[Feature] Core containers (#871)

CHANGELOG.md

@@ -9,6 +9,7 @@
 - Add debug mode (Golang DLV)
 - License V2 for ArangoDB 3.9.0+
 - Add ArangoClusterSynchronization v1 API
+- Add core containers names to follow their terminations
 
 ## [1.2.6](https://github.com/arangodb/kube-arangodb/tree/1.2.6) (2021-12-15)
 - Add ArangoBackup backoff functionality

pkg/apis/deployment/v1/deployment_spec.go

@@ -17,8 +17,6 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
-// Author Ewout Prangsma
-//
 
 package v1
 
@@ -28,11 +26,12 @@ import (
 	"fmt"
 	"reflect"
 
-	"github.com/arangodb/kube-arangodb/pkg/util/errors"
-
-	"github.com/arangodb/kube-arangodb/pkg/util"
-
 	core "k8s.io/api/core/v1"
+
+	"github.com/arangodb/kube-arangodb/pkg/backup/utils"
+	"github.com/arangodb/kube-arangodb/pkg/util"
+	"github.com/arangodb/kube-arangodb/pkg/util/errors"
+	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 )
 
 var (
@@ -537,3 +536,19 @@ func (s DeploymentSpec) Checksum() (string, error) {
 
 	return fmt.Sprintf("%0x", sha256.Sum256(data)), nil
 }
+
+// GetCoreContainers returns all containers' names which must running in the pod for the given group of servers.
+func (s DeploymentSpec) GetCoreContainers(group ServerGroup) utils.StringList {
+	groupSpec := s.GetServerGroupSpec(group)
+	if len(groupSpec.SidecarCoreNames) == 0 {
+		return utils.StringList{k8sutil.ServerContainerName}
+	}
+
+	result := make(utils.StringList, 0, len(groupSpec.SidecarCoreNames)+1)
+	if !utils.StringList(groupSpec.SidecarCoreNames).Has(k8sutil.ServerContainerName) {
+		result = append(result, k8sutil.ServerContainerName)
+	}
+	result = append(result, groupSpec.SidecarCoreNames...)
+
+	return result
+}

pkg/apis/deployment/v1/deployment_spec_test.go

@@ -17,17 +17,17 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
-// Author Ewout Prangsma
-//
 
 package v1
 
 import (
 	"testing"
 
-	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/stretchr/testify/assert"
 	v1 "k8s.io/api/core/v1"
+
+	"github.com/arangodb/kube-arangodb/pkg/backup/utils"
+	"github.com/arangodb/kube-arangodb/pkg/util"
 )
 
 func TestDeploymentSpecValidate(t *testing.T) {
@@ -122,3 +122,80 @@ func TestDeploymentSpecResetImmutableFields(t *testing.T) {
 		assert.Equal(t, test.Expected, test.Target)
 	}
 }
+
+func TestDeploymentSpec_GetCoreContainers(t *testing.T) {
+	type fields struct {
+		Single       ServerGroupSpec
+		Agents       ServerGroupSpec
+		DBServers    ServerGroupSpec
+		Coordinators ServerGroupSpec
+		SyncMasters  ServerGroupSpec
+		SyncWorkers  ServerGroupSpec
+	}
+
+	type args struct {
+		group ServerGroup
+	}
+
+	tests := map[string]struct {
+		fields fields
+		args   args
+		want   utils.StringList
+	}{
+		"one sidecar container": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: []string{"other"},
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server", "other"},
+		},
+		"one predefined container and one sidecar container": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: []string{"server", "other"},
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server", "other"},
+		},
+		"zero core containers": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: nil,
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server"},
+		},
+		"two non-core containers": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: []string{"other1", "other2"},
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server", "other1", "other2"},
+		},
+	}
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			s := DeploymentSpec{
+				DBServers: test.fields.DBServers,
+			}
+
+			got := s.GetCoreContainers(test.args.group)
+			assert.Equal(t, test.want, got)
+
+		})
+	}
+}

pkg/apis/deployment/v1/deployment_status_members.go

@@ -128,7 +128,8 @@ func (ds DeploymentStatusMembers) ForServerGroup(cb func(group ServerGroup, list
 }
 
