[Improvement] GT-248 restart non-scheduled pod (#1376)

CHANGELOG.md

@@ -29,6 +29,7 @@
 - (Maintenance) Bump K8S Version to 1.24.16
 - (Maintenance) Bump K8S Version to 1.25.12
 - (Maintenance) Bump Go to 1.20.7
+- (Improvement) Remove PodSchedulingFailure condition instead of setting to false, restart pod if it could not be scheduled
 
 ## [1.2.31](https://github.com/arangodb/kube-arangodb/tree/1.2.31) (2023-07-14)
 - (Improvement) Block traffic on the services if there is more than 1 active leader in ActiveFailover mode

docs/generated/actions.md

@@ -36,7 +36,7 @@
 |             JWTRefresh             |    no    |  10m0s  |    no    |    Enterprise Only     |                                     Refresh current JWT secrets on the member                                      |
 |            JWTSetActive            |    no    |  10m0s  |    no    |    Enterprise Only     |                                        Change active JWT key on the cluster                                        |
 |          JWTStatusUpdate           |    no    |  10m0s  |    no    |    Enterprise Only     |                                          Update status of JWT propagation                                          |
-|           KillMemberPod            |    no    |  10m0s  |    no    | Community & Enterprise |                                Execute Delete on Pod 9put pod in Terminating state)                                |
+|           KillMemberPod            |    no    |  10m0s  |    no    | Community & Enterprise |                                Execute Delete on Pod (put pod in Terminating state)                                |
 |             LicenseSet             |    no    |  10m0s  |    no    | Community & Enterprise |                                           Update Cluster license (3.9+)                                            |
 |         MarkToRemoveMember         |    no    |  10m0s  |    no    | Community & Enterprise |               Marks member to be removed. Used when member Pod is annotated with replace annotation                |
 |         MemberPhaseUpdate          |    no    |  10m0s  |    no    | Community & Enterprise |                                                Change member phase                                                 |

internal/actions.yaml

@@ -30,7 +30,10 @@ actions:
     timeout: 30m
     optional: true
   KillMemberPod:
-    description: Execute Delete on Pod 9put pod in Terminating state)
+    description: Execute Delete on Pod (put pod in Terminating state)
+    scopes:
+      - Normal
+      - High
   RotateMember:
     description: Waits for Pod restart and recreation
     timeout: 15m

pkg/apis/deployment/v1/actions.generated.go

@@ -374,7 +374,7 @@ const (
 	// ActionTypeJWTStatusUpdate in scopes Normal. Update status of JWT propagation
 	ActionTypeJWTStatusUpdate ActionType = "JWTStatusUpdate"
 
-	// ActionTypeKillMemberPod in scopes Normal. Execute Delete on Pod 9put pod in Terminating state)
+	// ActionTypeKillMemberPod in scopes High and Normal. Execute Delete on Pod (put pod in Terminating state)
 	ActionTypeKillMemberPod ActionType = "KillMemberPod"
 
 	// ActionTypeLicenseSet in scopes Normal. Update Cluster license (3.9+)
@@ -776,7 +776,7 @@ func (a ActionType) Priority() ActionPriority {
 	case ActionTypeJWTStatusUpdate:
 		return ActionPriorityNormal
 	case ActionTypeKillMemberPod:
-		return ActionPriorityNormal
+		return ActionPriorityHigh
 	case ActionTypeLicenseSet:
 		return ActionPriorityNormal
 	case ActionTypeMarkToRemoveMember:

pkg/apis/deployment/v2alpha1/actions.generated.go

@@ -374,7 +374,7 @@ const (
 	// ActionTypeJWTStatusUpdate in scopes Normal. Update status of JWT propagation
 	ActionTypeJWTStatusUpdate ActionType = "JWTStatusUpdate"
 
-	// ActionTypeKillMemberPod in scopes Normal. Execute Delete on Pod 9put pod in Terminating state)
+	// ActionTypeKillMemberPod in scopes Normal. Execute Delete on Pod (put pod in Terminating state)
 	ActionTypeKillMemberPod ActionType = "KillMemberPod"
 
 	// ActionTypeLicenseSet in scopes Normal. Update Cluster license (3.9+)

pkg/deployment/reconcile/plan_builder_high.go

@@ -54,6 +54,7 @@ func (r *Reconciler) createHighPlan(ctx context.Context, apiObject k8sutil.APIOb
 		ApplyIfEmpty(r.updateMemberUpdateConditionsPlan).
 		ApplyIfEmpty(r.updateMemberRotationConditionsPlan).
 		ApplyIfEmpty(r.createMemberRecreationConditionsPlan).
+		ApplyIfEmpty(r.createMemberPodSchedulingFailurePlan).
 		ApplyIfEmpty(r.createRotateServerStoragePVCPendingResizeConditionPlan).
 		ApplyIfEmpty(r.createChangeMemberArchPlan).
 		ApplyIfEmpty(r.createRotateServerStorageResizePlanRuntime).

