[GSoC] Add New Parameter in tune

hack/gen-python-sdk/post_gen.py

@@ -41,6 +41,8 @@ def _rewrite_helper(input_file, output_file, rewrite_rules):
     if (output_file == "sdk/python/v1beta1/kubeflow/katib/__init__.py"):
         lines.append("# Import Katib API client.\n")
         lines.append("from kubeflow.katib.api.katib_client import KatibClient\n")
+        lines.append("# Import Katib report metrics functions")
+        lines.append("from kubeflow.katib.api.report_metrics import report_metrics")
         lines.append("# Import Katib helper functions.\n")
         lines.append("import kubeflow.katib.api.search as search\n")
         lines.append("# Import Katib helper constants.\n")

pkg/apis/controller/common/v1beta1/common_types.go

@@ -220,8 +220,8 @@ const (
 	CustomCollector CollectorKind = "Custom"
 
 	// When model training source code persists metrics into persistent layer
-	// directly, metricsCollector isn't in need, and its kind is "noneCollector"
-	NoneCollector CollectorKind = "None"
+	// directly, sidecar container isn't in need, and its kind is "pushCollector"
+	PushCollector CollectorKind = "Push"
 
 	MetricsVolume = "metrics-volume"
 )

pkg/controller.v1beta1/consts/const.go

@@ -60,6 +60,9 @@ const (
 	// resources list which can be used as trial template
 	ConfigTrialResources = "trial-resources"
 
+	// EnvTrialName is the env variable of Trial name
+	EnvTrialName = "KATIB_TRIAL_NAME"
+
 	// LabelExperimentName is the label of experiment name.
 	LabelExperimentName = "katib.kubeflow.org/experiment"
 	// LabelSuggestionName is the label of suggestion name.

pkg/webhook/v1beta1/experiment/validator/validator.go

@@ -488,7 +488,7 @@ func (g *DefaultValidator) validateMetricsCollector(inst *experimentsv1beta1.Exp
 	}
 	// TODO(hougangliu): log warning message if some field will not be used for the metricsCollector kind
 	switch mcKind {
-	case commonapiv1beta1.NoneCollector, commonapiv1beta1.StdOutCollector:
+	case commonapiv1beta1.PushCollector, commonapiv1beta1.StdOutCollector:
 		return allErrs
 	case commonapiv1beta1.FileCollector:
 		if mcSpec.Source == nil || mcSpec.Source.FileSystemPath == nil ||

pkg/webhook/v1beta1/pod/inject_webhook.go

@@ -140,15 +140,22 @@ func (s *SidecarInjector) Mutate(pod *v1.Pod, namespace string) (*v1.Pod, error)
 	// Add Katib Trial labels to the Pod metadata.
 	mutatePodMetadata(mutatedPod, trial)
 
+	// Add env variables to the Pod's primary container.
+	// We add this function because of push-based metrics collection function `report_metrics` in Python SDK.
+	// Currently, we only pass the Trial name as env variable `KATIB_TRIAL_NAME` to the training container.
+	if err := mutatePodEnv(mutatedPod, trial); err != nil {
+		return nil, err
+	}
+
 	// Do the following mutation only for the Primary pod.
 	// If PrimaryPodLabel is not set we mutate all pods which are related to Trial job.
 	// Otherwise, mutate pod only with the appropriate labels.
 	if trial.Spec.PrimaryPodLabels != nil && !isPrimaryPod(pod.Labels, trial.Spec.PrimaryPodLabels) {
 		return mutatedPod, nil
 	}
 
-	// If Metrics Collector in None, skip the mutation.
-	if trial.Spec.MetricsCollector.Collector.Kind == common.NoneCollector {
+	// If Metrics Collector is Push, skip the mutation.
+	if trial.Spec.MetricsCollector.Collector.Kind == common.PushCollector {
 		return mutatedPod, nil
 	}
 

