for run %v", runId)
		}
	}
	if err != nil {
		return util.NewBadRequestError(err, "Failed to read logs for run %v", runId)
	}
	return nil
}

// Fetches execution logs from a pod.
func (r *ResourceManager) readRunLogFromPod(ctx context.Context, namespace string, nodeId string, follow bool, dst io.Writer) error {
	logOptions := corev1.PodLogOptions{
		Container:  "main",
		Timestamps: false,
		Follow:     follow,
	}

	req := r.k8sCoreClient.PodClient(namespace).GetLogs(nodeId, &logOptions)
	podLogs, err := req.Stream(ctx)
	if err != nil {
		if !apierrors.IsNotFound(err) {
			glog.Errorf("Failed to read logs from pod %v: %v", nodeId, err)
		}
		return util.NewInternalServerError(err, "Failed to read logs from pod %v due to error opening log stream", nodeId)
	}
	defer podLogs.Close()

	_, err = io.Copy(dst, podLogs)
	if err != nil && !errors.Is(err, io.EOF) {
		return util.NewInternalServerError(err, "Failed to read logs from pod %v due to error in streaming the log", nodeId)
	}
	return nil
}

// Fetches execution logs from a archived pod logs.
func (r *ResourceManager) readRunLogFromArchive(workflowManifest string, nodeId string, dst io.Writer) error {
	if workflowManifest == "" {
		return util.NewInternalServerError(util.NewInvalidInputError("Runtime workflow manifest cannot empty"), "Failed to read logs from archive %v due to empty runtime workflow manifest", nodeId)
	}

	execSpec, err := util.NewExecutionSpecJSON(util.CurrentExecutionType(), []byte(workflowManifest))
	if err != nil {
		return util.NewInternalServerError(err, "Failed to read logs from archive %v due error reading execution spec", nodeId)
	}

	logPath, err := r.logArchive.GetLogObjectKey(execSpec, nodeId)
	if err != nil {
		return util.NewInternalServerError(err, "Failed to read logs from archive %v", nodeId)
	}

	logContent, err := r.objectStore.GetFile(logPath)
	if err != nil {
		return util.NewInternalServerError(err, "Failed to read logs from archive %v due to error fetching the log file", nodeId)
	}

	err = r.logArchive.CopyLogFromArchive(logContent, dst, archive.ExtractLogOptions{LogFormat: archive.LogFormatText, Timestamps: false})
	if err != nil {
		return util.NewInternalServerError(err, "Failed to read logs from archive %v due to error copying the log file", nodeId)
	}
	return nil
}

// Fetches a recurring run with given id.
func (r *ResourceManager) GetJob(id string) (*model.Job, error) {
	return r.jobStore.GetJob(id)
}

// Fetches or creates a new pipeline version based on internal PipelineSpec representation.
// Returns a pipeline version if any of the following is present in pipeline spec:
// 1. Pipeline version with the given pipeline version id
// 2. The latest pipeline version with given pipeline id
// 3. Repeats 1 and 2 for pipeline version id and pipeline id parsed from the pipeline name
func (r *ResourceManager) fetchPipelineVersionFromPipelineSpec(pipelineSpec model.PipelineSpec) (*model.PipelineVersion, error) {
	// Fetch or create a pipeline version
	if pipelineSpec.PipelineVersionId != "" {
		pipelineVersion, err := r.GetPipelineVersion(pipelineSpec.PipelineVersionId)
		if err != nil {
			return nil, util.Wrapf(err, "Failed to fetch a pipeline version and its manifest from pipeline version %v", pipelineSpec.PipelineVersionId)
		}
		// Requests in v1beta1 may have empty pipeline ID. Therefore, we only catch
		// v2beta1 calls to create a run or recurring run with inconsistent pipeline ID.
		if pipelineVersion.PipelineId != "" && pipelineSpec.PipelineId != "" && pipelineVersion.PipelineId != pipelineSpec.PipelineId {
			return nil, util.NewInvalidInputError("Pipeline version %v belongs to pipeline %v (not %v)", pipelineSpec.PipelineVersionId, pipelineVersion.PipelineId, pipelineSpec.PipelineId)
		}
		return pipelineVersion, nil
	} else if pipelineSpec.PipelineId != "" {
		pipelineVersion, err := r.GetLatestPipelineVersion(pipelineSpec.PipelineId)
		if err != nil {
			return nil, util.Wrapf(err, "Failed to fetch a pipeline version and its manifest from pipeline %v", pipelineSpec.PipelineId)
		}
		return pipelineVersion, nil
	} else if pipelineSpec.PipelineName != "" {
		resourceNames := common.ParseResourceIdsFromFullName(pipelineSpec.PipelineName)
		if resourceNames["PipelineVersionId"] == "" && resourceNames["PipelineId"] == "" {
			return nil, util.Wrapf(util.NewInvalidInputError("Pipeline spec source is missing"), "Failed to fetch a pipeline version and its manifest due to an empty pipeline spec source: %v", pipelineSpec.PipelineName)
		}
		if resourceNames["PipelineVersionId"] != "" {
			pipelineVersion, err := r.GetPipelineVersion(resourceNames["PipelineVersionId"])
			if err != nil {
				return nil, util.Wrapf(err, "Failed to fetch a pipeline version and its manifest from pipeline %v. Check if pipeline version %v exists", pipelineSpec.PipelineName, resourceNames["PipelineVersionId"])
			}
			return pipelineVersion, nil
		} else {
			pipelineVersion, err := r.GetLatestPipelineVersion(resourceNames["PipelineId"])
			if err != nil {
				return nil, util.Wrapf(err, "Failed to fetch a pipeline version and its manifest from pipeline %v. Check if pipeline %v exists", pipelineSpec.PipelineName, resourceNames["PipelineId"])
			}
			return pipelineVersion, nil
		}
	}
	return nil, nil
}

