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kube-arangodb/pkg/deployment/resources/pod_finalizers.go
2018-06-12 13:30:43 +02:00

236 lines
8.4 KiB
Go

//
// DISCLAIMER
//
// Copyright 2018 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
//
// Author Ewout Prangsma
//
package resources
import (
"context"
"fmt"
"time"
"github.com/rs/zerolog"
"k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"github.com/arangodb/go-driver/agency"
api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1alpha"
"github.com/arangodb/kube-arangodb/pkg/util/constants"
"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
)
// runPodFinalizers goes through the list of pod finalizers to see if they can be removed.
func (r *Resources) runPodFinalizers(ctx context.Context, p *v1.Pod, memberStatus api.MemberStatus, updateMember func(api.MemberStatus) error) error {
log := r.log.With().Str("pod-name", p.GetName()).Logger()
var removalList []string
for _, f := range p.ObjectMeta.GetFinalizers() {
switch f {
case constants.FinalizerPodAgencyServing:
log.Debug().Msg("Inspecting agency-serving finalizer")
if err := r.inspectFinalizerPodAgencyServing(ctx, log, p, memberStatus); err == nil {
removalList = append(removalList, f)
} else {
log.Debug().Err(err).Str("finalizer", f).Msg("Cannot remove finalizer yet")
}
case constants.FinalizerPodDrainDBServer:
log.Debug().Msg("Inspecting drain dbserver finalizer")
if err := r.inspectFinalizerPodDrainDBServer(ctx, log, p, memberStatus, updateMember); err == nil {
removalList = append(removalList, f)
} else {
log.Debug().Err(err).Str("finalizer", f).Msg("Cannot remove finalizer yet")
}
}
}
// Remove finalizers (if needed)
if len(removalList) > 0 {
kubecli := r.context.GetKubeCli()
ignoreNotFound := false
if err := k8sutil.RemovePodFinalizers(log, kubecli, p, removalList, ignoreNotFound); err != nil {
log.Debug().Err(err).Msg("Failed to update pod (to remove finalizers)")
return maskAny(err)
}
}
return nil
}
// inspectFinalizerPodAgencyServing checks the finalizer condition for agency-serving.
// It returns nil if the finalizer can be removed.
func (r *Resources) inspectFinalizerPodAgencyServing(ctx context.Context, log zerolog.Logger, p *v1.Pod, memberStatus api.MemberStatus) error {
// Inspect member phase
if memberStatus.Phase.IsFailed() {
log.Debug().Msg("Pod is already failed, safe to remove agency serving finalizer")
return nil
}
// Inspect deployment deletion state
apiObject := r.context.GetAPIObject()
if apiObject.GetDeletionTimestamp() != nil {
log.Debug().Msg("Entire deployment is being deleted, safe to remove agency serving finalizer")
return nil
}
// Check node the pod is scheduled on
agentDataWillBeGone := false
if p.Spec.NodeName != "" {
node, err := r.context.GetKubeCli().CoreV1().Nodes().Get(p.Spec.NodeName, metav1.GetOptions{})
if err != nil {
log.Warn().Err(err).Msg("Failed to get node for member")
return maskAny(err)
}
if node.Spec.Unschedulable {
agentDataWillBeGone = true
}
}
// Check PVC
pvcs := r.context.GetKubeCli().CoreV1().PersistentVolumeClaims(apiObject.GetNamespace())
pvc, err := pvcs.Get(memberStatus.PersistentVolumeClaimName, metav1.GetOptions{})
if err != nil {
log.Warn().Err(err).Msg("Failed to get PVC for member")
return maskAny(err)
}
if k8sutil.IsPersistentVolumeClaimMarkedForDeletion(pvc) {
agentDataWillBeGone = true
}
// Is this a simple pod restart?