 // MemberStatusByPodName returns a reference to the element in the given set of lists that has the given pod name.
-// If no such element exists, nil is returned.
+// Returns member status and group which the pod belong to.
+// If no such element exists, false is returned.
 func (ds DeploymentStatusMembers) MemberStatusByPodName(podName string) (MemberStatus, ServerGroup, bool) {
 	if result, found := ds.Single.ElementByPodName(podName); found {
 		return result, ServerGroupSingle, true

pkg/apis/deployment/v1/server_group_spec.go

@@ -126,6 +126,9 @@ type ServerGroupSpec struct {
 	Affinity *core.PodAffinity `json:"affinity,omitempty"`
 	// NodeAffinity specified additional nodeAffinity settings in ArangoDB Pod definitions
 	NodeAffinity *core.NodeAffinity `json:"nodeAffinity,omitempty"`
+	// SidecarCoreNames is a list of sidecar containers which must run in the pod.
+	// Some names (e.g.: "server", "worker") are reserved, and they don't have any impact.
+	SidecarCoreNames []string `json:"sidecarCoreNames,omitempty"`
 	// Sidecars specifies a list of additional containers to be started
 	Sidecars []core.Container `json:"sidecars,omitempty"`
 	// SecurityContext specifies security context for group

pkg/apis/deployment/v1/zz_generated.deepcopy.go

@@ -1976,6 +1976,11 @@ func (in *ServerGroupSpec) DeepCopyInto(out *ServerGroupSpec) {
 		*out = new(corev1.NodeAffinity)
 		(*in).DeepCopyInto(*out)
 	}
+	if in.SidecarCoreNames != nil {
+		in, out := &in.SidecarCoreNames, &out.SidecarCoreNames
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
 	if in.Sidecars != nil {
 		in, out := &in.Sidecars, &out.Sidecars
 		*out = make([]corev1.Container, len(*in))

pkg/apis/deployment/v2alpha1/deployment_spec.go

@@ -17,8 +17,6 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
-// Author Ewout Prangsma
-//
 
 package v2alpha1
 
@@ -28,11 +26,12 @@ import (
 	"fmt"
 	"reflect"
 
-	"github.com/arangodb/kube-arangodb/pkg/util/errors"
-
-	"github.com/arangodb/kube-arangodb/pkg/util"
-
 	core "k8s.io/api/core/v1"
+
+	"github.com/arangodb/kube-arangodb/pkg/backup/utils"
+	"github.com/arangodb/kube-arangodb/pkg/util"
+	"github.com/arangodb/kube-arangodb/pkg/util/errors"
+	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 )
 
 var (
@@ -537,3 +536,19 @@ func (s DeploymentSpec) Checksum() (string, error) {
 
 	return fmt.Sprintf("%0x", sha256.Sum256(data)), nil
 }
+
+// GetCoreContainers returns all containers' names which must running in the pod for the given group of servers.
+func (s DeploymentSpec) GetCoreContainers(group ServerGroup) utils.StringList {
+	groupSpec := s.GetServerGroupSpec(group)
+	if len(groupSpec.SidecarCoreNames) == 0 {
+		return utils.StringList{k8sutil.ServerContainerName}
+	}
+
+	result := make(utils.StringList, 0, len(groupSpec.SidecarCoreNames)+1)
+	if !utils.StringList(groupSpec.SidecarCoreNames).Has(k8sutil.ServerContainerName) {
+		result = append(result, k8sutil.ServerContainerName)
+	}
+	result = append(result, groupSpec.SidecarCoreNames...)
+
+	return result
+}

pkg/apis/deployment/v2alpha1/deployment_spec_test.go

@@ -17,17 +17,17 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
-// Author Ewout Prangsma
-//
 
 package v2alpha1
 
 import (
 	"testing"
 
-	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/stretchr/testify/assert"
 	v1 "k8s.io/api/core/v1"
+
+	"github.com/arangodb/kube-arangodb/pkg/backup/utils"
+	"github.com/arangodb/kube-arangodb/pkg/util"
 )
 
 func TestDeploymentSpecValidate(t *testing.T) {
@@ -122,3 +122,80 @@ func TestDeploymentSpecResetImmutableFields(t *testing.T) {
 		assert.Equal(t, test.Expected, test.Target)
 	}
 }
+
+func TestDeploymentSpec_GetCoreContainers(t *testing.T) {
+	type fields struct {
+		Single       ServerGroupSpec
+		Agents       ServerGroupSpec
+		DBServers    ServerGroupSpec
+		Coordinators ServerGroupSpec
+		SyncMasters  ServerGroupSpec
+		SyncWorkers  ServerGroupSpec
+	}
+
+	type args struct {
+		group ServerGroup
+	}
+
+	tests := map[string]struct {
+		fields fields
+		args   args
+		want   utils.StringList
+	}{
+		"one sidecar container": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: []string{"other"},
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server", "other"},
+		},
+		"one predefined container and one sidecar container": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: []string{"server", "other"},
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server", "other"},
+		},
+		"zero core containers": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: nil,
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server"},
+		},
+		"two non-core containers": {
+			fields: fields{
+				DBServers: ServerGroupSpec{
+					SidecarCoreNames: []string{"other1", "other2"},
+				},
+			},
+			args: args{
+				group: ServerGroupDBServers,
+			},
+			want: utils.StringList{"server", "other1", "other2"},
+		},
+	}
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			s := DeploymentSpec{
+				DBServers: test.fields.DBServers,
+			}
+
+			got := s.GetCoreContainers(test.args.group)
+			assert.Equal(t, test.want, got)
+
+		})
+	}
+}