// Creates a recurring run.
// Manifest's namespace gets overwritten with the job.Namespace if the later is non-empty.
// Otherwise, job.Namespace gets overwritten by the manifest.
func (r *ResourceManager) CreateJob(ctx context.Context, job *model.Job) (*model.Job, error) {
	// Create a template based on the manifest of an existing pipeline version or used-provided manifest.
	// Update the job.PipelineSpec if an existing pipeline version is used.
	tmpl, manifest, err := r.fetchTemplateFromPipelineSpec(&job.PipelineSpec)
	if err != nil {
		return nil, util.NewInternalServerError(err, "Failed to create a recurring run with an invalid pipeline spec manifest")
	}

	// Create a new ScheduledWorkflow at the ScheduledWorkflow client.
	k8sNamespace := job.Namespace
	if k8sNamespace == "" {
		k8sNamespace = common.GetPodNamespace()
	}
	if k8sNamespace == "" {
		return nil, util.NewInternalServerError(util.NewInvalidInputError("Namespace cannot be empty when creating an Argo scheduled workflow. Check if you have specified POD_NAMESPACE or try adding the parent namespace to the request"), "Failed to create a recurring run due to empty namespace")
	}

	job.Namespace = k8sNamespace

	// TODO(gkcalat): consider changing the flow. Other resource UUIDs are assigned by their respective stores (DB).
	// Convert modelJob into scheduledWorkflow.
	scheduledWorkflow, err := tmpl.ScheduledWorkflow(job)
	if err != nil {
		return nil, util.Wrap(err, "Failed to create a recurring run during scheduled workflow creation")
	}
	newScheduledWorkflow, err := r.getScheduledWorkflowClient(k8sNamespace).Create(ctx, scheduledWorkflow)
	if err != nil {
		if err, ok := err.(net.Error); ok && err.Timeout() {
			return nil, util.NewUnavailableServerError(err, "Failed to create a recurring run during scheduling a workflow - try again later")
		}
		return nil, util.Wrap(err, "Failed to create a recurring run during scheduling a workflow")
	}
	// Complete modelJob with info coming back from ScheduledWorkflow client.
	swf := util.NewScheduledWorkflow(newScheduledWorkflow)
	job.UUID = string(swf.UID)
	job.K8SName = swf.Name
	job.Conditions = model.StatusState(swf.ConditionSummary()).ToString()
	for _, modelRef := range job.ResourceReferences {
		modelRef.ResourceUUID = string(swf.UID)
	}
	if tmpl.GetTemplateType() == template.V1 {
		// Get the service account
		serviceAccount := ""
		if swf.Spec.Workflow != nil {
			execSpec, err := util.ScheduleSpecToExecutionSpec(util.ArgoWorkflow, swf.Spec.Workflow)
			if err == nil {
				serviceAccount = execSpec.ServiceAccount()
			}
		}
		job.ServiceAccount = serviceAccount
		job.PipelineSpec.WorkflowSpecManifest = manifest
	} else {
		job.ServiceAccount = newScheduledWorkflow.Spec.ServiceAccount
		job.PipelineSpec.PipelineSpecManifest = manifest
	}
	return r.jobStore.CreateJob(job)
}

// Enables or disables a recurring run with given id.
func (r *ResourceManager) ChangeJobMode(ctx context.Context, jobId string, enable bool) error {
	job, err := r.GetJob(jobId)
	if err != nil {
		return util.Wrapf(err, "Failed to change recurring run's mode to enable:%v. Check if recurring run %v exists", enable, jobId)
	}
	k8sNamespace := job.Namespace
	if k8sNamespace == "" {
		k8sNamespace = common.GetPodNamespace()
	}
	if enable {
		scheduledWorkflow, err := r.getScheduledWorkflowClient(k8sNamespace).Get(ctx, job.K8SName, v1.GetOptions{})
		if err != nil {
			return util.NewInternalServerError(err, "Failed to enable recurring run %v. Check if the scheduled workflow exists", jobId)
		}
		if scheduledWorkflow == nil || string(scheduledWorkflow.UID) != jobId {
			return util.Wrapf(util.NewResourceNotFoundError("recurring run", job.K8SName), "Failed to enable recurring run %v. Check if its k8s resource exists", jobId)
		}
	}

	_, err = r.getScheduledWorkflowClient(k8sNamespace).Patch(
		ctx,
		job.K8SName,
		types.MergePatchType,
		[]byte(fmt.Sprintf(`{"spec":{"enabled":%s}}`, strconv.FormatBool(enable))),
	)
	if err != nil {
		return util.NewInternalServerError(err, "Failed to change recurring run's %v mode to enable:%v", jobId, enable)
	}

	err = r.jobStore.ChangeJobMode(jobId, enable)
	if err != nil {
		return util.Wrapf(err, "Failed to change recurring run's %v mode to enable:%v", jobId, enable)
	}
	return nil
}

// Deletes a recurring run with given id.
func (r *ResourceManager) DeleteJob(ctx context.Context, jobId string) error {
	job, err := r.GetJob(jobId)
	if err != nil {
		return util.Wrapf(err, "Failed to delete recurring run %v. Check if exists", jobId)
	}

	k8sNamespace := job.Namespace
	if k8sNamespace == "" {
		k8sNamespace = common.GetPodNamespace()
	}
	err = r.getScheduledWorkflowClient(k8sNamespace).Delete(ctx, job.K8SName, &v1.DeleteOptions{})
	if err != nil {
		if !util.IsNotFound(err) {
			return util.NewInternalServerError(err, "Failed to delete recurring run %v. Check if the scheduled workflow exists", jobId)
		}
		// The ScheduledWorkflow was not found.
		glog.Infof("Deleting recurring run '%v', but skipped deleting ScheduledWorkflow '%v' in namespace '%v' (k8s namespace %v) because it was not found", jobId, job.K8SName, job.Namespace, k8sNamespace)
		// Continue the execution, because we want to delete the
		// ScheduledWorkflow. We can skip deleting the ScheduledWorkflow
		// when it no longer exists.
	}
	err = r.jobStore.DeleteJob(jobId)
	if err != nil {
		return util.Wrapf(err, "Failed to delete recurring run %v", jobId)
	}
	return nil
}