pkg/deployment/reconcile/plan_builder_member_pod_scheduling_failure.go

@@ -0,0 +1,122 @@
+//
+// DISCLAIMER
+//
+// Copyright 2023 ArangoDB GmbH, Cologne, Germany
+//
+// 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
+//
+// http://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.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+
+package reconcile
+
+import (
+	"context"
+	"reflect"
+
+	core "k8s.io/api/core/v1"
+
+	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
+	"github.com/arangodb/kube-arangodb/pkg/deployment/actions"
+	"github.com/arangodb/kube-arangodb/pkg/util"
+	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
+)
+
+// createMemberPodSchedulingFailurePlan creates plan actions which are required when
+// some pod has failed to schedule and scheduling parameters already changed
+func (r *Reconciler) createMemberPodSchedulingFailurePlan(ctx context.Context,
+	_ k8sutil.APIObject, spec api.DeploymentSpec, status api.DeploymentStatus, context PlanBuilderContext) api.Plan {
+
+	var p api.Plan
+	if !status.Conditions.IsTrue(api.ConditionTypePodSchedulingFailure) {
+		return p
+	}
+
+	for _, m := range status.Members.AsList() {
+		l := r.log.Str("id", m.Member.ID).Str("role", m.Group.AsRole())
+
+		if m.Member.Phase != api.MemberPhaseCreated || m.Member.Pod.GetName() == "" {
+			// Act only when phase is created
+			continue
+		}
+
+		if m.Member.Conditions.IsTrue(api.ConditionTypeScheduled) || m.Member.Conditions.IsTrue(api.ConditionTypeTerminating) {
+			// Action is needed only for pods which are not scheduled yet
+			continue
+		}
+
+		imageInfo, imageFound := context.SelectImageForMember(spec, status, m.Member)
+		if !imageFound {
+			l.Warn("could not find image for already created member")
+			continue
+		}
+
+		renderedPod, err := context.RenderPodForMember(ctx, context.ACS(), spec, status, m.Member.ID, imageInfo)
+		if err != nil {
+			l.Err(err).Warn("could not render pod for already created member")
+			continue
+		}
+
+		if r.isSchedulingParametersChanged(renderedPod.Spec, m.Member, context) {
+			l.Info("Adding KillMemberPod action: scheduling failed and parameters already updated")
+			p = append(p,
+				actions.NewAction(api.ActionTypeKillMemberPod, m.Group, m.Member, "Scheduling failed"),
+			)
+		}
+	}
+
+	return p
+}
+
+// isSchedulingParametersChanged returns true if parameters related to pod scheduling has changed
+func (r *Reconciler) isSchedulingParametersChanged(expectedSpec core.PodSpec, member api.MemberStatus, context PlanBuilderContext) bool {
+	cache, ok := context.ACS().ClusterCache(member.ClusterID)
+	if !ok {
+		return false
+	}
+	pod, ok := cache.Pod().V1().GetSimple(member.Pod.GetName())
+	if !ok {
+		return false
+	}
+	if r.schedulingParametersAreTheSame(expectedSpec, pod.Spec) {
+		return false
+	}
+	return true
+}
+
+func (r *Reconciler) schedulingParametersAreTheSame(expectedSpec, actualSpec core.PodSpec) bool {
+	if expectedSpec.PriorityClassName != actualSpec.PriorityClassName {
+		return false
+	}
+
+	if !reflect.DeepEqual(expectedSpec.Tolerations, actualSpec.Tolerations) {
+		return false
+	}
+
+	if !reflect.DeepEqual(expectedSpec.NodeSelector, actualSpec.NodeSelector) {
+		return false
+	}
+
+	// we should use SHA256 here because DeepEqual might be unreliable for Affinity rules
+	if specC, err := util.SHA256FromJSON(expectedSpec.Affinity); err != nil {
+		return true
+	} else {
+		if statusC, err := util.SHA256FromJSON(actualSpec.Affinity); err != nil {
+			return true
+		} else if specC != statusC {
+			return false
+		}
+	}
+
+	return true
+}

pkg/deployment/resources/pod_inspector.go

@@ -527,9 +527,7 @@ func (r *Resources) InspectPods(ctx context.Context, cachedStatus inspectorInter
 		}
 	} else if status.Conditions.IsTrue(api.ConditionTypePodSchedulingFailure) &&
 		len(unscheduledPodNames) == 0 {
-		if status.Conditions.Update(api.ConditionTypePodSchedulingFailure, false,
-			"Pods Scheduling Resolved",
-			"No pod reports a scheduling timeout") {
+		if status.Conditions.Remove(api.ConditionTypePodSchedulingFailure) {
 			r.context.CreateEvent(k8sutil.NewPodsSchedulingResolvedEvent(r.context.GetAPIObject()))
 		}
 	}