pkg/apis/deployment/v2alpha1/deployment_status_members.go

@@ -128,7 +128,8 @@ func (ds DeploymentStatusMembers) ForServerGroup(cb func(group ServerGroup, list
 }
 
 // MemberStatusByPodName returns a reference to the element in the given set of lists that has the given pod name.
-// If no such element exists, nil is returned.
+// Returns member status and group which the pod belong to.
+// If no such element exists, false is returned.
 func (ds DeploymentStatusMembers) MemberStatusByPodName(podName string) (MemberStatus, ServerGroup, bool) {
 	if result, found := ds.Single.ElementByPodName(podName); found {
 		return result, ServerGroupSingle, true

pkg/apis/deployment/v2alpha1/server_group_spec.go

@@ -126,6 +126,9 @@ type ServerGroupSpec struct {
 	Affinity *core.PodAffinity `json:"affinity,omitempty"`
 	// NodeAffinity specified additional nodeAffinity settings in ArangoDB Pod definitions
 	NodeAffinity *core.NodeAffinity `json:"nodeAffinity,omitempty"`
+	// SidecarCoreNames is a list of sidecar containers which must run in the pod.
+	// Some names (e.g.: "server", "worker") are reserved, and they don't have any impact.
+	SidecarCoreNames []string `json:"sidecarCoreNames,omitempty"`
 	// Sidecars specifies a list of additional containers to be started
 	Sidecars []core.Container `json:"sidecars,omitempty"`
 	// SecurityContext specifies security context for group

pkg/apis/deployment/v2alpha1/zz_generated.deepcopy.go

@@ -1976,6 +1976,11 @@ func (in *ServerGroupSpec) DeepCopyInto(out *ServerGroupSpec) {
 		*out = new(v1.NodeAffinity)
 		(*in).DeepCopyInto(*out)
 	}
+	if in.SidecarCoreNames != nil {
+		in, out := &in.SidecarCoreNames, &out.SidecarCoreNames
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
 	if in.Sidecars != nil {
 		in, out := &in.Sidecars, &out.Sidecars
 		*out = make([]v1.Container, len(*in))

pkg/deployment/images.go

@@ -27,18 +27,18 @@ import (
 	"strings"
 	"time"
 
-	"github.com/arangodb/kube-arangodb/pkg/util/globals"
-
 	"github.com/rs/zerolog"
 	core "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
+	"github.com/arangodb/kube-arangodb/pkg/backup/utils"
 	"github.com/arangodb/kube-arangodb/pkg/deployment/pod"
 	"github.com/arangodb/kube-arangodb/pkg/deployment/resources"
 	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
 	"github.com/arangodb/kube-arangodb/pkg/util/constants"
 	"github.com/arangodb/kube-arangodb/pkg/util/errors"
+	"github.com/arangodb/kube-arangodb/pkg/util/globals"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 	inspectorInterface "github.com/arangodb/kube-arangodb/pkg/util/k8sutil/inspector"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil/interfaces"
@@ -141,7 +141,7 @@ func (ib *imagesBuilder) fetchArangoDBImageIDAndVersion(ctx context.Context, cac
 	pod, err := ib.Context.GetCachedStatus().PodReadInterface().Get(ctxChild, podName, metav1.GetOptions{})
 	if err == nil {
 		// Pod found
-		if k8sutil.IsPodFailed(pod) {
+		if k8sutil.IsPodFailed(pod, utils.StringList{k8sutil.ServerContainerName}) {
 			// Wait some time before deleting the pod
 			if time.Now().After(pod.GetCreationTimestamp().Add(30 * time.Second)) {
 				err := globals.GetGlobalTimeouts().Kubernetes().RunWithTimeout(ctx, func(ctxChild context.Context) error {

pkg/deployment/resources/pod_cleanup.go

@@ -17,8 +17,6 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
-// Author Ewout Prangsma
-//
 
 package resources
 
@@ -26,14 +24,13 @@ import (
 	"context"
 	"time"
 