// Creates new tasks or updates existing ones.
// This is not a part of internal API exposed to persistence agent only.
func (r *ResourceManager) CreateOrUpdateTasks(t []*model.Task) ([]*model.Task, error) {
	tasks, err := r.taskStore.CreateOrUpdateTasks(t)
	if err != nil {
		return nil, util.Wrap(err, "Failed to create or update tasks")
	}
	return tasks, nil
}

// Reports a workflow CR.
// This is called to update runs.
func (r *ResourceManager) ReportWorkflowResource(ctx context.Context, execSpec util.ExecutionSpec) (util.ExecutionSpec, error) {
	objMeta := execSpec.ExecutionObjectMeta()
	execStatus := execSpec.ExecutionStatus()
	if _, ok := objMeta.Labels[util.LabelKeyWorkflowRunId]; !ok {
		// Skip reporting if the workflow doesn't have the run id label
		return nil, util.NewInvalidInputError("Workflow[%s] missing the Run ID label", execSpec.ExecutionName())
	}
	runId := objMeta.Labels[util.LabelKeyWorkflowRunId]
	jobId := execSpec.ScheduledWorkflowUUIDAsStringOrEmpty()
	// TODO(gkcalat): consider adding namespace validation to catch mismatch in the namespaces and release resources.
	if len(execSpec.ExecutionNamespace()) == 0 {
		return nil, util.NewInvalidInputError("Failed to report a workflow. Namespace is empty")
	}

	if execSpec.PersistedFinalState() {
		// If workflow's final state has being persisted, the workflow should be garbage collected.
		err := r.getWorkflowClient(execSpec.ExecutionNamespace()).Delete(ctx, execSpec.ExecutionName(), v1.DeleteOptions{})
		if err != nil {
			// A fix for kubeflow/pipelines#4484, persistence agent might have an outdated item in its workqueue, so it will
			// report workflows that no longer exist. It's important to return a not found error, so that persistence
			// agent won't retry again.
			if util.IsNotFound(err) {
				return nil, util.NewNotFoundError(err, "Failed to delete the completed workflow for run %s", runId)
			} else {
				return nil, util.NewInternalServerError(err, "Failed to delete the completed workflow for run %s", runId)
			}
		}
		if r.options.CollectMetrics {
			workflowGCCounter.Inc()
		}
	}
	// If the run was Running and got terminated (activeDeadlineSeconds set to 0),
	// ignore its condition and mark it as such
	state := model.RuntimeState(string(execStatus.Condition())).ToV2()
	if execSpec.IsTerminating() {
		state = model.RuntimeState(string(exec.ExecutionPhase(model.RunTerminatingConditionsV1))).ToV2()
	}
	// If run already exists, simply update it
	run, updateError := r.GetRun(runId)
	if updateError == nil {
		run.State = state
		run.Conditions = string(state.ToV1())
		run.FinishedAtInSec = execStatus.FinishedAt()
		run.WorkflowRuntimeManifest = execSpec.ToStringForStore()
		if updateError = r.runStore.UpdateRun(run); updateError != nil {
			return nil, util.Wrapf(updateError, "Failed to report a workflow for existing run %s during updating the run. Check if the run entry is corrupted", runId)
		}
	}
	if jobId == "" {
		// If a run doesn't have job ID, it's a one-time run created by Pipeline API server.
		// In this case the DB entry should already been created when argo workflow CR is created.
		if updateError != nil {
			if !util.IsUserErrorCodeMatch(updateError, codes.NotFound) {
				return nil, util.Wrap(updateError, "Failed to update the run")
			}
			// Handle run not found in run store error.
			// To avoid letting the workflow leak for ever, we need to GC it when its record does not exist in KFP DB.
			glog.Errorf("Cannot find reported workflow name=%q namespace=%q runId=%q in run store. "+
				"Deleting the workflow to avoid resource leaking. "+
				"This can be caused by installing two KFP instances that try to manage the same workflows "+
				"or an unknown bug. If you encounter this, recommend reporting more details in https://github.com/kubeflow/pipelines/issues/6189",
				execSpec.ExecutionName(), execSpec.ExecutionNamespace(), runId)
			if err := r.getWorkflowClient(execSpec.ExecutionNamespace()).Delete(ctx, execSpec.ExecutionName(), v1.DeleteOptions{}); err != nil {
				if util.IsNotFound(err) {
					return nil, util.NewNotFoundError(err, "Failed to delete the obsolete workflow for run %s", runId)
				}
				return nil, util.NewInternalServerError(err, "Failed to delete the obsolete workflow for run %s", runId)
			}

			if r.options.CollectMetrics {
				workflowGCCounter.Inc()
			}
			// Note, persistence agent will not retry reporting this workflow again, because updateError is a not found error.
			return nil, util.Wrapf(updateError, "Failed to report workflow name=%q namespace=%q runId=%q", execSpec.ExecutionName(), execSpec.ExecutionNamespace(), runId)
		}
	} else if run == nil || updateError != nil {
		// TODO(gkcalat): consider adding manifest validation to catch mismatch, as runs should have the same pipeline spec as parent recurring run.
		// Try to fetch the job.
		existingJob, err := r.GetJob(jobId)
		if err != nil {
			return nil, util.Wrapf(err, "Failed to report a workflow for run %s due to error retrieving recurring run %s", runId, jobId)
		}
		experimentId := existingJob.ExperimentId
		namespace := existingJob.Namespace
		pipelineSpec := existingJob.PipelineSpec
		pipelineSpec.WorkflowSpecManifest = execSpec.GetExecutionSpec().ToStringForStore()