if !agentDataWillBeGone {
log.Debug().Msg("Pod is just being restarted, safe to remove agency serving finalizer")
return nil
}
// Inspect agency state
log.Debug().Msg("Agent data will be gone, so we will check agency serving status first")
ctx = agency.WithAllowNoLeader(ctx) // The ID we're checking may be the leader, so ignore situations where all other agents are followers
ctx, cancel := context.WithTimeout(ctx, time.Second*15) // Force a quick check
defer cancel()
agencyConns, err := r.context.GetAgencyClients(ctx, func(id string) bool { return id != memberStatus.ID })
if err != nil {
log.Debug().Err(err).Msg("Failed to create member client")
return maskAny(err)
}
if len(agencyConns) == 0 {
log.Debug().Err(err).Msg("No more remaining agents, we cannot delete this one")
return maskAny(fmt.Errorf("No more remaining agents"))
}
if err := agency.AreAgentsHealthy(ctx, agencyConns); err != nil {
log.Debug().Err(err).Msg("Remaining agents are not health")
return maskAny(err)
}
// Remaining agents are healthy, we can remove this one and trigger a delete of the PVC
if err := pvcs.Delete(memberStatus.PersistentVolumeClaimName, &metav1.DeleteOptions{}); err != nil {
log.Warn().Err(err).Msg("Failed to delete PVC for member")
return maskAny(err)
}
return nil
}
// inspectFinalizerPodDrainDBServer checks the finalizer condition for drain-dbserver.
// It returns nil if the finalizer can be removed.
func (r *Resources) inspectFinalizerPodDrainDBServer(ctx context.Context, log zerolog.Logger, p *v1.Pod, memberStatus api.MemberStatus, updateMember func(api.MemberStatus) error) error {
// Inspect member phase
if memberStatus.Phase.IsFailed() {
log.Debug().Msg("Pod is already failed, safe to remove drain dbserver finalizer")
return nil
}
// Inspect deployment deletion state
apiObject := r.context.GetAPIObject()
if apiObject.GetDeletionTimestamp() != nil {
log.Debug().Msg("Entire deployment is being deleted, safe to remove drain dbserver finalizer")
return nil
}
// Check node the pod is scheduled on
dbserverDataWillBeGone := false
if p.Spec.NodeName != "" {
node, err := r.context.GetKubeCli().CoreV1().Nodes().Get(p.Spec.NodeName, metav1.GetOptions{})
if err != nil {
log.Warn().Err(err).Msg("Failed to get node for member")
return maskAny(err)
}
if node.Spec.Unschedulable {
dbserverDataWillBeGone = true
}
}
// Check PVC
pvcs := r.context.GetKubeCli().CoreV1().PersistentVolumeClaims(apiObject.GetNamespace())
pvc, err := pvcs.Get(memberStatus.PersistentVolumeClaimName, metav1.GetOptions{})
if err != nil {
log.Warn().Err(err).Msg("Failed to get PVC for member")
return maskAny(err)
}
if k8sutil.IsPersistentVolumeClaimMarkedForDeletion(pvc) {
dbserverDataWillBeGone = true
}
// Is this a simple pod restart?
if !dbserverDataWillBeGone {
log.Debug().Msg("Pod is just being restarted, safe to remove drain dbserver finalizer")
return nil
}
// Inspect cleaned out state
log.Debug().Msg("DBServer data is being deleted, so we will cleanout the dbserver first")
c, err := r.context.GetDatabaseClient(ctx)
if err != nil {
log.Debug().Err(err).Msg("Failed to create member client")
return maskAny(err)
}
cluster, err := c.Cluster(ctx)
if err != nil {
log.Debug().Err(err).Msg("Failed to access cluster")
return maskAny(err)
}
cleanedOut, err := cluster.IsCleanedOut(ctx, memberStatus.ID)
if err != nil {
return maskAny(err)
}
if cleanedOut {
// Cleanout completed
if memberStatus.Conditions.Update(api.ConditionTypeCleanedOut, true, "CleanedOut", "") {
if err := updateMember(memberStatus); err != nil {
return maskAny(err)
}
}
// Trigger PVC removal
if err := pvcs.Delete(memberStatus.PersistentVolumeClaimName, &metav1.DeleteOptions{}); err != nil {
log.Warn().Err(err).Msg("Failed to delete PVC for member")
return maskAny(err)
}
log.Debug().Msg("Server is cleaned out. Save to remove drain dbserver finalizer")
return nil
}
// Not cleaned out yet, check member status
if memberStatus.Conditions.IsTrue(api.ConditionTypeTerminated) {
log.Warn().Msg("Member is already terminated before it could be cleaned out. Not good, but removing drain dbserver finalizer because we cannot do anything further")
return nil
}
// Ensure the cleanout is triggered
log.Debug().Msg("Server is not yet clean out. Triggering a clean out now")
if err := cluster.CleanOutServer(ctx, memberStatus.ID); err != nil {
log.Debug().Err(err).Msg("Failed to clean out server")
return maskAny(err)
}
return maskAny(fmt.Errorf("Server is not yet cleaned out"))
}