[Feature] Allow to specify initContainers

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [master](https://github.com/arangodb/kube-arangodb/tree/master) (N/A)
 - Allow to mount EmptyDir
+- Allow to specify initContainers in pods
 
 ## [1.1.0](https://github.com/arangodb/kube-arangodb/tree/master) (2020-10-14)
 - Change NumberOfCores and MemoryOverride flags to be set to true by default

pkg/apis/deployment/v1/deployment.go

@@ -24,37 +24,37 @@ package v1
 
 import (
 	"github.com/arangodb/kube-arangodb/pkg/apis/deployment"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	meta "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // ArangoDeploymentList is a list of ArangoDB clusters.
 type ArangoDeploymentList struct {
-	metav1.TypeMeta `json:",inline"`
+	meta.TypeMeta `json:",inline"`
 	// Standard list metadata
 	// More info: http://releases.k8s.io/HEAD/docs/devel/api-conventions.md#metadata
-	metav1.ListMeta `json:"metadata,omitempty"`
-	Items           []ArangoDeployment `json:"items"`
+	meta.ListMeta `json:"metadata,omitempty"`
+	Items         []ArangoDeployment `json:"items"`
 }
 
 // +genclient
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // ArangoDeployment contains the entire Kubernetes info for an ArangoDB database deployment.
 type ArangoDeployment struct {
-	metav1.TypeMeta   `json:",inline"`
-	metav1.ObjectMeta `json:"metadata,omitempty"`
-	Spec              DeploymentSpec   `json:"spec,omitempty"`
-	Status            DeploymentStatus `json:"status,omitempty"`
+	meta.TypeMeta   `json:",inline"`
+	meta.ObjectMeta `json:"metadata,omitempty"`
+	Spec            DeploymentSpec   `json:"spec,omitempty"`
+	Status          DeploymentStatus `json:"status,omitempty"`
 }
 
 type ServerGroupFunc func(ServerGroup, ServerGroupSpec, *MemberStatusList) error
 
 // AsOwner creates an OwnerReference for the given deployment
-func (d *ArangoDeployment) AsOwner() metav1.OwnerReference {
+func (d *ArangoDeployment) AsOwner() meta.OwnerReference {
 	trueVar := true
-	return metav1.OwnerReference{
+	return meta.OwnerReference{
 		APIVersion: SchemeGroupVersion.String(),
 		Kind:       deployment.ArangoDeploymentResourceKind,
 		Name:       d.Name,

pkg/apis/deployment/v1/deployment_spec.go

@@ -30,7 +30,7 @@ import (
 
 	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/pkg/errors"
-	v1 "k8s.io/api/core/v1"
+	core "k8s.io/api/core/v1"
 )
 
 var (
@@ -39,9 +39,9 @@ var (
 
 // validatePullPolicy the image pull policy.
 // Return errors when validation fails, nil on success.
-func validatePullPolicy(v v1.PullPolicy) error {
+func validatePullPolicy(v core.PullPolicy) error {
 	switch v {
-	case "", v1.PullAlways, v1.PullNever, v1.PullIfNotPresent:
+	case "", core.PullAlways, core.PullNever, core.PullIfNotPresent:
 		return nil
 	default:
 		return maskAny(errors.Wrapf(ValidationError, "Unknown pull policy: '%s'", string(v)))
@@ -54,7 +54,7 @@ type DeploymentSpec struct {
 	Environment        *Environment                      `json:"environment,omitempty"`
 	StorageEngine      *StorageEngine                    `json:"storageEngine,omitempty"`
 	Image              *string                           `json:"image,omitempty"`
-	ImagePullPolicy    *v1.PullPolicy                    `json:"imagePullPolicy,omitempty"`
+	ImagePullPolicy    *core.PullPolicy                  `json:"imagePullPolicy,omitempty"`
 	ImagePullSecrets   []string                          `json:"imagePullSecrets,omitempty"`
 	ImageDiscoveryMode *DeploymentImageDiscoveryModeSpec `json:"imageDiscoveryMode,omitempty"`
 	DowntimeAllowed    *bool                             `json:"downtimeAllowed,omitempty"`
@@ -161,7 +161,7 @@ func (s DeploymentSpec) GetSyncImage() string {
 }
 
 // GetImagePullPolicy returns the value of imagePullPolicy.
-func (s DeploymentSpec) GetImagePullPolicy() v1.PullPolicy {
+func (s DeploymentSpec) GetImagePullPolicy() core.PullPolicy {
 	return util.PullPolicyOrDefault(s.ImagePullPolicy)
 }
 