		// Try to fetch experiment id from resource references if it is missing.
		if experimentId == "" {
			experimentRef, err := r.resourceReferenceStore.GetResourceReference(jobId, model.JobResourceType, model.ExperimentResourceType)
			if err != nil {
				return nil, util.Wrapf(err, "Failed to retrieve the experiment ID for the job %v that created the run", jobId)
			}
			experimentId = experimentRef.ReferenceUUID
			if namespace == "" {
				if namespaceRef, err := r.resourceReferenceStore.GetResourceReference(jobId, model.JobResourceType, model.NamespaceResourceType); err == nil {
					namespace = namespaceRef.ReferenceUUID
				}
			}
		}
		if experimentId == "" {
			experimentId, err = r.GetDefaultExperimentId()
			if err != nil {
				return nil, util.Wrapf(err, "Failed to report workflow for run %s. Fetching default experiment returned error. Check if you have experiment assigned for job %s", runId, jobId)
			}
		}
		// TODO(gkcalat): consider adding namespace validation to catch mismatch in the namespaces and release resources.
		if namespace == "" {
			namespace, err = r.GetNamespaceFromExperimentId(experimentId)
			if err != nil {
				return nil, util.Wrapf(err, "Failed to report workflow for run %s. Fetching namespace for experiment %s returned error. Check if you have namespace assigned for job %s", runId, experimentId, jobId)
			}
		}
		if namespace == "" {
			namespace = execSpec.ExecutionNamespace()
		}
		// Scheduled time equals created time if it is not specified
		scheduledTimeInSec := execSpec.ScheduledAtInSecOr0()
		if scheduledTimeInSec == 0 {
			scheduledTimeInSec = objMeta.CreationTimestamp.Unix()
		}
		run = &model.Run{
			UUID:           runId,
			ExperimentId:   experimentId,
			RecurringRunId: jobId,
			DisplayName:    execSpec.ExecutionName(),
			K8SName:        execSpec.ExecutionName(),
			StorageState:   model.StorageStateAvailable,
			Namespace:      namespace,
			PipelineSpec:   pipelineSpec,
			RunDetails: model.RunDetails{
				WorkflowRuntimeManifest: execSpec.ToStringForStore(),
				CreatedAtInSec:          objMeta.CreationTimestamp.Unix(),
				ScheduledAtInSec:        scheduledTimeInSec,
				FinishedAtInSec:         execStatus.FinishedAt(),
				Conditions:              string(state.ToV1()),
				State:                   state,
			},
		}
		run, err = r.runStore.CreateRun(run)
		if err != nil {
			return nil, util.Wrapf(err, "Failed to report a workflow due to error creating run %s", runId)
		} else {
			runId = run.UUID
		}
		// Upon run creation, update owning experiment
		if updateError = r.experimentStore.SetLastRunTimestamp(run); updateError != nil {
			return nil, util.Wrapf(updateError, "Failed to report a workflow for existing run %s during updating the owning experiment.", runId)
		}
	}
	if execStatus.IsInFinalState() {
		err := addWorkflowLabel(ctx, r.getWorkflowClient(execSpec.ExecutionNamespace()), execSpec.ExecutionName(), util.LabelKeyWorkflowPersistedFinalState, "true")
		if err != nil {
			message := fmt.Sprintf("Failed to add PersistedFinalState label to workflow %s", execSpec.ExecutionName())
			// A fix for kubeflow/pipelines#4484, persistence agent might have an outdated item in its workqueue, so it will
			// report workflows that no longer exist. It's important to return a not found error, so that persistence
			// agent won't retry again.
			if util.IsNotFound(err) {
				return nil, util.NewNotFoundError(err, message)
			} else {
				return nil, util.Wrapf(err, message)
			}
		}

		if r.options.CollectMetrics {
			execNamespace := execSpec.ExecutionNamespace()
			execName := execSpec.ExecutionName()

			if execStatus.Condition() == exec.ExecutionSucceeded {
				workflowSuccessCounter.WithLabelValues(execNamespace, execName).Inc()
			} else {
				glog.Errorf("pipeline '%s' finished with an error", execName)

				// also collects counts regarding retries
				workflowFailedCounter.WithLabelValues(execNamespace, execName).Inc()
			}
		}
	}
	execSpec.SetLabels("pipeline/runid", runId)
	return execSpec, nil
}

// Adds a label for a workflow.
func addWorkflowLabel(ctx context.Context, wfClient util.ExecutionInterface, name string, labelKey string, labelValue string) error {
	patchObj := map[string]interface{}{
		"metadata": map[string]interface{}{
			"labels": map[string]interface{}{
				labelKey: labelValue,
			},
		},
	}

	patch, err := json.Marshal(patchObj)
	if err != nil {
		return util.NewInternalServerError(err, "Unexpected error while marshalling a patch object")
	}

	operation := func() error {
		_, err = wfClient.Patch(ctx, name, types.MergePatchType, patch, v1.PatchOptions{})
		return err
	}
	backoffPolicy := backoff.WithMaxRetries(backoff.NewConstantBackOff(100), 10)
	err = backoff.Retry(operation, backoffPolicy)
	return err
}

// Updates a recurring run with a scheduled workflow CR.
func (r *ResourceManager) ReportScheduledWorkflowResource(swf *util.ScheduledWorkflow) error {
	// Verify the job exists
	if _, err := r.GetJob(string(swf.UID)); err != nil {
		return util.Wrapf(err, "Failed to report scheduled workflow due to error retrieving recurring run %s", string(swf.UID))
	}
	return r.jobStore.UpdateJob(swf)
}

