Add Helm chart (#14090)

* add Helm chart

known issues/future work:

- SSO is unsupported

- S3/Minio/GCS is unsupported

- Swift is unsupported

- WEB_DOMAIN is unsupported

- Tor is unsupported

* helm: clarify how LOCAL_DOMAIN is set

* helm: add chart description

* helm: make DB_POOL and Sidekiq concurrency configurable

* helm: only enforce pod affinity when using ReadWriteOnce

* helm: clarify compatibility

* helm: clean up application variables

* helm: add job to create initial admin

chart/templates/deployment-web.yaml

@@ -0,0 +1,101 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: {{ include "mastodon.fullname" . }}-web
+  labels:
+    {{- include "mastodon.labels" . | nindent 4 }}
+spec:
+{{- if not .Values.autoscaling.enabled }}
+  replicas: {{ .Values.replicaCount }}
+{{- end }}
+  selector:
+    matchLabels:
+      {{- include "mastodon.selectorLabels" . | nindent 6 }}
+      component: rails
+  template:
+    metadata:
+    {{- with .Values.podAnnotations }}
+      annotations:
+        {{- toYaml . | nindent 8 }}
+        # roll the pods to pick up any db migrations
+        rollme: {{ randAlphaNum 5 | quote }}
+    {{- end }}
+      labels:
+        {{- include "mastodon.selectorLabels" . | nindent 8 }}
+        component: rails
+    spec:
+      {{- with .Values.imagePullSecrets }}
+      imagePullSecrets:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      serviceAccountName: {{ include "mastodon.serviceAccountName" . }}
+      securityContext:
+        {{- toYaml .Values.podSecurityContext | nindent 8 }}
+      volumes:
+        - name: assets
+          persistentVolumeClaim:
+            claimName: {{ template "mastodon.fullname" . }}-assets
+        - name: system
+          persistentVolumeClaim:
+            claimName: {{ template "mastodon.fullname" . }}-system
+      containers:
+        - name: {{ .Chart.Name }}
+          securityContext:
+            {{- toYaml .Values.securityContext | nindent 12 }}
+          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          command:
+            - bundle
+            - exec
+            - puma
+            - -C
+            - config/puma.rb
+          envFrom:
+            - configMapRef:
+                name: {{ include "mastodon.fullname" . }}-env
+            - secretRef:
+                name: {{ template "mastodon.fullname" . }}
+          env:
+            - name: "DB_PASS"
+              valueFrom:
+                secretKeyRef:
+                  name: {{ .Release.Name }}-postgresql
+                  key: postgresql-password
+            - name: "REDIS_PASSWORD"
+              valueFrom:
+                secretKeyRef:
+                  name: {{ .Release.Name }}-redis
+                  key: redis-password
+            - name: "PORT"
+              value: {{ .Values.application.web.port | quote }}
+          volumeMounts:
+            - name: assets
+              mountPath: /opt/mastodon/public/assets
+            - name: system
+              mountPath: /opt/mastodon/public/system
+          ports:
+            - name: http
+              containerPort: {{ .Values.application.web.port }}
+              protocol: TCP
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: http
+          readinessProbe:
+            httpGet:
+              path: /health
+              port: http
+          resources:
+            {{- toYaml .Values.resources | nindent 12 }}
+      {{- with .Values.nodeSelector }}
+      nodeSelector:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      {{- with .Values.affinity }}
+      affinity:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      {{- with .Values.tolerations }}
+      tolerations:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}