feat: Add migration

Add the migration feature.

charts/app/templates/migration.yaml

@@ -0,0 +1,38 @@
+{{- if .Values.migrate.enabled -}}
+apiVersion: batch/v1
+kind: Job
+metadata:
+  name: {{ include "app.fullname" . }}-migrate
+  namespace: {{ .Release.Namespace }}
+  labels:
+{{ include "app.labels" . | indent 4 }}
+  annotations:
+    "helm.sh/hook": pre-upgrade
+    "helm.sh/hook-delete-policy": before-hook-creation
+    "helm.sh/hook-weight": "0"
+spec:
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/component: migrate
+{{ include "app.matchLabels" . | indent 8 }}
+    spec:
+      restartPolicy: Never
+    {{- with .Values.imagePullSecrets }}
+      imagePullSecrets:
+        {{- toYaml . | nindent 8 }}
+    {{- end }}
+      containers:
+        - name: {{ .Chart.Name }}
+          command: ["/bin/sh"]
+          args: ["-c", "{{ .Values.migrate.command }}"]
+          image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          envFrom:
+            - secretRef:
+                name: {{ include "app.fullname" $ }}
+        {{ with .Values.env }}
+          env:
+            {{- toYaml . | nindent 12 }}
+        {{- end }}
+{{- end -}}