// Returns a workflow template based on the manifest in the following priority:
// 1. Pipeline spec manifest from an existing pipeline version,
// 2. Pipeline spec manifest or workflow spec manifest provided by a user.
// If an existing pipeline version is found, the referenced pipeline and pipeline version are updated.
func (r *ResourceManager) fetchTemplateFromPipelineSpec(pipelineSpec *model.PipelineSpec) (template.Template, string, error) {
	manifest := ""
	pipelineVersion, err := r.fetchPipelineVersionFromPipelineSpec(*pipelineSpec)
	if err != nil {
		return nil, "", util.Wrapf(err, "Failed to fetch a template due to error retrieving pipeline version")
	} else if pipelineVersion != nil {
		// Update references to the existing pipeline version
		pipelineSpec.PipelineId = pipelineVersion.PipelineId
		pipelineSpec.PipelineVersionId = pipelineVersion.UUID
		pipelineSpec.PipelineName = pipelineVersion.Name
		// Fetch the template from PipelineSpec field or the corresponding YAML file
		tempBytes, _, err := r.fetchTemplateFromPipelineVersion(pipelineVersion)
		if err != nil {
			return nil, "", util.Wrapf(err, "Failed to fetch a template due invalid manifest in pipeline version %v", pipelineSpec.PipelineVersionId)
		}
		manifest = string(tempBytes)
	} else {
		// Read the provided manifest and fail if it is empty
		manifest = pipelineSpec.PipelineSpecManifest
		if manifest == "" {
			manifest = pipelineSpec.WorkflowSpecManifest
		}
		if manifest == "" {
			return nil, "", util.NewInvalidInputError("Failed to fetch a template with an empty pipeline spec manifest")
		}
	}
	tmpl, err := template.New([]byte(manifest))
	if err != nil {
		return nil, "", util.Wrap(err, "Failed to fetch a template with an invalid pipeline spec manifest")
	}
	return tmpl, manifest, nil
}

// Fetches PipelineSpec as []byte array and a new URI of PipelineSpec.
// Returns empty string if PipelineSpec is found via PipelineSpecURI.
// It attempts to fetch PipelineSpec in the following order:
//  1. Directly read from pipeline versions's PipelineSpec field.
//  2. Fetch a yaml file from object store based on pipeline versions's PipelineSpecURI field.
//  3. Fetch a yaml file from object store based on pipeline versions's id.
//  4. Fetch a yaml file from object store based on pipeline's id.
func (r *ResourceManager) fetchTemplateFromPipelineVersion(pipelineVersion *model.PipelineVersion) ([]byte, string, error) {
	if len(pipelineVersion.PipelineSpec) != 0 {
		// Check pipeline spec string first
		bytes := []byte(pipelineVersion.PipelineSpec)
		return bytes, pipelineVersion.PipelineSpecURI, nil
	} else {
		// Try reading object store from pipeline_spec_uri
		template, errUri := r.objectStore.GetFile(pipelineVersion.PipelineSpecURI)
		if errUri != nil {
			// Try reading object store from pipeline_version_id
			template, errUUID := r.objectStore.GetFile(r.objectStore.GetPipelineKey(fmt.Sprint(pipelineVersion.UUID)))
			if errUUID != nil {
				// Try reading object store from pipeline_id
				template, errPipelineId := r.objectStore.GetFile(r.objectStore.GetPipelineKey(fmt.Sprint(pipelineVersion.PipelineId)))
				if errPipelineId != nil {
					return nil, "", util.Wrap(
						util.Wrap(
							util.Wrap(errUri, "Failed to read a file from pipeline_spec_uri"),
							util.Wrap(errUUID, "Failed to read a file from OS with pipeline_version_id").Error(),
						),
						util.Wrap(errPipelineId, "Failed to read a file from OS with pipeline_id").Error(),
					)
				}
				return template, r.objectStore.GetPipelineKey(fmt.Sprint(pipelineVersion.PipelineId)), nil
			}
			return template, r.objectStore.GetPipelineKey(fmt.Sprint(pipelineVersion.UUID)), nil
		}
		return template, "", nil
	}
}

// Creates the default experiment entry.
func (r *ResourceManager) CreateDefaultExperiment(namespace string) (string, error) {
	// First check that we don't already have a default experiment ID in the DB.
	defaultExperimentId, err := r.GetDefaultExperimentId()
	if err != nil {
		return "", util.Wrap(err, "Failed to check if default experiment exists")
	}
	// If default experiment ID is already present, don't fail, simply return.
	if defaultExperimentId != "" {
		glog.Infof("Default experiment already exists! ID: %v", defaultExperimentId)
		return defaultExperimentId, nil
	}

	// Check if an experiment named Default already exists
	defaultExperiment, err := r.experimentStore.GetExperimentByNameNamespace("Default", namespace)
	if err != nil || defaultExperiment == nil {
		// Create the default experiment
		defaultExperiment = &model.Experiment{
			Name:         "Default",
			Description:  "All runs created without specifying an experiment will be grouped here.",
			Namespace:    namespace,
			StorageState: model.StorageStateAvailable,
		}
		defaultExperiment, err = r.CreateExperiment(defaultExperiment)
		if err != nil {
			return "", util.Wrap(err, "Failed to create the default experiment")
		}
	}

	// Set default experiment ID in the DB
	err = r.SetDefaultExperimentId(defaultExperiment.UUID)
	if err != nil {
		return "", util.Wrap(err, "Failed to set default experiment ID")
	}

	glog.Infof("Default experiment is set. ID is: %v", defaultExperiment.UUID)
	return defaultExperiment.UUID, nil
}

// TODO(gkcalat): deprecate this as we no longer have metrics in the v2beta1 run message.
// Read metrics as ordinary artifacts instead.
// Creates a run metric entry.
func (r *ResourceManager) ReportMetric(metric *model.RunMetric) error {
	err := r.runStore.CreateMetric(metric)
	if err != nil {
		return util.Wrap(err, "Failed to report a run metric")
	}
	return nil
}