-	"github.com/arangodb/kube-arangodb/pkg/deployment/resources/inspector"
 	v1 "k8s.io/api/core/v1"
 
+	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
+	"github.com/arangodb/kube-arangodb/pkg/deployment/resources/inspector"
 	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 	inspectorInterface "github.com/arangodb/kube-arangodb/pkg/util/k8sutil/inspector"
-
-	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
 )
 
 const (
@@ -55,15 +52,19 @@ func (r *Resources) CleanupTerminatedPods(ctx context.Context, cachedStatus insp
 			return nil
 		}
 
-		if !(k8sutil.IsPodSucceeded(pod) || k8sutil.IsPodFailed(pod) || k8sutil.IsPodTerminating(pod)) {
-			return nil
-		}
-
 		// Find member status
 		memberStatus, group, found := status.Members.MemberStatusByPodName(pod.GetName())
 		if !found {
 			log.Debug().Str("pod", pod.GetName()).Msg("no memberstatus found for pod. Performing cleanup")
 		} else {
+			spec := r.context.GetSpec()
+			coreContainers := spec.GetCoreContainers(group)
+			if !(k8sutil.IsPodSucceeded(pod, coreContainers) || k8sutil.IsPodFailed(pod, coreContainers) ||
+				k8sutil.IsPodTerminating(pod)) {
+				// The pod is not being terminated or failed or succeeded.
+				return nil
+			}
+
 			// Check member termination condition
 			if !memberStatus.Conditions.IsTrue(api.ConditionTypeTerminated) {
 				if !group.IsStateless() {

pkg/deployment/resources/pod_creator_arangod.go

@@ -289,6 +289,10 @@ func (m *MemberArangoDPod) Validate(cachedStatus interfaces.Inspector) error {
 		return err
 	}
 
+	if err := validateSidecars(m.groupSpec.SidecarCoreNames, m.groupSpec.GetSidecars()); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -364,6 +368,7 @@ func (m *MemberArangoDPod) GetSidecars(pod *core.Pod) error {
 	// A sidecar provided by the user
 	sidecars := m.groupSpec.GetSidecars()
 	if len(sidecars) > 0 {
+		addLifecycleSidecar(m.groupSpec.SidecarCoreNames, sidecars)
 		pod.Spec.Containers = append(pod.Spec.Containers, sidecars...)
 	}
 
@@ -634,3 +639,60 @@ func (a *ArangoVersionCheckContainer) GetName() string {
 func (a *ArangoVersionCheckContainer) GetProbes() (*core.Probe, *core.Probe, *core.Probe, error) {
 	return nil, nil, nil, nil
 }
+
+// validateSidecars checks if all core names are in the sidecar list.
+// It returns error when at least one core name is missing.
+func validateSidecars(coreNames []string, sidecars []core.Container) error {
+	for _, coreName := range coreNames {
+		if api.IsReservedServerGroupContainerName(coreName) {
+			return fmt.Errorf("sidecar core name \"%s\" can not be used because it is reserved", coreName)
+		}
+
+		found := false
+		for _, sidecar := range sidecars {
+			if sidecar.Name == coreName {
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			return fmt.Errorf("sidecar core name \"%s\" does not exist on the sidecars' list", coreName)
+		}
+	}
+
+	return nil
+
+}
+
+// addLifecycleSidecar adds lifecycle to all core sidecar unless the sidecar contains its own custom lifecycle.
+func addLifecycleSidecar(coreNames []string, sidecars []core.Container) error {
+	for _, coreName := range coreNames {
+		for i, sidecar := range sidecars {
+			if coreName != sidecar.Name {
+				continue
+			}
+
+			if sidecar.Lifecycle != nil && sidecar.Lifecycle.PreStop != nil {
+				// A user provided a custom lifecycle preStop, so break and check next core name container.
+				break
+			}
+
+			lifecycle, err := k8sutil.NewLifecycleFinalizers()
+			if err != nil {
+				return err
+			}
+
+			if sidecar.Lifecycle == nil {
+				sidecars[i].Lifecycle = lifecycle
+			} else {
+				// Set only preStop, because user can provide postStart lifecycle.
+				sidecars[i].Lifecycle.PreStop = lifecycle.PreStop
+			}
+
+			break
+		}
+	}
+
+	return nil
+}

pkg/deployment/resources/pod_creator_sync.go

@@ -251,6 +251,7 @@ func (m *MemberSyncPod) GetSidecars(pod *core.Pod) error {
 	// A sidecar provided by the user
 	sidecars := m.groupSpec.GetSidecars()
 	if len(sidecars) > 0 {
+		addLifecycleSidecar(m.groupSpec.SidecarCoreNames, sidecars)
 		pod.Spec.Containers = append(pod.Spec.Containers, sidecars...)
 	}
 
