Merge pull request #820 from k8up-io/add/container-annotation

adding new annotation to specify in which container inside pod backup should run

cmd/restic/main.go

@@ -46,6 +46,8 @@ var (
 
 			&cli.StringFlag{Destination: &cfg.Config.BackupCommandAnnotation, Name: "backupCommandAnnotation", EnvVars: []string{"BACKUPCOMMAND_ANNOTATION"}, Usage: "Defines the command to invoke when doing a backup via STDOUT."},
 			&cli.StringFlag{Destination: &cfg.Config.BackupFileExtensionAnnotation, Name: "fileExtensionAnnotation", EnvVars: []string{"FILEEXTENSION_ANNOTATION"}, Usage: "Defines the file extension to use for STDOUT backups."},
+			&cli.StringFlag{Destination: &cfg.Config.BackupContainerAnnotation, Name: "backucontainerannotation", EnvVars: []string{"BACKUP_CONTAINERANNOTATION"}, Value: "k8up.io/backupcommand-container", Usage: "set the annotation name that specify the backup container inside the Pod"},
+
 			&cli.StringFlag{Destination: &cfg.Config.PromURL, Name: "promURL", EnvVars: []string{"PROM_URL"}, Usage: "Sets the URL of a prometheus push gateway to report metrics."},
 			&cli.StringFlag{Destination: &cfg.Config.WebhookURL, Name: "webhookURL", Aliases: []string{"statsURL"}, EnvVars: []string{"STATS_URL"}, Usage: "Sets the URL of a server which will retrieve a webhook after the action completes."},
 
@@ -245,7 +247,7 @@ func backupAnnotatedPods(ctx context.Context, resticCLI *resticCli.Restic, mainL
 		return nil
 	}
 
-	podLister := kubernetes.NewPodLister(ctx, cfg.Config.BackupCommandAnnotation, cfg.Config.BackupFileExtensionAnnotation, cfg.Config.Hostname, cfg.Config.TargetPods, mainLogger)
+	podLister := kubernetes.NewPodLister(ctx, cfg.Config.BackupCommandAnnotation, cfg.Config.BackupFileExtensionAnnotation, cfg.Config.BackupContainerAnnotation, cfg.Config.Hostname, cfg.Config.TargetPods, mainLogger)
 	podList, err := podLister.ListPods()
 	if err != nil {
 		mainLogger.Error(err, "could not list pods", "namespace", cfg.Config.Hostname)

docs/modules/ROOT/examples/usage/restic.txt

@@ -18,6 +18,7 @@ OPTIONS:
    --tag value [ --tag value ]                List of tags to consider for given operation
    --backupCommandAnnotation value            Defines the command to invoke when doing a backup via STDOUT. [$BACKUPCOMMAND_ANNOTATION]
    --fileExtensionAnnotation value            Defines the file extension to use for STDOUT backups. [$FILEEXTENSION_ANNOTATION]
+   --backucontainerannotation value           set the annotation name that specify the backup container inside the Pod (default: "k8up.io/backupcommand-container") [$BACKUP_CONTAINERANNOTATION]
    --promURL value                            Sets the URL of a prometheus push gateway to report metrics. [$PROM_URL]
    --webhookURL value, --statsURL value       Sets the URL of a server which will retrieve a webhook after the action completes. [$STATS_URL]
    --backupDir value                          Set from which directory the backup should be performed. (default: "/data") [$BACKUP_DIR]

docs/modules/ROOT/pages/how-tos/application-aware-backups.adoc

@@ -97,3 +97,28 @@ $ ./mongorestore -u root -p <root-pw> mongodb://localhost:27017 --archive=mydata
 2022-02-14T18:07:21.711+0100	79020 document(s) restored successfully. 0 document(s) failed to restore.
 ----
 ====
+
+== Pick a specific container
+
+Using `k8up.io/backupcommand-container` annotation You can specify the container name inside the pod where the command will get executed. 
+
+[source,yaml]
+----
+<SNIP>
+template:
+  metadata:
+    labels:
+      app: my-db
+    annotations:
+      k8up.io/backupcommand: sh -c 'PGDATABASE="$POSTGRES_DB" PGUSER="$POSTGRES_USER" PGPASSWORD="$POSTGRES_PASSWORD" pg_dump --clean'
+      k8up.io/file-extension: .sql
+      k8up.io/backupcommand-container: postgres
+
+  spec:
+    containers:
+      - name: pgbouncer
+      - name: postgres
+      - name: prometheus-exporter
+        ...
+<SNIP>
+----