// ReadArtifact parses run's workflow to find artifact file path and reads the content of the file
// from object store.
func (r *ResourceManager) ReadArtifact(runID string, nodeID string, artifactName string) ([]byte, error) {
	run, err := r.runStore.GetRun(runID)
	if err != nil {
		return nil, err
	}
	if run.WorkflowRuntimeManifest == "" {
		return nil, util.NewInvalidInputError("read artifact from run with v2 IR spec is not supported")
	}
	execSpec, err := util.NewExecutionSpecJSON(util.ArgoWorkflow, []byte(run.WorkflowRuntimeManifest))
	if err != nil {
		// This should never happen.
		return nil, util.NewInternalServerError(
			err, "failed to unmarshal workflow '%s'", run.WorkflowRuntimeManifest)
	}
	artifactPath := execSpec.ExecutionStatus().FindObjectStoreArtifactKeyOrEmpty(nodeID, artifactName)
	if artifactPath == "" {
		return nil, util.NewResourceNotFoundError(
			"artifact", common.CreateArtifactPath(runID, nodeID, artifactName))
	}
	return r.objectStore.GetFile(artifactPath)
}

// Fetches the default experiment id.
func (r *ResourceManager) GetDefaultExperimentId() (string, error) {
	return r.defaultExperimentStore.GetDefaultExperimentId()
}

// Sets the default experiment id.
func (r *ResourceManager) SetDefaultExperimentId(id string) error {
	return r.defaultExperimentStore.SetDefaultExperimentId(id)
}

// Checks if sample pipelines have been loaded.
func (r *ResourceManager) HaveSamplesLoaded() (bool, error) {
	return r.dBStatusStore.HaveSamplesLoaded()
}

// Reports that sample pipelines have been loaded.
func (r *ResourceManager) MarkSampleLoaded() error {
	return r.dBStatusStore.MarkSampleLoaded()
}

// Creates a pipeline version.
// PipelineSpec is stored as a sting inside PipelineVersion in v2beta1.
func (r *ResourceManager) CreatePipelineVersion(pv *model.PipelineVersion) (*model.PipelineVersion, error) {
	// Extract pipeline id
	pipelineId := pv.PipelineId
	if len(pipelineId) == 0 {
		return nil, util.NewInvalidInputError("Failed to create a pipeline version due to missing pipeline id")
	}

	// Fetch pipeline spec
	pipelineSpecBytes, pipelineSpecURI, err := r.fetchTemplateFromPipelineVersion(pv)
	if err != nil {
		return nil, util.Wrap(err, "Failed to create a pipeline version as template is broken")
	}
	pv.PipelineSpec = string(pipelineSpecBytes)
	if pipelineSpecURI != "" {
		pv.PipelineSpecURI = pipelineSpecURI
	}

	// Create a template
	tmpl, err := template.New(pipelineSpecBytes)
	if err != nil {
		return nil, util.Wrap(err, "Failed to create a pipeline version due to template creation error")
	}
	// Validate pipeline's name in:
	// 1. pipeline spec for v2 pipelines and v2-compatible pipeline must comply with MLMD requirements
	// 2. display name must be non-empty
	pipelineSpecName := ""
	if tmpl.IsV2() {
		pipelineSpecName = tmpl.V2PipelineName()
		if err := common.ValidatePipelineName(pipelineSpecName); err != nil {
			return nil, err
		}
	}
	if pv.Name == "" {
		if pipelineSpecName == "" {
			return nil, util.NewInvalidInputError("pipeline version's name cannot be empty")
		}
		pv.Name = pipelineSpecName
	}
	// Parse parameters
	paramsJSON, err := tmpl.ParametersJSON()
	if err != nil {
		return nil, util.Wrap(err, "Failed to create a pipeline version due to error converting parameters to json")
	}
	pv.Parameters = paramsJSON
	pv.Status = model.PipelineVersionCreating
	pv.PipelineSpec = string(tmpl.Bytes())

	// Create a record in DB
	version, err := r.pipelineStore.CreatePipelineVersion(pv)
	if err != nil {
		return nil, util.Wrap(err, "Failed to create pipeline version in PipelineStore")
	}

	// After pipeline version being created in DB and pipeline file being
	// saved in minio server, set this pieline version to status ready.
	version.Status = model.PipelineVersionReady
	err = r.pipelineStore.UpdatePipelineVersionStatus(version.UUID, version.Status)
	if err != nil {
		return nil, util.Wrapf(err, "Failed to change the status of a new pipeline version with id %v", version.UUID)
	}
	return version, nil
}

// Returns a pipeline version.
func (r *ResourceManager) GetPipelineVersion(pipelineVersionId string) (*model.PipelineVersion, error) {
	if pipelineVersion, err := r.pipelineStore.GetPipelineVersion(pipelineVersionId); err != nil {
		return nil, util.Wrapf(err, "Failed to get a pipeline version with id %v", pipelineVersionId)
	} else {
		return pipelineVersion, nil
	}
}

// Returns the latest pipeline version for a specified pipeline id.
func (r *ResourceManager) GetLatestPipelineVersion(pipelineId string) (*model.PipelineVersion, error) {
	// Verify pipeline exists
	_, err := r.pipelineStore.GetPipeline(pipelineId)
	if err != nil {
		return nil, util.Wrap(err, "Failed to get the latest pipeline version as pipeline was not found")
	}

	// Get the latest pipeline version
	latestPipelineVersion, err := r.pipelineStore.GetLatestPipelineVersion(pipelineId)
	if err != nil {
		return nil, util.Wrap(err, "Failed to get the latest pipeline version for a pipeline")
	}
	return latestPipelineVersion, nil
}

