charts/bitnami/discourse

Discourse

Discourse is an open source discussion platform. It can be used as a mailing list, discussion forum, long-form chat room, and more.

TL;DR;

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/discourse

Introduction

This chart bootstraps a Discourse deployment on a Kubernetes cluster using the Helm package manager.

It also packages Bitnami Postgresql and Bitnami Redis which are required as databases for the Discourse application.

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters.

Prerequisites

• Kubernetes 1.12+
• Helm 2.11+ or Helm 3.0-beta3+
• PV provisioner support in the underlying infrastructure
• ReadWriteMany volumes for deployment scaling

Installing the Chart

To install the chart with the release name my-release:

$ helm install my-release bitnami/discourse

The command deploys Discourse on the Kubernetes cluster in the default configuration. The Parameters section lists the parameters that can be configured during installation.

Tip

: List all releases using helm list

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

Parameters

The following table lists the configurable parameters of the Discourse chart and their default values.

Parameter	Description	Default
global.imageRegistry	Global Docker image registry	nil
global.imagePullSecrets	Global Docker registry secret names as an array	[] (does not add image pull secrets to deployed pods)
global.storageClass	Global storage class for dynamic provisioning	nil

Common parameters

Parameter	Description	Default
replicaCount	Number of Discourse & Sidekiq replicas	1
image.registry	Discourse image registry	docker.io
image.repository	Discourse image name	bitnami/discouse
image.tag	Discourse image tag	{TAG_NAME}
image.pullPolicy	Discourse image pull policy	IfNotPresent
image.debug	Specify if debug logs should be enabled	false
imagePullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
nameOverride	String to partially override discourse.fullname	nil
fullnameOverride	String to fully override discourse.fullname	nil
extraVolumes	Array of extra volumes to be added deployment. Requires setting extraVolumeMounts	[] (evaluated as a template)
sidecars	Attach additional sidecar containers to the pod	[] (evaluated as a template)
initContainers	Additional init containers to add to the pods	[] (evaluated as a template)
serviceAccount.create	Whether the service account should be created	false
serviceAccount.annotations	Annotations to add to the service account	{}
serviceAccount.name	Name to be used for the service account	""
podSecurityContext	Pod security context specification	{}
persistence.enabled	Whether to enable persistence based on Persistent Volume Claims	true
persistence.storageClass	PVC Storage Class	nil
persistence.existingClaim	Name of an existing PVC to reuse	nil
persistence.accessMode	PVC Access Mode (RWO, ROX, RWX)	ReadWriteOnce
persistence.size	Size of the PVC to request	10Gi
podAnnotations	Additional pod annotations	{}
podLabels	Additional pod labels	{} (evaluated as a template)
commonLabels	Labels to be added to all deployed resources	{} (evaluated as a template)
commonAnnotations	Annotations to be added to all deployed resources	{} (evaluated as a template)
nodeSelector	Node labels for pod assignment.	{} (evaluated as a template)
tolerations	Tolerations for pod assignment.	[] (evaluated as a template)
affinity	Affinity for pod assignment	{} (evaluated as a template)

Service parameters

Parameter	Description	Default
service.type	Kubernetes Service type	LoadBalancer
service.port	Service HTTP port	80
service.nodePort	NodePort service IP address	nil
service.loadBalancerIP	LoadBalancer service IP address	nil
service.externalTrafficPolicy	Enable client source IP preservation	Cluster
service.annotations	Service annotations	{} (evaluated as a template)
service.loadBalancerSourceRanges	Restricts access for LoadBalancer (only with service.type: LoadBalancer)	[]
service.extraPorts	Extra ports to expose in the service (normally used with the sidecar value)	nil
service.nodePorts.http	Kubernetes http node port	""

