postgres-start-stop-blueprint.yaml

apiVersion: cr.kanister.io/v1alpha1
kind: Blueprint
metadata:
  name: postgres-bp
actions:
  backup:
    kind: StatefulSet
    outputArtifacts:
      cloudObject:
        keyValue:
          backupArtifactLocation: "{{ .Phases.copyFiles.Output.backupArtifactLocation }}"
          backupID: "{{ .Phases.copyFiles.Output.backupID }}"
          backupTag: "{{ .Phases.copyFiles.Output.backupTag }}"
          pvc: '{{- range $key, $_ := index .StatefulSet.PersistentVolumeClaims (index .StatefulSet.Pods 0) -}}{{$key}}{{break}}{{end}}'

    deferPhase:
      func: KubeOps
      args:
        operation: delete
        objectReference:
          apiVersion: v1
          resource: "pods"
          name: "{{ .Phases.createBackupPod.Output.name }}"
          namespace: '{{ .StatefulSet.Namespace }}'

    phases:
    - name: createBackupPod
      func: KubeOps
      objects:
        pgSecret:
          kind: Secret
          name: '{{ index .Object.metadata.labels "app.kubernetes.io/instance" }}-postgresql'
          namespace: '{{ .StatefulSet.Namespace }}'
      args:
        operation: create
        namespace: '{{ .StatefulSet.Namespace }}'
        spec: |-
          apiVersion: v1
          kind: Pod
          metadata:
            generateName: postgres-backup-session
          spec:
            restartPolicy: Never
            containers:
              - name: container
                image: bitnami/postgresql:16
                command:
                - bash
                - -o
                - errexit
                - -o
                - pipefail
                - -c
                - |
                  export PGHOST='{{ index .Object.metadata.labels "app.kubernetes.io/instance" }}-postgresql.{{ .StatefulSet.Namespace }}.svc.cluster.local'
                  export PGUSER='postgres'
                  export PGPASSWORD='{{ index .Phases.createBackupPod.Secrets.pgSecret.Data "postgres-password" | toString }}'
                  ## Create file descriptor to send commands to psql
                  mkfifo /tmp/pg_in
                  ## Create "holder" process to keep pg_in open
                  while sleep 1; do :; done >/tmp/pg_in &
                  ## Save "holder" PID to a file to kill it later
                  echo $! > /tmp/holder_pid
                  ## Run psql session reading from pg_in and writing ot pg_out
                  ## Using tee here to keep the pod logs (might need to replace with just `> /tmp/pg_out`)
                  ## TODO: should we track stderr here?
                  cat /tmp/pg_in | psql -U ${PGUSER} | tee /tmp/pg_out

    - func: WaitV2
      name: waitForPodReady
      args:
        timeout: 5m
        conditions:
          anyOf:
          - condition: '{{ $available := false }}{{ range $condition := $.status.conditions }}{{ if and (eq .type "ContainersReady") (eq .status "True") }}{{ $available = true }}{{ end }}{{ end }}{{ $available }}'
            objectReference:
              apiVersion: "v1"
              name: "{{ .Phases.createBackupPod.Output.name }}"
              namespace: '{{ .StatefulSet.Namespace }}'
              resource: "pods"

    - name: startBackup
      func: KubeExec
      args:
        namespace: '{{ .StatefulSet.Namespace }}'
        pod: "{{ .Phases.createBackupPod.Output.name }}"
        command:
        - bash
        - -o
        - errexit
        - -o
        - pipefail
        - -c
        - |
          ## Send pg_backup_start command to psql session
          echo "SELECT pg_backup_start(label => 'kanister_backup', fast => false);" > /tmp/pg_in
          ## Make sure operation completed
          ## TODO: maybe there's a better way to fail/log here?
          grep -q pg_backup_start <(tail -f /tmp/pg_out)

    - name: copyFiles
      func: CopyVolumeData
      args:
        namespace: '{{ .StatefulSet.Namespace }}'
        ## TODO: maybe there's a better way of doing that in go templates
        volume: '{{- range $key, $_ := index .StatefulSet.PersistentVolumeClaims (index .StatefulSet.Pods 0) -}}{{$key}}{{break}}{{end}}'
        # volume: '{{ index .StatefulSet.PersistentVolumeClaims 0 }}'
        dataArtifactPrefix: s3-bucket/path/artifactPrefix

    - name: stopBackup
      func: KubeExec
      args:
        namespace: '{{ .StatefulSet.Namespace }}'
        pod: "{{ .Phases.createBackupPod.Output.name }}"
        command:
        - bash
        - -o
        - errexit
        - -o
        - pipefail
        - -c
        - |
          ## Send pg_backup_stop command to psql session
          echo "SELECT * FROM pg_backup_stop(wait_for_archive => true);" > /tmp/pg_in
          ## Make sure operation completed
          ## TODO: maybe there's a better way to fail/log here?
          grep -q "LABEL: kanister_backup" <(tail -f /tmp/pg_out)

  restore:
    kind: StatefulSet
    inputArtifactNames:
    - cloudObject
    phases:
    - func: ScaleWorkload
      name: ShutdownApplication
      args:
        namespace: '{{.StatefulSet.Namespace }}'
        name: '{{ .StatefulSet.Name }}'
        kind: StatefulSet
        replicas: 0

    - func: RestoreData
      name: RestoreFromObjectStore
      args:
        namespace: '{{.StatefulSet.Namespace }}'
        # pod: '{{ index .StatefulSet.Pods 0 }}'
        volumes:
          '{{ .ArtifactsIn.cloudObject.KeyValue.pvc }}': '/mnt/vol_data/{{ .ArtifactsIn.cloudObject.KeyValue.pvc }}'

        image: ghcr.io/kanisterio/kanister-tools:0.110.0
        backupArtifactPrefix: s3-bucket/path/artifactPrefix
        backupTag: '{{ .ArtifactsIn.cloudObject.KeyValue.backupTag }}'

    deferPhase:
      func: ScaleWorkload
      name: StartupApplication
      args:
        namespace: '{{.StatefulSet.Namespace }}'
        name: '{{ .StatefulSet.Name }}'
        kind: StatefulSet
        replicas: '{{ len .StatefulSet.Pods }}'

  delete:
    inputArtifactNames:
      - cloudObject
    phases:
    - func: DeleteData
      name: deleteFromObjectStore
      args:
        namespace: '{{.StatefulSet.Namespace }}'
        backupArtifactPrefix: s3-bucket/path/artifactPrefix
        backupID: "{{ .ArtifactsIn.cloudObject.KeyValue.backupID }}"