Add a Helm chart that migrates with a Job and replaces the raw manifest

charts/dynamicweb/Chart.yaml

@@ -0,0 +1,6 @@
+apiVersion: v2
+name: dynamicweb
+description: ungleich dynamicweb (Django CMS) with a Celery worker and Redis
+type: application
+version: 0.1.0
+appVersion: "latest"

charts/dynamicweb/templates/_helpers.tpl

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+{{- define "dw.image" -}}{{ .Values.image.repository }}:{{ .Values.image.tag }}{{- end -}}
+{{- define "dw.pod" -}}
+enableServiceLinks: false   # else a Service named "postgres" injects POSTGRES_PORT=tcp://...
+{{- end -}}

charts/dynamicweb/templates/celery.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata: {name: {{ .Release.Name }}-celery}
+spec:
+  replicas: {{ .Values.celery.replicas }}
+  selector: {matchLabels: {app: {{ .Release.Name }}-celery}}
+  template:
+    metadata: {labels: {app: {{ .Release.Name }}-celery}}
+    spec:
+      {{- include "dw.pod" . | nindent 6 }}
+      containers:
+        - name: celery
+          image: {{ include "dw.image" . }}
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          env: [{name: ROLE, value: celery}]
+          envFrom: [{secretRef: {name: {{ .Values.existingSecret }}}}]

charts/dynamicweb/templates/ingress.yaml

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+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata: {name: {{ .Release.Name }}}
+spec:
+  ingressClassName: {{ .Values.ingress.className }}
+  {{- with .Values.ingress.tlsSecret }}
+  tls: [{secretName: {{ . }}, hosts: {{ $.Values.ingress.hosts | toJson }}}]
+  {{- end }}
+  rules:
+    {{- range .Values.ingress.hosts }}
+    - host: {{ . }}
+      http:
+        paths:
+          - {path: /, pathType: Prefix, backend: {service: {name: {{ $.Release.Name }}-web, port: {number: 80}}}}
+    {{- end }}

charts/dynamicweb/templates/migrate-job.yaml

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+# Runs after the first install and before each upgrade. Web pods don't migrate.
+# (After install it needs Redis, which the app uses while loading, so it waits for it.)
+apiVersion: batch/v1
+kind: Job
+metadata:
+  name: {{ .Release.Name }}-migrate
+  annotations:
+    "helm.sh/hook": post-install,pre-upgrade
+    "helm.sh/hook-delete-policy": before-hook-creation
+spec:
+  backoffLimit: 2
+  template:
+    spec:
+      {{- include "dw.pod" . | nindent 6 }}
+      restartPolicy: Never
+      initContainers:
+        - name: wait-for-redis
+          image: redis:6-alpine
+          command: [sh, -c, "until redis-cli -h redis ping; do sleep 2; done"]
+      containers:
+        - name: migrate
+          image: {{ include "dw.image" . }}
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          env: [{name: ROLE, value: migrate}]
+          envFrom: [{secretRef: {name: {{ .Values.existingSecret }}}}]

charts/dynamicweb/templates/redis.yaml

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+# The app's env points at a Service called "redis" (CELERY_BROKER_URL=redis://redis:6379/0)
+apiVersion: apps/v1
+kind: Deployment
+metadata: {name: redis}
+spec:
+  replicas: 1
+  selector: {matchLabels: {app: redis}}
+  template:
+    metadata: {labels: {app: redis}}
+    spec:
+      containers:
+        - name: redis
+          image: redis:6-alpine
+          ports: [{containerPort: 6379}]
+---
+apiVersion: v1
+kind: Service
+metadata: {name: redis}
+spec:
+  selector: {app: redis}
+  ports: [{port: 6379}]

charts/dynamicweb/templates/web.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata: {name: {{ .Release.Name }}-web}
+spec:
+  replicas: {{ .Values.web.replicas }}
+  selector: {matchLabels: {app: {{ .Release.Name }}-web}}
+  template:
+    metadata: {labels: {app: {{ .Release.Name }}-web}}
+    spec:
+      {{- include "dw.pod" . | nindent 6 }}
+      containers:
+        - name: web
+          image: {{ include "dw.image" . }}
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          env: [{name: RUN_MIGRATIONS, value: "False"}]   # the migrate Job does it
+          envFrom: [{secretRef: {name: {{ .Values.existingSecret }}}}]
+          ports: [{containerPort: 8000}]
+          readinessProbe: {tcpSocket: {port: 8000}, periodSeconds: 10}
+          volumeMounts: [{name: media, mountPath: /usr/src/app/media}]
+      volumes:
+        - name: media
+          persistentVolumeClaim: {claimName: {{ .Release.Name }}-media}
+---
+apiVersion: v1
+kind: Service
+metadata: {name: {{ .Release.Name }}-web}
+spec:
+  selector: {app: {{ .Release.Name }}-web}
+  ports: [{port: 80, targetPort: 8000}]
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata: {name: {{ .Release.Name }}-media}
+spec:
+  accessModes: [{{ .Values.media.accessMode }}]
+  {{- with .Values.media.storageClass }}
+  storageClassName: {{ . }}
+  {{- end }}
+  resources: {requests: {storage: {{ .Values.media.size }}}}