Discourse parameters

Parameter	Description	Default
discourse.host	Discourse host to create application URLs (include the port if =/= 80)	""
discourse.siteName	Discourse site name	My Site!
discourse.username	Admin user of the application	user
discourse.password	Application password (min length of 10 chars)	random 10 character long alphanumeric string
discourse.email	Admin user email of the application	user@example.com
discourse.command	Custom command to override image cmd	nil (evaluated as a template)
discourse.args	Custom args for the custom commad	nil (evaluated as a template)
discourse.containerSecurityContext	Container security context specification	{}
discourse.resources	Discourse container's resource requests and limits	{}
discourse.livenessProbe.enabled	Enable/disable livenessProbe	true
discourse.livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated	500
discourse.livenessProbe.periodSeconds	How often to perform the probe	10
discourse.livenessProbe.timeoutSeconds	When the probe times out	5
discourse.livenessProbe.failureThreshold	Minimum consecutive failures for the probe	6
discourse.livenessProbe.successThreshold	Minimum consecutive successes for the probe	1
discourse.readinessProbe.enabled	Enable/disable readinessProbe	true
discourse.readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated	30
discourse.readinessProbe.periodSeconds	How often to perform the probe	10
discourse.readinessProbe.timeoutSeconds	When the probe times out	5
discourse.readinessProbe.failureThreshold	Minimum consecutive failures for the probe	6
discourse.readinessProbe.successThreshold	Minimum consecutive successes for the probe	1
discourse.customLivenessProbe	Custom liveness probe to execute (when the main one is disabled)	{} (evaluated as a template)
discourse.customReadinessProbe	Custom readiness probe to execute (when the main one is disabled)	{} (evaluated as a template)
discourse.extraEnvVars	An array to add extra env vars	[] (evaluated as a template)
discourse.extraEnvVarsCM	Array to add extra configmaps	[]
discourse.extraEnvVarsSecret	Array to add extra environment from a Secret	nil
discourse.extraVolumeMounts	Additional volume mounts (used along with extraVolumes)	[] (evaluated as a template)
discourse.skipInstall	Do not run the Discourse installation wizard	false

Sidekiq parameters

Parameter	Description	Default
sidekiq.containerSecurityContext	Container security context specification	{}
sidekiq.command	Custom command to override image cmd (evaluated as a template)	["/app-entrypoint.sh"]
sidekiq.args	Custom args for the custom commad (evaluated as a template)	["nami", "start", "--foreground", "discourse-sidekiq"
sidekiq.resources	Sidekiq container's resource requests and limits	{}
sidekiq.livenessProbe.enabled	Enable/disable livenessProbe	true
sidekiq.livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated	500
sidekiq.livenessProbe.periodSeconds	How often to perform the probe	10
sidekiq.livenessProbe.timeoutSeconds	When the probe times out	5
sidekiq.livenessProbe.failureThreshold	Minimum consecutive failures for the probe	6
sidekiq.livenessProbe.successThreshold	Minimum consecutive successes for the probe	1
sidekiq.readinessProbe.enabled	Enable/disable readinessProbe	true
sidekiq.readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated	30
sidekiq.readinessProbe.periodSeconds	How often to perform the probe	10
sidekiq.readinessProbe.timeoutSeconds	When the probe times out	5
sidekiq.readinessProbe.failureThreshold	Minimum consecutive failures for the probe	6
sidekiq.readinessProbe.successThreshold	Minimum consecutive successes for the probe	1
sidekiq.customLivenessProbe	Custom liveness probe to execute (when the main one is disabled)	{} (evaluated as a template)
sidekiq.customReadinessProbe	Custom readiness probe to execute (when the main one is disabled)	{} (evaluated as a template)
sidekiq.extraEnvVars	An array to add extra env vars	[] (evaluated as a template)
sidekiq.extraEnvVarsCM	Array to add extra configmaps	[]
sidekiq.extraEnvVarsSecret	Array to add extra environment from a Secret	nil
discourse.extraVolumeMounts	Additional volume mounts (used along with extraVolumes)	[] (evaluated as a template)

Ingress parameters

Parameter	Description	Default
ingress.enabled	Enable ingress controller resource	false
ingress.certManager	Add annotations for cert-manager	false
ingress.hostname	Default host for the ingress resource	discourse.local
ingress.tls	Create TLS Secret	false
ingress.annotations	Ingress annotations	{} (evaluated as a template)
ingress.extraHosts[0].name	Additional hostnames to be covered	nil
ingress.extraHosts[0].path	Additional hostnames to be covered	nil
ingress.extraTls[0].hosts[0]	TLS configuration for additional hostnames to be covered	nil
ingress.extraTls[0].secretName	TLS configuration for additional hostnames to be covered	nil
ingress.secrets[0].name	TLS Secret Name	nil
ingress.secrets[0].certificate	TLS Secret Certificate	nil
ingress.secrets[0].key	TLS Secret Key	nil

Database parameters

Parameter	Description	Default
postgresql.enabled	Deploy PostgreSQL container(s)	true
postgresql.postgresqlUsername	PostgreSQL user to create (used by Discourse)	bn_discourse
postgresql.postgresqlPassword	Password for the Dicourse user	random 10 character long alphanumeric string
postgresql.postgresqlPostgresPassword	Password for the admin user ("postgres")	bitnami
postgresql.postgresqlDatabase	Name of the database to create	bitnami_application
postgresql.persistence.enabled	Enable database persistence using PVC	true
externalDatabase.host	Host of the external database	""
externalDatabase.port	Database port number	5432
externalDatabase.user	Existing username in the external db	bn_discourse
externalDatabase.password	Password for the above username	""
externalDatabase.postgresqlPostgresPassword	Password for the root "postgres" user (used in the installation stage)	""
externalDatabase.database	Name of the existing database	bitnami_application

