Added NifiNodeGroupAutoscaler with basic scaling strategies

.gitignore

@@ -125,4 +125,6 @@ testbin/*
 
 # editor and IDE paraphernalia
 
-*~
+*~
+
+vendor/

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### Added
 
+- [PR #89](https://github.com/konpyutaika/nifikop/pull/89) - **[Operator/NifiNodeGroupAutoscaler]** Add NifiNodeGroupAutoscaler to automatically horizontally scale a NifiCluster resource via the Kubernetes HorizontalPodAutoscaler.
 - [PR #108](https://github.com/konpyutaika/nifikop/pull/108) - **[Operator/Logging]** Migrated from logr library to zap
 - [PR #112](https://github.com/konpyutaika/nifikop/pull/112) - **[Documentation]** Add section to explain how upgrade from 0.7.6 to 0.8.0.
 - [PR #114](https://github.com/konpyutaika/nifikop/pull/114) - **[Operator/NifiCluster]** Added ability to set the `PodSpec.HostAliases` to provide Pod-level override of hostname resolution when DNS and other options are not applicable.

PROJECT

@@ -1,81 +1,61 @@
 domain: konpyutaika.com
-layout: go.kubebuilder.io/v3
+layout:
+- go.kubebuilder.io/v3
+plugins:
+  manifests.sdk.operatorframework.io/v2: {}
+  scorecard.sdk.operatorframework.io/v2: {}
 projectName: nifikop
 repo: github.com/konpyutaika/nifikop
 resources:
 - api:
     crdVersion: v1
-    # TODO(user): Uncomment the below line if this resource's CRD is namespace scoped, else delete it.
-    # namespaced: true
-  # TODO(user): Uncomment the below line if this resource implements a controller, else delete it.
-  # controller: true
   domain: konpyutaika.com
   group: nifi
   kind: NifiCluster
-  # TODO(user): Update the package path for your API if the below value is incorrect.
   path: github.com/konpyutaika/nifikop/api/v1alpha1
   version: v1alpha1
 - api:
     crdVersion: v1
-    # TODO(user): Uncomment the below line if this resource's CRD is namespace scoped, else delete it.
-    # namespaced: true
-  # TODO(user): Uncomment the below line if this resource implements a controller, else delete it.
-  # controller: true
   domain: konpyutaika.com
   group: nifi
   kind: NifiUserGroup
-  # TODO(user): Update the package path for your API if the below value is incorrect.
   path: github.com/konpyutaika/nifikop/api/v1alpha1
   version: v1alpha1
 - api:
     crdVersion: v1
-    # TODO(user): Uncomment the below line if this resource's CRD is namespace scoped, else delete it.
-    # namespaced: true
-  # TODO(user): Uncomment the below line if this resource implements a controller, else delete it.
-  # controller: true
   domain: konpyutaika.com
   group: nifi
   kind: NifiUser
-  # TODO(user): Update the package path for your API if the below value is incorrect.
   path: github.com/Okonpyutaika/nifikop/api/v1alpha1
   version: v1alpha1
 - api:
     crdVersion: v1
-    # TODO(user): Uncomment the below line if this resource's CRD is namespace scoped, else delete it.
-    # namespaced: true
-  # TODO(user): Uncomment the below line if this resource implements a controller, else delete it.
-  # controller: true
   domain: konpyutaika.com
   group: nifi
   kind: NifiRegistryClient
-  # TODO(user): Update the package path for your API if the below value is incorrect.
   path: github.com/Okonpyutaika/nifikop/api/v1alpha1
   version: v1alpha1
 - api:
     crdVersion: v1
-    # TODO(user): Uncomment the below line if this resource's CRD is namespace scoped, else delete it.
-    # namespaced: true
-  # TODO(user): Uncomment the below line if this resource implements a controller, else delete it.
-  # controller: true
   domain: konpyutaika.com
   group: nifi
   kind: NifiDataflow
-  # TODO(user): Update the package path for your API if the below value is incorrect.
   path: github.com/konpyutaika/nifikop/api/v1alpha1
   version: v1alpha1
 - api:
     crdVersion: v1
-    # TODO(user): Uncomment the below line if this resource's CRD is namespace scoped, else delete it.
-    # namespaced: true
-  # TODO(user): Uncomment the below line if this resource implements a controller, else delete it.
-  # controller: true
   domain: konpyutaika.com
   group: nifi
   kind: NifiParameterContext
-  # TODO(user): Update the package path for your API if the below value is incorrect.
+  path: github.com/konpyutaika/nifikop/api/v1alpha1
+  version: v1alpha1
+- api:
+    crdVersion: v1
+    namespaced: true
+  controller: true
+  domain: konpyutaika.com
+  group: nifi
+  kind: NifiNodeGroupAutoscaler
   path: github.com/konpyutaika/nifikop/api/v1alpha1
   version: v1alpha1
 version: "3"
-plugins:
-  manifests.sdk.operatorframework.io/v2: {}
-  scorecard.sdk.operatorframework.io/v2: {}

api/v1alpha1/common_types.go

@@ -2,6 +2,8 @@ package v1alpha1
 
 import (
 	"fmt"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 // DataflowState defines the state of a NifiDataflow
@@ -25,6 +27,18 @@ type ActionStep string
 // ClusterState holds info about the cluster state
 type ClusterState string
 