@@ -361,6 +362,10 @@ func (m *MemberSyncPod) Init(ctx context.Context, cachedStatus interfaces.Inspec
 }
 
 func (m *MemberSyncPod) Validate(_ interfaces.Inspector) error {
+	if err := validateSidecars(m.groupSpec.SidecarCoreNames, m.groupSpec.GetSidecars()); err != nil {
+		return err
+	}
+
 	return nil
 }
 

pkg/deployment/resources/pod_finalizers.go

@@ -52,6 +52,8 @@ func (r *Resources) runPodFinalizers(ctx context.Context, p *v1.Pod, memberStatu
 	log := r.log.With().Str("pod-name", p.GetName()).Logger()
 	var removalList []string
 
+	// When the main container is terminated, then the whole pod should be terminated,
+	// so sidecar core containers' names should not be checked here.
 	isServerContainerDead := !k8sutil.IsPodServerContainerRunning(p)
 
 	for _, f := range p.ObjectMeta.GetFinalizers() {

pkg/deployment/resources/pod_inspector.go

@@ -96,9 +96,12 @@ func (r *Resources) InspectPods(ctx context.Context, cachedStatus inspectorInter
 			return nil
 		}
 
+		spec := r.context.GetSpec()
+		coreContainers := spec.GetCoreContainers(group)
+
 		// Update state
 		updateMemberStatusNeeded := false
-		if k8sutil.IsPodSucceeded(pod) {
+		if k8sutil.IsPodSucceeded(pod, coreContainers) {
 			// Pod has terminated with exit code 0.
 			wasTerminated := memberStatus.Conditions.IsTrue(api.ConditionTypeTerminated)
 			if memberStatus.Conditions.Update(api.ConditionTypeTerminated, true, "Pod Succeeded", "") {
@@ -112,7 +115,7 @@ func (r *Resources) InspectPods(ctx context.Context, cachedStatus inspectorInter
 					r.InvalidateSyncStatus()
 				}
 			}
-		} else if k8sutil.IsPodFailed(pod) {
+		} else if k8sutil.IsPodFailed(pod, coreContainers) {
 			// Pod has terminated with at least 1 container with a non-zero exit code.
 			wasTerminated := memberStatus.Conditions.IsTrue(api.ConditionTypeTerminated)
 			if memberStatus.Conditions.Update(api.ConditionTypeTerminated, true, "Pod Failed", "") {
@@ -121,11 +124,9 @@ func (r *Resources) InspectPods(ctx context.Context, cachedStatus inspectorInter
 						switch container {
 						case api.ServerGroupReservedInitContainerNameVersionCheck:
 							if c, ok := k8sutil.GetAnyContainerStatusByName(pod.Status.InitContainerStatuses, container); ok {
-								if t := c.State.Terminated; t != nil {
-									if t := c.State.Terminated; t != nil && t.ExitCode == 11 {
-										memberStatus.Upgrade = true
-										updateMemberStatusNeeded = true
-									}
+								if t := c.State.Terminated; t != nil && t.ExitCode == 11 {
+									memberStatus.Upgrade = true
+									updateMemberStatusNeeded = true
 								}
 							}
 						case api.ServerGroupReservedInitContainerNameUpgrade:
@@ -133,20 +134,18 @@ func (r *Resources) InspectPods(ctx context.Context, cachedStatus inspectorInter
 						}
 