pkg/webhook/v1beta1/pod/inject_webhook_test.go

@@ -25,6 +25,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/onsi/gomega"
 	appsv1 "k8s.io/api/apps/v1"
 	batchv1 "k8s.io/api/batch/v1"
@@ -1067,3 +1069,103 @@ func TestMutatePodMetadata(t *testing.T) {
 		}
 	}
 }
+
+func TestMutatePodEnv(t *testing.T) {
+	testcases := map[string]struct {
+		pod        *v1.Pod
+		trial      *trialsv1beta1.Trial
+		mutatedPod *v1.Pod
+		wantError  error
+	}{
+		"Valid case for mutating Pod's env variable": {
+			pod: &v1.Pod{
+				Spec: v1.PodSpec{
+					Containers: []v1.Container{
+						{
+							Name: "training-container",
+						},
+					},
+				},
+			},
+			trial: &trialsv1beta1.Trial{
+				Spec: trialsv1beta1.TrialSpec{
+					PrimaryContainerName: "training-container",
+				},
+			},
+			mutatedPod: &v1.Pod{
+				Spec: v1.PodSpec{
+					Containers: []v1.Container{
+						{
+							Name: "training-container",
+							Env: []v1.EnvVar{
+								{
+									Name: consts.EnvTrialName,
+									ValueFrom: &v1.EnvVarSource{
+										FieldRef: &v1.ObjectFieldSelector{
+											FieldPath: fmt.Sprintf("metadata.labels['%s']", consts.LabelTrialName),
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		"Mismatch for Pod name and primaryContainerName in Trial": {
+			pod: &v1.Pod{
+				Spec: v1.PodSpec{
+					Containers: []v1.Container{
+						{
+							Name: "training-container",
+						},
+					},
+				},
+			},
+			trial: &trialsv1beta1.Trial{
+				Spec: trialsv1beta1.TrialSpec{
+					PrimaryContainerName: "training-containers",
+				},
+			},
+			mutatedPod: &v1.Pod{
+				Spec: v1.PodSpec{
+					Containers: []v1.Container{
+						{
+							Name: "training-container",
+						},
+					},
+				},
+			},
+			wantError: fmt.Errorf(
+				"Unable to find primary container %v in mutated pod containers %v",
+				"training-containers",
+				[]v1.Container{
+					{
+						Name: "training-container",
+					},
+				},
+			),
+		},
+	}
+
+	for name, testcase := range testcases {
+		t.Run(name, func(t *testing.T) {
+			err := mutatePodEnv(testcase.pod, testcase.trial)
+			// Compare error with expected error
+			if testcase.wantError != nil && err != nil {
+				if diff := cmp.Diff(testcase.wantError.Error(), err.Error()); len(diff) != 0 {
+					t.Errorf("Unexpected error (-want,+got):\n%s", diff)
+				}
+			} else if testcase.wantError != nil || err != nil {
+				t.Errorf(
+					"Unexpected error (-want,+got):\n%s",
+					cmp.Diff(testcase.wantError, err, cmpopts.EquateErrors()),
+				)
+			}
+			// Compare Pod with expected pod after mutation
+			if diff := cmp.Diff(testcase.mutatedPod, testcase.pod); len(diff) != 0 {
+				t.Errorf("Unexpected mutated result (-want,+got):\n%s", diff)
+			}
+		})
+	}
+}

pkg/webhook/v1beta1/pod/utils.go

@@ -281,6 +281,33 @@ func mutatePodMetadata(pod *v1.Pod, trial *trialsv1beta1.Trial) {
 	pod.Labels = podLabels
 }
 
+func mutatePodEnv(pod *v1.Pod, trial *trialsv1beta1.Trial) error {
+	// Search for the primary container
+	index := getPrimaryContainerIndex(pod.Spec.Containers, trial.Spec.PrimaryContainerName)
+	if index >= 0 {
+		if pod.Spec.Containers[index].Env == nil {
+			pod.Spec.Containers[index].Env = []v1.EnvVar{}
+		}
+
+		// Pass env variable KATIB_TRIAL_NAME to the primary container using fieldPath
+		pod.Spec.Containers[index].Env = append(
+			pod.Spec.Containers[index].Env,
+			v1.EnvVar{
+				Name: consts.EnvTrialName,
+				ValueFrom: &v1.EnvVarSource{
+					FieldRef: &v1.ObjectFieldSelector{
+						FieldPath: fmt.Sprintf("metadata.labels['%s']", consts.LabelTrialName),
+					},
+				},
+			},
+		)
+		return nil
+	} else {
+		return fmt.Errorf("Unable to find primary container %v in mutated pod containers %v",
+			trial.Spec.PrimaryContainerName, pod.Spec.Containers)
+	}
+}
+
 func getSidecarContainerName(cKind common.CollectorKind) string {
 	if cKind == common.StdOutCollector || cKind == common.FileCollector {
 		return mccommon.MetricLoggerCollectorContainerName

sdk/python/v1beta1/kubeflow/katib/api/katib_client.py

@@ -186,6 +186,7 @@ def tune(
         retain_trials: bool = False,
         packages_to_install: List[str] = None,
         pip_index_url: str = "https://pypi.org/simple",
+        metrics_collector_config: Dict[str, Any] = {"kind": "StdOut"},
     ):
         """Create HyperParameter Tuning Katib Experiment from the objective function.
 
@@ -248,6 +249,9 @@ def tune(
                 to the base image packages. These packages are installed before
                 executing the objective function.
             pip_index_url: The PyPI url from which to install Python packages.
+            metrics_collector_config: Specify the config of metrics collector, 
+                for example, `metrics_collector_config = {"kind": "Push"}`.
+                Currently, we only support `StdOut` and `Push` metrics collector.
 
         Raises:
             ValueError: Function arguments have incorrect type or value.
@@ -380,6 +384,12 @@ def tune(
                         f"Incorrect value for env_per_trial: {env_per_trial}"
                     )
 
+        # Add metrics collector to the Katib Experiment.
+        # Up to now, We only support parameter `kind`, of which default value is `StdOut`, to specify the kind of metrics collector. 
+        experiment.spec.metrics_collector = models.V1beta1MetricsCollectorSpec(
+            collector=models.V1beta1CollectorSpec(kind=metrics_collector_config["kind"])
+        )
+
         # Create Trial specification.
         trial_spec = client.V1Job(
             api_version="batch/v1",