+// NodeGroupAutoscalerState holds info autoscaler state
+type NodeGroupAutoscalerState string
+
+// ClusterReplicas holds info about the current number of replicas in the cluster
+type ClusterReplicas int32
+
+// ClusterReplicaSelector holds info about the pod selector for cluster replicas
+type ClusterReplicaSelector string
+
+// ClusterScalingStrategy holds info about how a cluster should be scaled
+type ClusterScalingStrategy string
+
 // ConfigurationState holds info about the configuration state
 type ConfigurationState string
 
@@ -325,6 +339,9 @@ type NodeState struct {
 	InitClusterNode InitClusterNode `json:"initClusterNode"`
 	// PodIsReady whether or not the associated pod is ready
 	PodIsReady bool `json:"podIsReady"`
+	// CreationTime is the time at which this node was created. This must be sortable.
+	// +optional
+	CreationTime metav1.Time `json:"creationTime,omitempty"`
 }
 
 // RackAwarenessState holds info about rack awareness status
@@ -392,6 +409,24 @@ const (
 	NotInitClusterNode InitClusterNode = false
 )
 
+const (
+	// AutoscalerStateOutOfSync describes the status of a NifiNodeGroupAutoscaler as out of sync
+	AutoscalerStateOutOfSync NodeGroupAutoscalerState = "OutOfSync"
+	// AutoscalerStateInSync describes the status of a NifiNodeGroupAutoscaler as in sync
+	AutoscalerStateInSync NodeGroupAutoscalerState = "InSync"
+
+	// upscale strategy representing 'Scale > Disconnect the nodes > Offload data > Reconnect the node' strategy
+	GracefulClusterUpscaleStrategy ClusterScalingStrategy = "graceful"
+	// simply add a node to the cluster and nothing else
+	SimpleClusterUpscaleStrategy ClusterScalingStrategy = "simple"
+	// downscale strategy to remove the last node added
+	LIFOClusterDownscaleStrategy ClusterScalingStrategy = "lifo"
+	// downscale strategy avoiding primary/coordinator nodes
+	NonPrimaryClusterDownscaleStrategy ClusterScalingStrategy = "nonprimary"
+	// downscale strategy targeting nodes which are least busy in terms of # flowfiles in queues
+	LeastBusyClusterDownscaleStrategy ClusterScalingStrategy = "leastbusy"
+)
+
 func ClusterRefsEquals(clusterRefs []ClusterReference) bool {
 	c1 := clusterRefs[0]
 	name := c1.Name

api/v1alpha1/nificluster_types.go

@@ -2,6 +2,8 @@ package v1alpha1
 
 import (
 	"fmt"
+	"sort"
+	"strconv"
 	"strings"
 
 	cmmeta "github.com/jetstack/cert-manager/pkg/apis/meta/v1"
@@ -15,7 +17,7 @@ const (
 	HttpListenerType       = "http"
 	HttpsListenerType      = "https"
 	S2sListenerType        = "s2s"
-	prometheusListenerType = "prometheus"
+	PrometheusListenerType = "prometheus"
 )
 
 // EDIT THIS FILE!  THIS IS SCAFFOLDING FOR YOU TO OWN!
@@ -75,7 +77,7 @@ type NifiClusterSpec struct {
 	// NodeUserIdentityTemplate specifies the template to be used when naming the node user identity (e.g. node-%d-mysuffix)
 	NodeUserIdentityTemplate *string `json:"nodeUserIdentityTemplate,omitempty"`
 	// all node requires an image, unique id, and storageConfigs settings
-	Nodes []Node `json:"nodes"`
+	Nodes []Node `json:"nodes" patchStrategy:"merge" patchMergeKey:"id"`
 	// Defines the configuration for PodDisruptionBudget
 	DisruptionBudget DisruptionBudget `json:"disruptionBudget,omitempty"`
 	// LdapConfiguration specifies the configuration if you want to use LDAP
@@ -161,6 +163,9 @@ type Node struct {
 	ReadOnlyConfig *ReadOnlyConfig `json:"readOnlyConfig,omitempty"`
 	// node configuration
 	NodeConfig *NodeConfig `json:"nodeConfig,omitempty"`
+	// Labels are used to distinguish nodes from one another. They are also used by NifiNodeGroupAutoscaler
+	// to be automatically scaled. See NifiNodeGroupAutoscaler.Spec.NodeLabelsSelector
+	Labels map[string]string `json:"labels,omitempty"`
 }
 