 						if c, ok := k8sutil.GetAnyContainerStatusByName(pod.Status.InitContainerStatuses, container); ok {
-							if t := c.State.Terminated; t != nil {
-								if t := c.State.Terminated; t != nil && t.ExitCode != 0 {
-									log.Warn().Str("member", memberStatus.ID).
-										Str("pod", pod.GetName()).
-										Str("container", container).
-										Str("uid", string(pod.GetUID())).
-										Int32("exit-code", t.ExitCode).
-										Str("reason", t.Reason).
-										Str("message", t.Message).
-										Int32("signal", t.Signal).
-										Time("started", t.StartedAt.Time).
-										Time("finished", t.FinishedAt.Time).
-										Msgf("Pod failed in unexpected way: Init Container failed")
-								}
+							if t := c.State.Terminated; t != nil && t.ExitCode != 0 {
+								log.Warn().Str("member", memberStatus.ID).
+									Str("pod", pod.GetName()).
+									Str("container", container).
+									Str("uid", string(pod.GetUID())).
+									Int32("exit-code", t.ExitCode).
+									Str("reason", t.Reason).
+									Str("message", t.Message).
+									Int32("signal", t.Signal).
+									Time("started", t.StartedAt.Time).
+									Time("finished", t.FinishedAt.Time).
+									Msgf("Pod failed in unexpected way: Init Container failed")
 							}
 						}
 					}
@@ -155,20 +154,18 @@ func (r *Resources) InspectPods(ctx context.Context, cachedStatus inspectorInter
 				if containers := k8sutil.GetFailedContainerNames(pod.Status.ContainerStatuses); len(containers) > 0 {
 					for _, container := range containers {
 						if c, ok := k8sutil.GetAnyContainerStatusByName(pod.Status.ContainerStatuses, container); ok {
-							if t := c.State.Terminated; t != nil {
-								if t := c.State.Terminated; t != nil && t.ExitCode != 0 {
-									log.Warn().Str("member", memberStatus.ID).
-										Str("pod", pod.GetName()).
-										Str("container", container).
-										Str("uid", string(pod.GetUID())).
-										Int32("exit-code", t.ExitCode).
-										Str("reason", t.Reason).
-										Str("message", t.Message).
-										Int32("signal", t.Signal).
-										Time("started", t.StartedAt.Time).
-										Time("finished", t.FinishedAt.Time).
-										Msgf("Pod failed in unexpected way: Core Container failed")
-								}
+							if t := c.State.Terminated; t != nil && t.ExitCode != 0 {
+								log.Warn().Str("member", memberStatus.ID).
+									Str("pod", pod.GetName()).
+									Str("container", container).
+									Str("uid", string(pod.GetUID())).
+									Int32("exit-code", t.ExitCode).
+									Str("reason", t.Reason).
+									Str("message", t.Message).
+									Int32("signal", t.Signal).
+									Time("started", t.StartedAt.Time).
+									Time("finished", t.FinishedAt.Time).
+									Msgf("Pod failed in unexpected way: Core Container failed")
 							}
 						}
 					}
@@ -222,7 +219,7 @@ func (r *Resources) InspectPods(ctx context.Context, cachedStatus inspectorInter
 		}
 		// End of Topology labels
 
-		if k8sutil.IsContainerReady(pod, k8sutil.ServerContainerName) {
+		if k8sutil.AreContainersReady(pod, coreContainers) {
 			// Pod is now ready
 			if memberStatus.Conditions.Update(api.ConditionTypeReady, true, "Pod Ready", "") {
 				log.Debug().Str("pod-name", pod.GetName()).Msg("Updating member condition Ready & Initialised to true")

pkg/util/k8sutil/pods.go

@@ -17,9 +17,6 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
-// Author Ewout Prangsma
-// Author Tomasz Mielech
-//
 
 package k8sutil
 
@@ -30,21 +27,17 @@ import (
 	"strings"
 	"time"
 
-	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil/inspector/pod"
-
-	"github.com/arangodb/kube-arangodb/pkg/util"
-
-	"github.com/arangodb/kube-arangodb/pkg/util/errors"
-
-	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil/interfaces"
-
+	core "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/json"
 
-	"k8s.io/apimachinery/pkg/api/resource"
-
-	core "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"github.com/arangodb/kube-arangodb/pkg/backup/utils"
+	"github.com/arangodb/kube-arangodb/pkg/util"
+	"github.com/arangodb/kube-arangodb/pkg/util/errors"
+	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil/inspector/pod"
+	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil/interfaces"
 )
 
 const (
@@ -102,9 +95,10 @@ func IsPodReady(pod *core.Pod) bool {
 	return condition != nil && condition.Status == core.ConditionTrue
 }
 
-// IsContainerReady returns true if the PodReady condition on
-// the given pod is set to true.
-func IsContainerReady(pod *core.Pod, container string) bool {
+// AreContainersReady checks whether Pod is considered as ready.
+// Returns true if the PodReady condition on the given pod is set to true,
+// or all provided containers' names are running and are not in the list of failed containers.
+func AreContainersReady(pod *core.Pod, coreContainers utils.StringList) bool {
 	condition := getPodCondition(&pod.Status, core.PodReady)
 	if condition == nil {
 		return false
@@ -114,21 +108,32 @@ func IsContainerReady(pod *core.Pod, container string) bool {
 		return true
 	}
 