Redis parameters

Parameter	Description	Default
redis.enabled	Deploy Redis container(s)	true
redis.usePassword	Use password authentication	false
redis.password	Password for Redis authentication	nil
redis.cluster.enabled	Whether to use cluster replication	false
redis.master.persistence.enabled	Enable database persistence using PVC	true
externalRedis.host	Host of the external database	""
externalRedis.port	Database port number	6379
externalRedis.password	Password for the above username	nil

The above parameters map to the env variables defined in bitnami/discourse. For more information please refer to the bitnami/discourse image documentation.

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

$ helm install my-release \
  --set discourse.username=admin,discourse.password=password,postgresql.postgresqlPassword=secretpassword \
    bitnami/discourse

The above command sets the Discourse administrator account username and password to admin and password respectively. Additionally, it sets the Postgresql bn_discourse user password to secretpassword.

Alternatively, a YAML file that specifies the values for the above parameters can be provided while installing the chart. For example,

$ helm install my-release -f values.yaml bitnami/discourse

Tip

: You can use the default values.yaml

Configuration and installation details

Rolling VS Immutable tags

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

Setting up replication

By default, this Chart only deploys a single pod running Discourse. Should you want to increase the number of replicas, you may follow these simple steps to ensure everything works smoothly:

Tip

: Running these steps ensures the PostgreSQL instance is correctly populated. If you already have an initialised DB, you may directly create a release with the desired number of replicas. Remind to set discourse.skipInstall to true!

1. Create a conventional release, that will be scaled later:

$ helm install my-release bitnami/discourse
...
export APP_PASSWORD=$(kubectl get secret --namespace default my-release-discourse -o jsonpath="{.data.discourse-password}" | base64 --decode)
export APP_DATABASE_PASSWORD=$(kubectl get secret --namespace default my-release-postgresql -o jsonpath="{.data.postgresql-password}" | base64 --decode)
...

2. Wait for the release to complete and Discourse to be running successfully.

$ kubectl get pods
NAME                               READY   STATUS    RESTARTS   AGE
my-release-discourse-744c48dd97-wx5h9   2/2     Running   0          5m11s
my-release-postgresql-0                 1/1     Running   0          5m10s
my-release-redis-master-0               1/1     Running   0          5m11s

3. Perform an upgrade specifying the number of replicas and the credentials used.

$ helm upgrade my-release --set replicaCount=2,discourse.password=$APP_PASSWORD,postgresql.postgresqlPassword=$APP_DATABASE_PASSWORD,discourse.skipInstall=true bitnami/discourse

Note that for this to work properly, you need to provide ReadWriteMany PVCs. If you don't have a provisioner for this type of storage, we recommend that you install the NFS provisioner chart (with the correct parameters, such as persistence.enabled=true and persistence.size=10Gi) and map it to a RWO volume.

Then you can deploy Discourse chart using the proper parameters:

persistence.storageClass=nfs
postgresql.persistence.storageClass=nfs

Production configuration

This chart includes a values-production.yaml file where you can find some parameters oriented to production configuration in comparison to the regular values.yaml. You can use this file instead of the default one.

• Enable client source IP preservation:

- service.externalTrafficPolicy: Cluster
+ service.externalTrafficPolicy: Local

• Make Redis use password for auth:

- redis.usePassword: false
+ redis.usePassword: true

• PVC Access Mode:

- persistence.accessMode: ReadWriteOnce
+ ## To use the portal and to ensure you can scale Discourse you need to provide a
+ ## ReadWriteMany PVC, if you dont have a provisioner for this type of storage
+ ## We recommend that you install the nfs provisioner and map it to a RWO volume
+ ## helm install nfs-server stable/nfs-server-provisioner --set persistence.enabled=true,persistence.size=10Gi
+ ##
+ persistence.accessMode: ReadWriteMany

Note that values-production.yaml specifies ReadWriteMany PVCs are specified. This is intended to ease the process of replication (see Setting up replication).