@@ -253,7 +253,7 @@ func (s *DeploymentSpec) SetDefaults(deploymentName string) {
 		s.Image = util.NewString(DefaultImage)
 	}
 	if s.GetImagePullPolicy() == "" {
-		s.ImagePullPolicy = util.NewPullPolicy(v1.PullIfNotPresent)
+		s.ImagePullPolicy = util.NewPullPolicy(core.PullIfNotPresent)
 	}
 	s.ExternalAccess.SetDefaults()
 	s.RocksDB.SetDefaults()

pkg/apis/deployment/v1/server_group.go

@@ -27,27 +27,30 @@ import "time"
 type ServerGroup int
 
 const (
-	ServerGroupUnknown      ServerGroup = 0
-	ServerGroupSingle       ServerGroup = 1
-	ServerGroupAgents       ServerGroup = 2
-	ServerGroupDBServers    ServerGroup = 3
-	ServerGroupCoordinators ServerGroup = 4
-	ServerGroupSyncMasters  ServerGroup = 5
-	ServerGroupSyncWorkers  ServerGroup = 6
-
-	ServerGroupSingleString       = "single"
-	ServerGroupAgentsString       = "agent"
-	ServerGroupDBServersString    = "dbserver"
-	ServerGroupCoordinatorsString = "coordinator"
-	ServerGroupSyncMastersString  = "syncmaster"
-	ServerGroupSyncWorkersString  = "syncworker"
-
-	ServerGroupSingleAbbreviatedString       = "sngl"
-	ServerGroupAgentsAbbreviatedString       = "agnt"
-	ServerGroupDBServersAbbreviatedString    = "prmr"
-	ServerGroupCoordinatorsAbbreviatedString = "crdn"
-	ServerGroupSyncMastersAbbreviatedString  = "syma"
-	ServerGroupSyncWorkersAbbreviatedString  = "sywo"
+	ServerGroupUnknown        ServerGroup = 0
+	ServerGroupSingle         ServerGroup = 1
+	ServerGroupAgents         ServerGroup = 2
+	ServerGroupDBServers      ServerGroup = 3
+	ServerGroupCoordinators   ServerGroup = 4
+	ServerGroupSyncMasters    ServerGroup = 5
+	ServerGroupSyncWorkers    ServerGroup = 6
+	ServerGroupImageDiscovery ServerGroup = -1
+
+	ServerGroupSingleString         = "single"
+	ServerGroupAgentsString         = "agent"
+	ServerGroupDBServersString      = "dbserver"
+	ServerGroupCoordinatorsString   = "coordinator"
+	ServerGroupSyncMastersString    = "syncmaster"
+	ServerGroupSyncWorkersString    = "syncworker"
+	ServerGroupImageDiscoveryString = "imagediscovery"
+
+	ServerGroupSingleAbbreviatedString         = "sngl"
+	ServerGroupAgentsAbbreviatedString         = "agnt"
+	ServerGroupDBServersAbbreviatedString      = "prmr"
+	ServerGroupCoordinatorsAbbreviatedString   = "crdn"
+	ServerGroupSyncMastersAbbreviatedString    = "syma"
+	ServerGroupSyncWorkersAbbreviatedString    = "sywo"
+	ServerGroupImageDiscoveryAbbreviatedString = "id"
 )
 