// Returns a list of pipeline versions.
func (r *ResourceManager) ListPipelineVersions(pipelineId string, opts *list.Options) ([]*model.PipelineVersion, int, string, error) {
	pipelineVersions, total_size, nextPageToken, err := r.pipelineStore.ListPipelineVersions(pipelineId, opts)
	if err != nil {
		err = util.Wrapf(err, "Failed to list pipeline versions with pipeline id %v, options %v", pipelineId, opts)
	}
	return pipelineVersions, total_size, nextPageToken, err
}

// Deletes a pipeline version and the corresponding PipelineSpec.
func (r *ResourceManager) DeletePipelineVersion(pipelineVersionId string) error {
	// Check if pipeline version exists
	_, err := r.pipelineStore.GetPipelineVersion(pipelineVersionId)
	if err != nil {
		return util.Wrapf(err, "Failed to delete pipeline version with id %v as it was not found", pipelineVersionId)
	}

	// Mark pipeline as deleting so it's not visible to user.
	err = r.pipelineStore.UpdatePipelineVersionStatus(pipelineVersionId, model.PipelineVersionDeleting)
	if err != nil {
		return util.Wrapf(err, "Failed to change the status of pipeline version id %v to DELETING", pipelineVersionId)
	}

	// Delete pipeline spec file and DB entry.
	// Not fail the request if this step failed. A background run will do the cleanup.
	// https://github.com/kubeflow/pipelines/issues/388
	// TODO(jingzhang36): For now (before exposing version API), we have only 1
	// file with both pipeline and version pointing to it;  so it is ok to do
	// the deletion as follows. After exposing version API, we can have multiple
	// versions and hence multiple files, and we shall improve performance by
	// either using async deletion in order for this method to be non-blocking
	// or or exploring other performance optimization tools provided by gcs.
	//

	// Delete the DB entry
	err = r.pipelineStore.DeletePipelineVersion(pipelineVersionId)
	if err != nil {
		glog.Errorf("%v", util.Wrapf(err, "Failed to delete a DB entry for pipeline version id %v", pipelineVersionId))
		return util.Wrapf(err, "Failed to delete a DB entry for pipeline version id %v", pipelineVersionId)
	}
	return nil
}

// Returns a template for a specified pipeline version id.
func (r *ResourceManager) GetPipelineVersionTemplate(pipelineVersionId string) ([]byte, error) {
	// Verify pipeline version exist
	pipelineVersion, err := r.pipelineStore.GetPipelineVersion(pipelineVersionId)
	if err != nil {
		return nil, util.Wrapf(err, "Failed to get pipeline version template as pipeline version id %v was not found", pipelineVersionId)
	}

	// Fetch template []byte array
	if bytes, _, err := r.fetchTemplateFromPipelineVersion(pipelineVersion); err != nil {
		return nil, util.Wrapf(err, "Failed to get a template for pipeline version with id %v", pipelineVersionId)
	} else {
		return bytes, nil
	}
}

// Verifies whether the user identity, which is contained in the context object,
// can perform some action (verb) on a resource (resourceType/resourceName) living in the
// target namespace. If the returned error is nil, the authorization passes. Otherwise,
// authorization fails with a non-nil error.
func (r *ResourceManager) IsAuthorized(ctx context.Context, resourceAttributes *authorizationv1.ResourceAttributes) error {
	if !common.IsMultiUserMode() {
		// Skip authz if not multi-user mode.
		return nil
	}

	if common.IsMultiUserSharedReadMode() &&
		(resourceAttributes.Verb == common.RbacResourceVerbGet ||
			resourceAttributes.Verb == common.RbacResourceVerbList) {
		glog.Infof("Multi-user shared read mode is enabled. Request allowed: %+v", resourceAttributes)
		return nil
	}

	glog.Info("Getting user identity")
	if ctx == nil {
		return util.NewUnauthenticatedError(errors.New("Context is nil"), "Authentication request failed")
	}
	// If the request header contains the user identity, requests are authorized
	// based on the namespace field in the request.
	errlist := make([]error, 0)
	userIdentity := ""
	for _, auth := range r.authenticators {
		identity, err := auth.GetUserIdentity(ctx)
		if err == nil {
			userIdentity = identity

			break
		}
		errlist = append(errlist, err)
	}
	if userIdentity == "" {
		return util.NewUnauthenticatedError(utilerrors.NewAggregate(errlist), "Failed to check authorization. User identity is empty in the request header")
	}

	glog.Infof("User: %s, ResourceAttributes: %+v", userIdentity, resourceAttributes)
	glog.Info("Authorizing request")
	result, err := r.subjectAccessReviewClient.Create(
		ctx,
		&authorizationv1.SubjectAccessReview{
			Spec: authorizationv1.SubjectAccessReviewSpec{
				ResourceAttributes: resourceAttributes,
				User:               userIdentity,
			},
		},
		v1.CreateOptions{},
	)
	if err != nil {
		if netError, ok := err.(net.Error); ok && netError.Timeout() {
			reportErr := util.NewUnavailableServerError(
				err,
				"Failed to create SubjectAccessReview for user '%s' (request: %+v) - try again later",
				userIdentity,
				resourceAttributes,
			)
			glog.Info(reportErr.Error())
			return reportErr
		} else {
			reportErr := util.NewInternalServerError(
				err,
				"Failed to create SubjectAccessReview for user '%s' (request: %+v)",
				userIdentity,
				resourceAttributes,
			)
			glog.Info(reportErr.Error())
			return reportErr
		}
	}
	if !result.Status.Allowed {
		err := util.NewPermissionDeniedError(
			errors.New("Unauthorized access"),
			"User '%s' is not authorized with reason: %s (request: %+v)",
			userIdentity,
			result.Status.Reason,
			resourceAttributes,
		)
		glog.Info(err.Error())
		return err
	}
	glog.Infof("Authorized user '%s': %+v", userIdentity, resourceAttributes)
	return nil
}

