I am running a django application in a Kubernetes cluster on gcloud. I implemented the database migration as a helm pre-intall hook that launches my app container and does the database migration. I use cloud-sql-proxy in a sidecar pattern as recommended in the official tutorial: https://cloud.google.com/sql/docs/mysql/connect-kubernetes-engine

Basically this launches my app and a cloud-sql-proxy containers within the pod described by the job. The problem is that cloud-sql-proxy never terminates after my app has completed the migration causing the pre-intall job to timeout and cancel my deployment. How do I gracefully exit the cloud-sql-proxy container after my app container completes so that the job can complete?

Here is my helm pre-intall hook template definition:

apiVersion: batch/v1
kind: Job
metadata:
  name: database-migration-job
  labels:
    app.kubernetes.io/managed-by: {{ .Release.Service | quote }}
    app.kubernetes.io/instance: {{ .Release.Name | quote }}
    app.kubernetes.io/version: {{ .Chart.AppVersion }}
    helm.sh/chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
  annotations:
    # This is what defines this resource as a hook. Without this line, the
    # job is considered part of the release.
    "helm.sh/hook": pre-install,pre-upgrade
    "helm.sh/hook-weight": "-1"
    "helm.sh/hook-delete-policy": hook-succeeded,hook-failed
spec:
  activeDeadlineSeconds: 230
  template:
    metadata:
      name: "{{ .Release.Name }}"
      labels:
        app.kubernetes.io/managed-by: {{ .Release.Service | quote }}
        app.kubernetes.io/instance: {{ .Release.Name | quote }}
        helm.sh/chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
    spec:
      restartPolicy: Never
      containers:
      - name: db-migrate
        image: {{ .Values.my-project.docker_repo }}{{ .Values.backend.image }}:{{ .Values.my-project.image.tag}}
        imagePullPolicy: {{ .Values.my-project.image.pullPolicy }}
        env:
        - name: DJANGO_SETTINGS_MODULE
          value: "{{ .Values.backend.django_settings_module }}"
        - name: SENDGRID_API_KEY
          valueFrom:
            secretKeyRef:
              name: sendgrid-api-key
              key: sendgrid-api-key
        - name: DJANGO_SECRET_KEY
          valueFrom:
            secretKeyRef:
              name: django-secret-key
              key: django-secret-key
        - name: DB_USER
          value: {{ .Values.postgresql.postgresqlUsername }}
        - name: DB_PASSWORD
          {{- if .Values.postgresql.enabled }}
          value: {{ .Values.postgresql.postgresqlPassword }}
          {{- else }}
          valueFrom:
            secretKeyRef:
              name: database-password
              key: database-pwd
          {{- end }}
        - name: DB_NAME
          value: {{ .Values.postgresql.postgresqlDatabase }}
        - name: DB_HOST
          {{- if .Values.postgresql.enabled }}
          value: "postgresql"
          {{- else }}
          value: "127.0.0.1"
          {{- end }}
        workingDir: /app-root
        command: ["/bin/sh"]
        args: ["-c", "python manage.py migrate --no-input"]
      {{- if eq .Values.postgresql.enabled false }}
      - name: cloud-sql-proxy
        image: gcr.io/cloudsql-docker/gce-proxy:1.17
        command:
          - "/cloud_sql_proxy"
          - "-instances=<INSTANCE_CONNECTION_NAME>=tcp:<DB_PORT>"
          - "-credential_file=/secrets/service_account.json"
        securityContext:
          #fsGroup: 65532
          runAsNonRoot: true
          runAsUser: 65532
        volumeMounts:
        - name: db-con-mnt
          mountPath: /secrets/
          readOnly: true
      volumes:
      - name: db-con-mnt
        secret:
          secretName: db-service-account-credentials
      {{- end }}

Funny enough, if I kill the job with "kubectl delete jobs database-migration-job" after the migration is done the helm upgrade completes and my new app version gets installed.