Sidecars

If you have a need for additional containers to run within the same pod as Discourse (e.g. metrics or logging exporter), you can do so via the sidecars config parameter. Simply define your container according to the Kubernetes container spec.

sidecars:
- name: your-image-name
  image: your-image
  imagePullPolicy: Always
  ports:
  - name: portname
   containerPort: 1234

If these sidecars export extra ports, you can add extra port definitions using the service.extraPorts value:

service:
...
  extraPorts:
  - name: extraPort
    port: 11311
    targetPort: 11311

Using an external database

Sometimes you may want to have Discourse connect to an external database rather than installing one inside your cluster, e.g. to use a managed database service, or use run a single database server for all your applications. To do this, the chart allows you to specify credentials for an external database under the externalDatabase parameter. You should also disable the PostgreSQL installation with the postgresql.enabled option. For example with the following parameters:

postgresql.enabled=false
externalDatabase.host=myexternalhost
externalDatabase.user=myuser
externalDatabase.password=mypassword
externalDatabase.postgresqlPostgresPassword=rootpassword
externalDatabase.database=mydatabase
externalDatabase.port=5432

Note also that if you disable PostgreSQL per above you MUST supply values for the externalDatabase connection.

In case the database already contains data from a previous Discourse installation, you need to set the discourse.skipInstall parameter to true. Otherwise, the container would execute the installation wizard and could modify the existing data in the database. This parameter force the container to not execute the Discourse installation wizard.

Similarly, you can specify an external Redis instance rather than installing one inside your cluster. First, you may disable the Redis installation with the redis.enabled option. As aforementioned, used the provided parameters to provide data about your instance:

redis.enabled=false
externalRedis.host=myexternalhost
externalRedis.password=mypassword
externalRedis.port=5432

Ingress

This chart provides support for ingress resources. If you have an ingress controller installed on your cluster, such as nginx-ingress or traefik you can utilize the ingress controller to serve your Discourse application.

To enable ingress integration, please set ingress.enabled to true

Hosts

Most likely you will only want to have one hostname that maps to this Discourse installation. If that's your case, the property ingress.hostname will set it. However, it is possible to have more than one host. To facilitate this, the ingress.extraHosts object can be specified as an array.

For each host indicated at ingress.extraHosts, please indicate a name, path, and any annotations that you may want the ingress controller to know about.

The actual TLS secret do not have to be generated by this chart. However, please note that if TLS is enabled, the ingress record will not work until this secret exists.

For annotations, please see this document. Not all annotations are supported by all ingress controllers, but this document does a good job of indicating which annotation is supported by many popular ingress controllers.

TLS Secrets

This chart will facilitate the creation of TLS secrets for use with the ingress controller, however, this is not required. There are three common use cases:

• Helm generates/manages certificate secrets
• User generates/manages certificates separately
• An additional tool (like kube-lego) manages the secrets for the application

In the first two cases, one will need a certificate and a key. We would expect them to look like this:

• certificate files should look like (and there can be more than one certificate if there is a certificate chain)

-----BEGIN CERTIFICATE-----
MIID6TCCAtGgAwIBAgIJAIaCwivkeB5EMA0GCSqGSIb3DQEBCwUAMFYxCzAJBgNV
...
jScrvkiBO65F46KioCL9h5tDvomdU1aqpI/CBzhvZn1c0ZTf87tGQR8NK7v7
-----END CERTIFICATE-----

• keys should look like:

-----BEGIN RSA PRIVATE KEY-----
MIIEogIBAAKCAQEAvLYcyu8f3skuRyUgeeNpeDvYBCDcgq+LsWap6zbX5f8oLqp4
...
wrj2wDbCDCFmfqnSJ+dKI3vFLlEz44sAV8jX/kd4Y6ZTQhlLbYc=
-----END RSA PRIVATE KEY-----

If you are going to use Helm to manage the certificates, please copy these values into the certificate and key values for a given ingress.secrets entry.

If you are going to manage TLS secrets outside of Helm, please know that you can create a TLS secret (named discourse.local-tls for example).

Please see this example for more information.

Persistence

The Bitnami Discourse image stores the Discourse data and configurations at the /bitnami path of the container.

Persistent Volume Claims are used to keep the data across deployments. This is known to work in GCE, AWS, and minikube. See the Parameters section to configure the PVC or to disable persistence.

Image

The image parameter allows specifying which image will be pulled for the chart.

Private registry

If you configure the image value to one in a private registry, you will need to specify an image pull secret.

1. Manually create image pull secret(s) in the namespace. See this YAML example reference. Consult your image registry's documentation about getting the appropriate secret.
2. Note that the imagePullSecrets configuration value cannot currently be passed to helm using the --set parameter, so you must supply these using a values.yaml file, such as:

imagePullSecrets:
  - name: SECRET_NAME

3. Install the chart