charts/dynamicweb/values.yaml

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+image:
+  repository: REGISTRY/dynamicweb
+  tag: VERSION
+  pullPolicy: IfNotPresent
+
+# Secret holding the app's environment (kubectl create secret generic ... --from-env-file=...)
+# It must exist before the install. See K8S.md.
+existingSecret: dynamicweb
+
+# One host per domain in UNGLEICH_SITE_CONFIGS (add the www. variants)
+ingress:
+  className: nginx
+  hosts: [ungleich.ch, www.ungleich.ch]
+  tlsSecret: ""            # set to enable TLS for the hosts above
+
+web:
+  replicas: 1
+celery:
+  replicas: 1
+
+media:
+  size: 5Gi
+  accessMode: ReadWriteOnce   # ReadWriteMany if web.replicas > 1
+  storageClass: ""

k8s/dynamicweb.yaml

@@ -1,106 +0,0 @@
-# Apply with: kubectl apply -f k8s/dynamicweb.yaml   (see K8S.md)
-# Edit: the image (3 places) and the ingress hosts. Needs the Secret "dynamicweb".
-apiVersion: v1
-kind: PersistentVolumeClaim
-metadata: {name: dynamicweb-media}
-spec:
-  accessModes: [ReadWriteOnce]      # ReadWriteMany if you run more than one web replica
-  resources: {requests: {storage: 5Gi}}
----
-apiVersion: apps/v1
-kind: Deployment
-metadata: {name: redis}
-spec:
-  replicas: 1
-  selector: {matchLabels: {app: redis}}
-  template:
-    metadata: {labels: {app: redis}}
-    spec:
-      containers:
-        - name: redis
-          image: redis:6-alpine
-          ports: [{containerPort: 6379}]
----
-apiVersion: v1
-kind: Service
-metadata: {name: redis}
-spec:
-  selector: {app: redis}
-  ports: [{port: 6379}]
----
-# Run once per release, after the database is restored and before the web pods start.
-apiVersion: batch/v1
-kind: Job
-metadata: {name: dynamicweb-migrate}
-spec:
-  backoffLimit: 2
-  template:
-    spec:
-      enableServiceLinks: false   # else a Service named "postgres" injects POSTGRES_PORT=tcp://...
-      restartPolicy: Never
-      containers:
-        - name: migrate
-          image: REGISTRY/dynamicweb:VERSION
-          env: [{name: ROLE, value: migrate}]
-          envFrom: [{secretRef: {name: dynamicweb}}]
----
-apiVersion: apps/v1
-kind: Deployment
-metadata: {name: dynamicweb-web}
-spec:
-  replicas: 1
-  selector: {matchLabels: {app: dynamicweb-web}}
-  template:
-    metadata: {labels: {app: dynamicweb-web}}
-    spec:
-      enableServiceLinks: false
-      containers:
-        - name: web
-          image: REGISTRY/dynamicweb:VERSION
-          env: [{name: RUN_MIGRATIONS, value: "False"}]   # the migrate Job does it
-          envFrom: [{secretRef: {name: dynamicweb}}]
-          ports: [{containerPort: 8000}]
-          readinessProbe: {tcpSocket: {port: 8000}, periodSeconds: 10}
-          volumeMounts: [{name: media, mountPath: /usr/src/app/media}]
-      volumes:
-        - name: media
-          persistentVolumeClaim: {claimName: dynamicweb-media}
----
-apiVersion: v1
-kind: Service
-metadata: {name: dynamicweb-web}
-spec:
-  selector: {app: dynamicweb-web}
-  ports: [{port: 80, targetPort: 8000}]
----
-apiVersion: apps/v1
-kind: Deployment
-metadata: {name: dynamicweb-celery}
-spec:
-  replicas: 1
-  selector: {matchLabels: {app: dynamicweb-celery}}
-  template:
-    metadata: {labels: {app: dynamicweb-celery}}
-    spec:
-      enableServiceLinks: false
-      containers:
-        - name: celery
-          image: REGISTRY/dynamicweb:VERSION
-          env: [{name: ROLE, value: celery}]
-          envFrom: [{secretRef: {name: dynamicweb}}]
----
-apiVersion: networking.k8s.io/v1
-kind: Ingress
-metadata: {name: dynamicweb}
-spec:
-  ingressClassName: nginx           # your ingress controller
-  # tls: [{secretName: dynamicweb-tls, hosts: [ungleich.ch]}]
-  rules:
-    - host: ungleich.ch             # one rule per domain in UNGLEICH_SITE_CONFIGS
-      http:
-        paths:
-          - {path: /, pathType: Prefix, backend: {service: {name: dynamicweb-web, port: {number: 80}}}}
-    - host: www.ungleich.ch
-      http:
-        paths:
-          - {path: /, pathType: Prefix, backend: {service: {name: dynamicweb-web, port: {number: 80}}}}