-	if !IsContainerRunning(pod, container) {
-		return false
+	// Check if all required containers are running.
+	for _, c := range coreContainers {
+		if !IsContainerRunning(pod, c) {
+			return false
+		}
 	}
 
+	// From here on all required containers are running, but unready condition must be checked additionally.
 	switch condition.Reason {
 	case ServerContainerConditionContainersNotReady:
-		if strings.HasPrefix(condition.Message, ServerContainerConditionPrefix) {
-			n := strings.TrimPrefix(condition.Message, ServerContainerConditionPrefix)
-
-			return !strings.Contains(n, container)
+		if !strings.HasPrefix(condition.Message, ServerContainerConditionPrefix) {
+			return false
 		}
-		return false
-	default:
-		return false
+
+		unreadyContainers := strings.TrimPrefix(condition.Message, ServerContainerConditionPrefix)
+		for _, c := range coreContainers {
+			if strings.Contains(unreadyContainers, c) {
+				// The container is on the list with unready containers.
+				return false
+			}
+		}
+
+		return true
 	}
+
+	return false
 }
 
 // GetPodByName returns pod if it exists among the pods' list
@@ -163,45 +168,77 @@ func IsContainerRunning(pod *core.Pod, name string) bool {
 	return false
 }
 
-// IsPodSucceeded returns true if the arangodb container of the pod
-// has terminated with exit code 0.
-func IsPodSucceeded(pod *core.Pod) bool {
+// IsPodSucceeded returns true when all core containers are terminated wih a zero exit code,
+// or the whole pod has been succeeded.
+func IsPodSucceeded(pod *core.Pod, coreContainers utils.StringList) bool {
 	if pod.Status.Phase == core.PodSucceeded {
 		return true
-	} else {
-		for _, c := range pod.Status.ContainerStatuses {
-			if c.Name != ServerContainerName {
-				continue
-			}
-
-			t := c.State.Terminated
-			if t != nil {
-				return t.ExitCode == 0
-			}
-		}
-		return false
 	}
+
+	core, succeeded := 0, 0
+	for _, c := range pod.Status.ContainerStatuses {
+		if !coreContainers.Has(c.Name) {
+			// It is not core container, so check next one status.
+			continue
+		}
+
+		core++
+		if t := c.State.Terminated; t != nil && t.ExitCode == 0 {
+			succeeded++
+		}
+	}
+
+	if core > 0 && core == succeeded {
+		// If there are some core containers and all of them succeeded then return that the whole pod succeeded.
+		return true
+	}
+
+	return false
 }
 
-// IsPodFailed returns true if the arangodb container of the pod
-// has terminated wih a non-zero exit code.
-func IsPodFailed(pod *core.Pod) bool {
+// IsPodFailed returns true when one of the core containers is terminated wih a non-zero exit code,
+// or the whole pod has been failed.
+func IsPodFailed(pod *core.Pod, coreContainers utils.StringList) bool {
 	if pod.Status.Phase == core.PodFailed {
 		return true
-	} else {
-		for _, c := range pod.Status.ContainerStatuses {
-			if c.Name != ServerContainerName {
-				continue
-			}
+	}
 
-			t := c.State.Terminated
-			if t != nil {
-				return t.ExitCode != 0
-			}
+	allCore, succeeded, failed := 0, 0, 0
+	for _, c := range pod.Status.ContainerStatuses {
+		if !coreContainers.Has(c.Name) {
+			// It is not core container, so check next one status.
+			continue
 		}
 
+		allCore++
+		if t := c.State.Terminated; t != nil {
+			// A core container is terminated.
+			if t.ExitCode != 0 {
+				failed++
+			} else {
+				succeeded++
+			}
+		}
+	}
+
+	if failed == 0 && succeeded == 0 {
+		// All core containers are not terminated.
 		return false
 	}
+
+	if failed > 0 {
+		// Some (or all) core containers have been terminated.
+		// Some other core containers can be still running or succeeded,
+		// but the whole pod is considered as failed.
+		return true
+	} else if allCore == succeeded {
+		// All core containers are succeeded, so the pod is not failed.
+		// The function `IsPodSucceeded` should recognize it in next iteration.
+		return false
+	}
+
+	// Some core containers are succeeded, but not all of them.
+	return true
 }
 
