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/values.yaml.template

@@ -0,0 +1,163 @@
+replicaCount: 1
+
+image:
+  repository: tootsuite/mastodon
+  pullPolicy: Always
+  # https://hub.docker.com/r/tootsuite/mastodon/tags
+  tag: v3.1.4
+  # alternatively, use `latest` for the latest release or `edge` for the image
+  # built from the most recent commit
+  #
+  # tag: latest
+
+ingress:
+  enabled: false
+  annotations:
+    kubernetes.io/ingress.class: nginx
+    kubernetes.io/tls-acme: "true"
+    # cert-manager.io/cluster-issuer: "letsencrypt"
+  # this value is used for LOCAL_DOMAIN
+  hostname: mastodon.local
+  tls:
+    - secretName: mastodon-tls
+      hosts:
+        - mastodon.local
+
+# create an initial administrator user; the password is autogenerated and will
+# have to be reset
+createAdmin:
+  enabled: false
+  username: not_gargron
+  email: not@example.com
+
+# available locales: https://github.com/tootsuite/mastodon/blob/master/config/application.rb#L43
+locale: en
+
+application:
+  web:
+    port: 3000
+  streaming:
+    port: 4000
+    # this should be set manually since os.cpus() returns the number of CPUs on
+    # the node running the pod, which is unrelated to the resources allocated to
+    # the pod by k8s
+    workers: 1
+  sidekiq:
+    concurrency: 25
+
+# these must be set manually; autogenerated keys are rotated on each upgrade
+secrets:
+  secret_key_base: ""
+  otp_secret: ""
+  vapid:
+    private_key: ""
+    public_key: ""
+
+smtp:
+  auth_method: plain
+  ca_file:
+  delivery_method: smtp
+  domain:
+  enable_starttls_auto: true
+  from_address: notifications@example.com
+  login:
+  openssl_verify_mode: peer
+  password:
+  port: 587
+  reply_to:
+  server: smtp.mailgun.org
+  tls: false
+
+# https://github.com/bitnami/charts/tree/master/bitnami/elasticsearch#parameters
+elasticsearch:
+  # `false` will disable full-text search
+  #
+  # if you enable ES after the initial install, you will need to manually run
+  # RAILS_ENV=production bundle exec rake chewy:sync
+  # (https://docs.joinmastodon.org/admin/optional/elasticsearch/)
+  enabled: true
+  # may be removed once https://github.com/tootsuite/mastodon/pull/13828 is part
+  # of a tagged release
+  image:
+    tag: 6
+
+# https://github.com/bitnami/charts/tree/master/bitnami/postgresql#parameters
+postgresql:
+  postgresqlDatabase: mastodon_production
+  # you must set a password; the password generated by the postgresql chart will
+  # be rotated on each upgrade:
+  # https://github.com/bitnami/charts/tree/master/bitnami/postgresql#upgrade
+  postgresqlPassword: ""
+  postgresqlUsername: postgres
+
+# https://github.com/bitnami/charts/tree/master/bitnami/redis#parameters
+redis:
+  # you must set a password; the password generated by the redis chart will be
+  # rotated on each upgrade:
+  password: ""
+
+persistence:
+  assets:
+    # ReadWriteOnce is more widely supported than ReadWriteMany, but limits
+    # scalability, since it requires the Rails and Sidekiq pods to run on the
+    # same node.
+    accessMode: ReadWriteOnce
+    resources:
+      requests:
+        storage: 100Gi
+  system:
+    accessMode: ReadWriteOnce
+    resources:
+      requests:
+        storage: 10Gi
+
+service:
+  type: ClusterIP
+  port: 80
+
+# https://github.com/tootsuite/mastodon/blob/master/Dockerfile#L88
+#
+# if you manually change the UID/GID environment variables, ensure these values
+# match:
+podSecurityContext:
+  runAsUser: 991
+  runAsGroup: 991
+  fsGroup: 991
+
+securityContext: {}
+
+serviceAccount:
+  # Specifies whether a service account should be created
+  create: true
+  # Annotations to add to the service account
+  annotations: {}
+  # The name of the service account to use.
+  # If not set and create is true, a name is generated using the fullname template
+  name: ""
+
+podAnnotations: {}
+
+resources: {}
+  # We usually recommend not to specify default resources and to leave this as a conscious
+  # choice for the user. This also increases chances charts run on environments with little
+  # resources, such as Minikube. If you do want to specify resources, uncomment the following
+  # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
+  # limits:
+  #   cpu: 100m
+  #   memory: 128Mi
+  # requests:
+  #   cpu: 100m
+  #   memory: 128Mi
+
+autoscaling:
+  enabled: false
+  minReplicas: 1
+  maxReplicas: 100
+  targetCPUUtilizationPercentage: 80
+  # targetMemoryUtilizationPercentage: 80
+
+nodeSelector: {}
+
+tolerations: []
+
+affinity: {}