// Fetches namespace that an experiment belongs to.
func (r *ResourceManager) GetNamespaceFromExperimentId(experimentId string) (string, error) {
	if experimentId == "" {
		return "", nil
	}
	experiment, err := r.GetExperiment(experimentId)
	if err != nil {
		return "", util.Wrapf(err, "Failed to fetch namespace from experiment %v", experimentId)
	}
	if experiment.Namespace == "" {
		if common.IsMultiUserMode() {
			namespaceRef, err := r.resourceReferenceStore.GetResourceReference(experimentId, model.ExperimentResourceType, model.NamespaceResourceType)
			if err != nil {
				return "", util.Wrapf(err, "Failed to fetch namespace from experiment %v due to resource references fetching error", experimentId)
			}
			if namespaceRef == nil || namespaceRef.ReferenceUUID == "" {
				return "", util.NewInternalServerError(util.NewNotFoundError(errors.New("Namespace is empty"), "Experiment's namespace was not found"), "Failed to fetch a namespace for experiment %v in multi-user mode", experimentId)
			}
			experiment.Namespace = namespaceRef.ReferenceUUID
		} else {
			experiment.Namespace = ""
		}
	}
	return experiment.Namespace, nil
}

// Fetches namespace that a run belongs to.
func (r *ResourceManager) getNamespaceFromRunId(runId string) (string, error) {
	run, err := r.GetRun(runId)
	if err != nil {
		return "", util.Wrapf(err, "Failed to fetch namespace from run %v due to fetching error", runId)
	}
	namespace, err := r.GetNamespaceFromExperimentId(run.ExperimentId)
	if err != nil {
		return "", util.Wrapf(err, "Failed to fetch namespace from run %v", runId)
	}
	return namespace, nil
}

// Returns parent namespace for a pipeline id.
func (r *ResourceManager) FetchNamespaceFromPipelineId(pipelineId string) (string, error) {
	pipeline, err := r.GetPipeline(pipelineId)
	if err != nil {
		return "", util.Wrapf(err, "Failed to get namespace for pipeline id %v", pipelineId)
	}
	return pipeline.Namespace, nil
}

// Returns parent namespace for a pipeline version id.
func (r *ResourceManager) FetchNamespaceFromPipelineVersionId(versionId string) (string, error) {
	pipelineVersion, err := r.GetPipelineVersion(versionId)
	if err != nil {
		return "", util.Wrapf(err, "Failed to get namespace for pipeline version id %v", versionId)
	}
	return r.FetchNamespaceFromPipelineId(pipelineVersion.PipelineId)
}

// Checks if the namespace is empty or equal to `-`.
func (r *ResourceManager) IsEmptyNamespace(namespace string) bool {
	if namespace == "" || namespace == model.NoNamespace {
		return true
	}
	return false
}

// Replaces the namespace to a default value for single-user mode.
func (r *ResourceManager) ReplaceNamespace(namespace string) string {
	if common.IsMultiUserMode() {
		return namespace
	} else {
		return ""
	}
}

// Validates that the provided experiment belongs to the namespace. Returns error otherwise.
// Returns an error in multi-user mode when experimentId and namespace are both empty.
func (r *ResourceManager) CheckExperimentBelongsToNamespace(experimentId string, namespace string) error {
	if experimentId == "" || r.IsEmptyNamespace(namespace) {
		if common.IsMultiUserMode() {
			return util.NewInvalidInputError("Resource cannot have an empty namespace and experiment id in multi-user mode")
		}
		return nil
	}
	experimentNamespace, err := r.GetNamespaceFromExperimentId(experimentId)
	if err != nil {
		return util.Wrapf(err, "Failed to validate the namespace of experiment %s", experimentId)
	}
	if experimentNamespace != "" && experimentNamespace != namespace {
		return util.NewInvalidInputError("Failed to validate the namespace of experiment: experiment %s belongs to namespace '%s' (claimed a different namespace '%s')",
			experimentId, experimentNamespace, namespace)
	}
	return nil
}

// Validates the provided experimentId and namespace. Returns valid values if the provided ones are empty.
// For multi-user more at least one of the input must be non-empty, otherwise, returns an error.
//  1. Validates that given experimentId belongs to namespace if both are not empty
//  2. If experimentId is empty, replaces it with the default experimentId from the given namespace.
//     Creates the default experiment in the given namespace (could be empty in single-user mode) if it is missing.
//  3. Replaces empty namespace with the parent namespace of the given experimentId.
func (r *ResourceManager) GetValidExperimentNamespacePair(experimentId string, namespace string) (string, string, error) {
	if common.IsMultiUserMode() && experimentId == "" {
		return "", "", util.NewInvalidInputError("Experiment id can not be empty in multi-user mode")
	}
	if experimentId != "" {
		ns, err := r.GetNamespaceFromExperimentId(experimentId)
		if err != nil {
			return "", "", util.Wrapf(err, "Failed to fetch namespace for experiment %v", experimentId)
		}
		if namespace != "" && namespace != ns {
			return "", "", util.NewInvalidInputError("Experiment %v belongs to namespace '%v' instead of '%v'", experimentId, ns, namespace)
		}
		namespace = ns
	} else {
		defExpId, err := r.GetDefaultExperimentId()
		if err != nil {
			return "", "", util.Wrapf(err, "Specify experiment id or check if the default experiment exists in namespace %v", namespace)
		}
		// Create the default experiment if it is missing
		if defExpId == "" {
			defExpId, err = r.CreateDefaultExperiment(namespace)
			if err != nil {
				return "", "", util.Wrapf(err, "Experiment id is empty. Failed to create a new default experiment in namespace %v", namespace)
			}
		}
		experimentId = defExpId
	}
	return experimentId, namespace, nil
}

// Fetches a task entry.
func (r *ResourceManager) GetTask(taskId string) (*model.Task, error) {
	task, err := r.taskStore.GetTask(taskId)
	if err != nil {
		return nil, util.Wrapf(err, "Failed to fetch task %v", taskId)
	}
	return task, nil
}