docs/modules/ROOT/pages/references/annotations.adoc

@@ -30,4 +30,10 @@ See xref:references/operator-config-reference.adoc[Operator Configuration refere
 |A string which is valid file-extension on the source system, e.g. `.sql`.
 |`Pod`
 |`BACKUP_FILEEXTENSIONANNOTATION`
+
+|`k8up.io/backupcommand-container`
+|Specify in which container inside pod backup should be done
+|A string which is valid pod name.
+|`Pod`
+|`BACKUP_CONTAINERANNOTATION`
 |===

e2e/definitions/annotated-subject/deployment.yaml

@@ -16,8 +16,15 @@ spec:
       annotations:
         k8up.io/backupcommand: '/tmp/test.sh'
         k8up.io/file-extension: '.txt'
+        k8up.io/backupcommand-container: subject-container
     spec:
       containers:
+      - image: busybox
+        name: dummy-container-blocking-first-position
+        command:
+        - "/bin/sh"
+        - "-c"
+        - "sleep infinity"
       - name: subject-container
         image: quay.io/prometheus/busybox:latest
         imagePullPolicy: IfNotPresent

e2e/lib/k8up.bash

@@ -129,7 +129,7 @@ given_an_annotated_subject() {
 	export BACKUP_FILE_CONTENT=${2}
 
 	kubectl apply -f definitions/pv/pvc.yaml
-	yq e '.spec.template.spec.containers[0].securityContext.runAsUser='$(id -u)' | .spec.template.spec.containers[0].env[0].value=strenv(BACKUP_FILE_CONTENT) | .spec.template.spec.containers[0].env[1].value=strenv(BACKUP_FILE_NAME)' definitions/annotated-subject/deployment.yaml | kubectl apply -f -
+	yq e '.spec.template.spec.containers[1].securityContext.runAsUser='$(id -u)' | .spec.template.spec.containers[1].env[0].value=strenv(BACKUP_FILE_CONTENT) | .spec.template.spec.containers[1].env[1].value=strenv(BACKUP_FILE_NAME)' definitions/annotated-subject/deployment.yaml | kubectl apply -f -
 
 	echo "✅  The annotated subject is ready"
 }

operator/cfg/config.go

@@ -42,6 +42,7 @@ var (
 type Configuration struct {
 	MountPath                        string
 	BackupAnnotation                 string
+	BackupContainerAnnotation        string
 	BackupCommandAnnotation          string
 	FileExtensionAnnotation          string
 	ServiceAccount                   string

restic/cfg/config.go

@@ -30,6 +30,7 @@ type Configuration struct {
 
 	BackupCommandAnnotation       string
 	BackupFileExtensionAnnotation string
+	BackupContainerAnnotation     string
 	BackupDir                     string
 
 	PromURL    string

restic/kubernetes/pod_exec.go

@@ -23,9 +23,7 @@ type ExecData struct {
 // PodExec sends the command to the specified pod
 // and returns a bytes buffer with the stdout
 func PodExec(pod BackupPod, log logr.Logger) (*ExecData, error) {
-
 	execLogger := log.WithName("k8sExec")
-
 	config, _ := getClientConfig()
 	k8sclient, err := kubernetes.NewForConfig(config)
 	if err != nil {
@@ -44,7 +42,6 @@ func PodExec(pod BackupPod, log logr.Logger) (*ExecData, error) {
 