 var (

pkg/apis/deployment/v1/server_group_init_containers.go

@@ -0,0 +1,127 @@
+//
+// DISCLAIMER
+//
+// Copyright 2020 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 Adam Janikowski
+//
+
+package v1
+
+import (
+	"github.com/arangodb/kube-arangodb/pkg/apis/shared"
+	sharedv1 "github.com/arangodb/kube-arangodb/pkg/apis/shared/v1"
+	"github.com/pkg/errors"
+	core "k8s.io/api/core/v1"
+)
+
+const (
+	ServerGroupReservedInitContainerNameLifecycle = "init-lifecycle"
+	ServerGroupReservedInitContainerNameUUID      = "uuid"
+)
+
+func IsReservedServerGroupInitContainerName(name string) bool {
+	switch name {
+	case ServerGroupReservedInitContainerNameLifecycle, ServerGroupReservedInitContainerNameUUID:
+		return true
+	default:
+		return false
+	}
+}
+
+func ValidateServerGroupInitContainerName(name string) error {
+	if IsReservedServerGroupInitContainerName(name) {
+		return errors.Errorf("InitContainer name %s is restricted", name)
+	}
+
+	return sharedv1.AsKubernetesResourceName(&name).Validate()
+}
+
+type ServerGroupInitContainerMode string
+
+func (s *ServerGroupInitContainerMode) Get() ServerGroupInitContainerMode {
+	if s == nil {
+		return ServerGroupInitContainerUpdateMode // default
+	}
+
+	return *s
+}
+
+func (s ServerGroupInitContainerMode) New() *ServerGroupInitContainerMode {
+	return &s
+}
+
+func (s *ServerGroupInitContainerMode) Validate() error {
+	switch v := s.Get(); v {
+	case ServerGroupInitContainerIgnoreMode, ServerGroupInitContainerUpdateMode:
+		return nil
+	default:
+		return errors.Errorf("Unknown serverGroupInitContainerMode %s", v)
+	}
+}
+
+const (
+	// ServerGroupInitContainerIgnoreMode ignores init container changes in pod recreation flow
+	ServerGroupInitContainerIgnoreMode ServerGroupInitContainerMode = "ignore"
+	// ServerGroupInitContainerUpdateMode enforce update of pod if init container has been changed
+	ServerGroupInitContainerUpdateMode ServerGroupInitContainerMode = "update"
+)
+
+type ServerGroupInitContainers struct {
+	// Containers contains list of containers
+	Containers []core.Container `json:"containers,omitempty"`
+
+	// Mode keep container replace mode
+	Mode *ServerGroupInitContainerMode `json:"mode,omitempty"`
+}
+
+func (s *ServerGroupInitContainers) GetMode() *ServerGroupInitContainerMode {
+	if s == nil {
+		return nil
+	}
+
+	return s.Mode
+}
+
+func (s *ServerGroupInitContainers) GetContainers() []core.Container {
+	if s == nil {
+		return nil
+	}
+
+	return s.Containers
+}
+
+func (s *ServerGroupInitContainers) Validate() error {
+	if s == nil {
+		return nil
+	}
+
+	return shared.WithErrors(
+		shared.PrefixResourceError("mode", s.Mode.Validate()),
+		shared.PrefixResourceError("containers", s.validateInitContainers()),
+	)
+}
+
+func (s *ServerGroupInitContainers) validateInitContainers() error {
+	for _, c := range s.Containers {
+		if err := ValidateServerGroupInitContainerName(c.Name); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

pkg/apis/deployment/v1/server_group_spec.go

@@ -100,6 +100,8 @@ type ServerGroupSpec struct {
 	VolumeMounts ServerGroupSpecVolumeMounts `json:"volumeMounts,omitempty"`
 	// ExtendedRotationCheck extend checks for rotation
 	ExtendedRotationCheck *bool `json:"extendedRotationCheck,omitempty"`
+	// InitContainers Init containers specification
+	InitContainers *ServerGroupInitContainers `json:"initContainers,omitempty"`
 }
 
 // ServerGroupSpecSecurityContext contains specification for pod security context
@@ -471,6 +473,7 @@ func (s *ServerGroupSpec) validate() error {
 	return shared.WithErrors(
 		shared.PrefixResourceError("volumes", s.Volumes.Validate()),
 		shared.PrefixResourceError("volumeMounts", s.VolumeMounts.Validate()),
+		shared.PrefixResourceError("initContainers", s.InitContainers.Validate()),
 		s.validateVolumes(),
 	)
 }
@@ -482,12 +485,30 @@ func (s *ServerGroupSpec) validateVolumes() error {
 		volumes[volume.Name] = true
 	}
 
+	volumes["arangod-data"] = true
+
 	for _, mount := range s.VolumeMounts {
 		if _, ok := volumes[mount.Name]; !ok {
 			return errors.Errorf("Volume %s is not defined, but required by mount", mount.Name)
 		}
 	}
 
+	for _, container := range s.InitContainers.GetContainers() {
+		for _, mount := range container.VolumeMounts {
+			if _, ok := volumes[mount.Name]; !ok {
+				return errors.Errorf("Volume %s is not defined, but required by mount in init container %s", mount.Name, container.Name)
+			}
+		}
+	}
+
+	for _, container := range s.Sidecars {
+		for _, mount := range s.VolumeMounts {
+			if _, ok := volumes[mount.Name]; !ok {
+				return errors.Errorf("Volume %s is not defined, but required by mount in sidecar %s", mount.Name, container.Name)
+			}
+		}
+	}
+
 	return nil
 }
 

pkg/deployment/images.go

@@ -218,7 +218,7 @@ func (ib *imagesBuilder) fetchArangoDBImageIDAndVersion(ctx context.Context, ima
 		return true, maskAny(err)
 	}
 
-	if _, _, err := resources.CreateArangoPod(ib.KubeCli, ib.APIObject, pod); err != nil {
+	if _, err := resources.CreateArangoPod(ib.KubeCli, ib.APIObject, ib.Spec, api.ServerGroupImageDiscovery, pod); err != nil {
 		log.Debug().Err(err).Msg("Failed to create image ID pod")
 		return true, maskAny(err)
 	}