 type ReadOnlyConfig struct {
@@ -726,7 +731,7 @@ func (nProperties NifiProperties) GetAuthorizer() string {
 func (nSpec *NifiClusterSpec) GetMetricPort() *int {
 
 	for _, iListener := range nSpec.ListenersConfig.InternalListeners {
-		if iListener.Type == prometheusListenerType {
+		if iListener.Type == PrometheusListenerType {
 			val := int(iListener.ContainerPort)
 			return &val
 		}
@@ -804,3 +809,46 @@ func (cluster NifiCluster) IsReady() bool {
 func (cluster *NifiCluster) Id() string {
 	return cluster.Name
 }
+
+type Pair struct {
+	Key   string
+	Value metav1.Time
+}
+type PairList []Pair
+
+func (p PairList) Len() int           { return len(p) }
+func (p PairList) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+func (p PairList) Less(i, j int) bool { return p[i].Value.Before(&p[j].Value) }
+
+// Order the nodes in the cluster by the time they were created. The list will be in ascending order.
+// Older nodes will be in the beginning of the list, newer nodes at the end.
+// Nodes for Clusters that existed prior to this feature (v0.11.0+) will not have a creationTime. In this case,
+// LIFO will not be able to reliably determine the oldest node. A rolling restart of nodes in the cluster will
+// resolve this issue going forward.
+func (cluster *NifiCluster) GetCreationTimeOrderedNodes() []Node {
+	nodeIdCreationPairs := PairList{}
+
+	for k, v := range cluster.Status.NodesState {
+		nodeIdCreationPairs = append(nodeIdCreationPairs, Pair{k, v.CreationTime})
+	}
+
+	// nodeIdCreationPairs is now sorted by creation time in ascending order.
+	sort.Sort(nodeIdCreationPairs)
+
+	nodesMap := nodesToIdMap(cluster.Spec.Nodes)
+	timeOrderedNodes := []Node{}
+
+	for _, pair := range nodeIdCreationPairs {
+		id, _ := strconv.Atoi(pair.Key)
+		timeOrderedNodes = append(timeOrderedNodes, nodesMap[int32(id)])
+	}
+	return timeOrderedNodes
+}
+
+func nodesToIdMap(nodes []Node) (nodeMap map[int32]Node) {
+	nodeMap = make(map[int32]Node)
+	for _, node := range nodes {
+		nodeMap[node.Id] = node
+	}
+	return
+}

api/v1alpha1/nificluster_types_test.go

@@ -0,0 +1,46 @@
+package v1alpha1
+
+import (
+	"testing"
+	"time"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestGetCreationTimeOrderedNodes(t *testing.T) {
+	cluster := &NifiCluster{
+		Spec: NifiClusterSpec{
+			Nodes: []Node{
+				{Id: 2, NodeConfigGroup: "scale-group", Labels: map[string]string{"scale_me": "true"}},
+				{Id: 3, NodeConfigGroup: "scale-group", Labels: map[string]string{"scale_me": "true"}},
+				{Id: 4, NodeConfigGroup: "scale-group", Labels: map[string]string{"scale_me": "true"}},
+				{Id: 5, NodeConfigGroup: "other-group", Labels: map[string]string{"other_group": "true"}},
+			},
+		},
+		Status: NifiClusterStatus{
+			NodesState: map[string]NodeState{
+				"2": {
+					CreationTime: v1.NewTime(time.Now().UTC().Add(time.Duration(5) * time.Hour)),
+				},
+				"3": {
+					CreationTime: v1.NewTime(time.Now().UTC().Add(time.Duration(15) * time.Hour)),
+				},
+				"4": {
+					CreationTime: v1.NewTime(time.Now().UTC().Add(time.Duration(10) * time.Hour)),
+				},
+				"5": {
+					CreationTime: v1.NewTime(time.Now().UTC().Add(time.Duration(20) * time.Hour)),
+				},
+			},
+		},
+	}
+
+	nodeList := cluster.GetCreationTimeOrderedNodes()
+
+	if len(nodeList) != 4 {
+		t.Errorf("Incorrect node list: %v+", nodeList)
+	}
+	if nodeList[0].Id != 2 || nodeList[1].Id != 4 || nodeList[2].Id != 3 || nodeList[3].Id != 5 {
+		t.Errorf("Incorrect node list: %v+", nodeList)
+	}
+}