 // IsContainerFailed returns true if the arangodb container

pkg/util/k8sutil/pods_test.go

@@ -17,8 +17,6 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
-// Author Ewout Prangsma
-//
 
 package k8sutil
 
@@ -27,6 +25,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	v1 "k8s.io/api/core/v1"
+
+	"github.com/arangodb/kube-arangodb/pkg/backup/utils"
 )
 
 // TestIsPodReady tests IsPodReady.
@@ -56,30 +56,265 @@ func TestIsPodReady(t *testing.T) {
 
 // TestIsPodFailed tests IsPodFailed.
 func TestIsPodFailed(t *testing.T) {
-	assert.False(t, IsPodFailed(&v1.Pod{}))
-	assert.False(t, IsPodFailed(&v1.Pod{
-		Status: v1.PodStatus{
-			Phase: v1.PodRunning,
+	type args struct {
+		pod            *v1.Pod
+		coreContainers utils.StringList
+	}
+	tests := map[string]struct {
+		args args
+		want bool
+	}{
+		"empty pod": {
+			args: args{
+				pod: &v1.Pod{},
+			},
 		},
-	}))
-	assert.True(t, IsPodFailed(&v1.Pod{
-		Status: v1.PodStatus{
-			Phase: v1.PodFailed,
+		"pod is running": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						Phase: v1.PodRunning,
+					},
+				},
+			},
 		},
-	}))
+		"pod is failed": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						Phase: v1.PodFailed,
+					},
+				},
+			},
+			want: true,
+		},
+		"one core container failed": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "core_container",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 1,
+									},
+								},
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"something", "core_container"},
+			},
+			want: true,
+		},
+		"one non-core container failed": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "non_core_container",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 1,
+									},
+								},
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"something", "core_container"},
+			},
+		},
+		"one core container succeeded": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "core_container",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"something", "core_container"},
+			},
+		},
+		"first core container succeeded and second is still running": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "core_container1",
+								State: v1.ContainerState{
+									Running: &v1.ContainerStateRunning{},
+								},
+							},
+							{
+								Name: "core_container2",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"core_container1", "core_container2"},
+			},
+			want: true,
+		},
+		"all containers succeeded": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "core_container1",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+							{
+								Name: "core_container2",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"core_container1", "core_container2"},
+			},
+		},
+	}
+
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			got := IsPodFailed(test.args.pod, test.args.coreContainers)
+			assert.Equal(t, test.want, got)
+		})
+	}
 }
 
-// TestIsPodSucceeded tests IsPodSucceeded.
 func TestIsPodSucceeded(t *testing.T) {
-	assert.False(t, IsPodSucceeded(&v1.Pod{}))
-	assert.False(t, IsPodSucceeded(&v1.Pod{
-		Status: v1.PodStatus{
-			Phase: v1.PodRunning,
+	type args struct {
+		pod            *v1.Pod
+		coreContainers utils.StringList
+	}
+	tests := map[string]struct {
+		args args
+		want bool
+	}{
+		"empty pod": {
+			args: args{
+				pod: &v1.Pod{},
+			},
 		},
-	}))
-	assert.True(t, IsPodSucceeded(&v1.Pod{
-		Status: v1.PodStatus{
-			Phase: v1.PodSucceeded,
+		"pod is succeeded": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						Phase: v1.PodSucceeded,
+					},
+				},
+			},
+			want: true,
 		},
-	}))
+		"all core containers succeeded": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "core_container1",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+							{
+								Name: "core_container2",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+							{
+								Name: "non-core_container",
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"core_container1", "core_container2"},
+			},
+			want: true,
+		},
+		"non-core container succeeded": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "core_container1",
+							},
+							{
+								Name: "non-core_container",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"core_container1"},
+			},
+		},
+		"the only one core container succeeded": {
+			args: args{
+				pod: &v1.Pod{
+					Status: v1.PodStatus{
+						ContainerStatuses: []v1.ContainerStatus{
+							{
+								Name: "core_container1",
+								State: v1.ContainerState{
+									Terminated: &v1.ContainerStateTerminated{
+										ExitCode: 0,
+									},
+								},
+							},
+							{
+								Name: "non-core_container",
+							},
+						},
+					},
+				},
+				coreContainers: utils.StringList{"core_container1"},
+			},
+			want: true,
+		},
+	}
+
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			got := IsPodSucceeded(test.args.pod, test.args.coreContainers)
+			assert.Equal(t, test.want, got)
+		})
+	}
 }