 	command := qsplit.ToStrings([]byte(pod.Command))
 	execLogger.Info("executing command", "command", strings.Join(command, ", "), "namespace", pod.Namespace, "pod", pod.PodName)
-
 	parameterCodec := runtime.NewParameterCodec(scheme)
 	req.VersionedParams(&apiv1.PodExecOptions{
 		Command:   command,

restic/kubernetes/pod_list.go

@@ -13,14 +13,15 @@ import (
 
 // PodLister holds the state for listing the pods.
 type PodLister struct {
-	backupCommandAnnotation string
-	fileExtensionAnnotation string
-	k8scli                  *kube.Clientset
-	err                     error
-	namespace               string
-	targetPods              map[string]struct{}
-	log                     logr.Logger
-	ctx                     context.Context
+	backupCommandAnnotation   string
+	backupContainerAnnotation string
+	fileExtensionAnnotation   string
+	k8scli                    *kube.Clientset
+	err                       error
+	namespace                 string
+	targetPods                map[string]struct{}
+	log                       logr.Logger
+	ctx                       context.Context
 }
 
 // BackupPod contains all information nessecary to execute the backupcommands.
@@ -33,7 +34,7 @@ type BackupPod struct {
 }
 
 // NewPodLister returns a PodLister configured to find the defined annotations.
-func NewPodLister(ctx context.Context, backupCommandAnnotation, fileExtensionAnnotation, namespace string, targetPods []string, log logr.Logger) *PodLister {
+func NewPodLister(ctx context.Context, backupCommandAnnotation, fileExtensionAnnotation, backupContainerAnnotation, namespace string, targetPods []string, log logr.Logger) *PodLister {
 	k8cli, err := newk8sClient()
 	if err != nil {
 		err = fmt.Errorf("can't create podLister: %v", err)
@@ -45,14 +46,15 @@ func NewPodLister(ctx context.Context, backupCommandAnnotation, fileExtensionAnn
 	}
 
 	return &PodLister{
-		backupCommandAnnotation: backupCommandAnnotation,
-		fileExtensionAnnotation: fileExtensionAnnotation,
-		k8scli:                  k8cli,
-		err:                     err,
-		namespace:               namespace,
-		targetPods:              tp,
-		log:                     log.WithName("k8sClient"),
-		ctx:                     ctx,
+		backupCommandAnnotation:   backupCommandAnnotation,
+		backupContainerAnnotation: backupContainerAnnotation,
+		fileExtensionAnnotation:   fileExtensionAnnotation,
+		k8scli:                    k8cli,
+		err:                       err,
+		namespace:                 namespace,
+		targetPods:                tp,
+		log:                       log.WithName("k8sClient"),
+		ctx:                       ctx,
 	}
 }
 
@@ -72,6 +74,13 @@ func (p *PodLister) ListPods() ([]BackupPod, error) {
 	foundPods := make([]BackupPod, 0)
 	sameOwner := make(map[string]bool)
 	for _, pod := range pods.Items {
+		var execInContainer = pod.Spec.Containers[0].Name
+		annotations := pod.GetAnnotations()
+
+		if execInContainerName, ok := annotations[p.backupContainerAnnotation]; ok {
+			execInContainer = execInContainerName
+		}
+
 		if pod.Status.Phase != corev1.PodRunning {
 			continue
 		}
@@ -83,8 +92,6 @@ func (p *PodLister) ListPods() ([]BackupPod, error) {
 			continue
 		}
 
-		annotations := pod.GetAnnotations()
-
 		if command, ok := annotations[p.backupCommandAnnotation]; ok {
 
 			fileExtension := annotations[p.fileExtensionAnnotation]
@@ -98,7 +105,7 @@ func (p *PodLister) ListPods() ([]BackupPod, error) {
 				foundPods = append(foundPods, BackupPod{
 					Command:       command,
 					PodName:       pod.Name,
-					ContainerName: pod.Spec.Containers[0].Name,
+					ContainerName: execInContainer,
 					Namespace:     p.namespace,
 					FileExtension: fileExtension,
 				})