Ghost

Ghost is one of the most versatile open source content management systems on the market.

TL;DR;

$ helm install stable/ghost

Introduction

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

It also packages the Bitnami MariaDB chart which is required for bootstrapping a MariaDB deployment for the database requirements of the Ghost application.

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters. This chart has been tested to work with NGINX Ingress, cert-manager, fluentd and Prometheus on top of the BKPR.

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 --name my-release stable/ghost

The command deploys Ghost 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 Ghost 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
image.registry	Ghost image registry	docker.io
image.repository	Ghost Image name	bitnami/ghost
image.tag	Ghost Image tag	{TAG_NAME}
image.pullPolicy	Image pull policy	IfNotPresent
image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
nameOverride	String to partially override ghost.fullname template with a string (will prepend the release name)	nil
fullnameOverride	String to fully override ghost.fullname template with a string	nil
volumePermissions.image.registry	Init container volume-permissions image registry	docker.io
volumePermissions.image.repository	Init container volume-permissions image name	bitnami/minideb
volumePermissions.image.tag	Init container volume-permissions image tag	stretch
volumePermissions.image.pullPolicy	Init container volume-permissions image pull policy	Always
ghostHost	Ghost host to create application URLs	nil
ghostPort	Ghost port to use in application URLs (defaults to service.port if nil)	nil
ghostProtocol	Protocol (http or https) to use in the application URLs	http
ghostPath	Ghost path to create application URLs	nil
ghostUsername	User of the application	user@example.com
ghostPassword	Application password	Randomly generated
ghostEmail	Admin email	user@example.com
ghostBlogTitle	Ghost Blog name	User's Blog
smtpHost	SMTP host	nil
smtpPort	SMTP port	nil
smtpUser	SMTP user	nil
smtpPassword	SMTP password	nil
smtpFromAddress	SMTP from address	nil
smtpService	SMTP service	nil
allowEmptyPassword	Allow DB blank passwords	yes
securityContext.enabled	Enable security context	true
securityContext.fsGroup	Group ID for the container	1001
securityContext.runAsUser	User ID for the container	1001
service.type	Kubernetes Service type	LoadBalancer
service.port	Service HTTP port	80
service.nodePorts.http	Kubernetes http node port	""
service.externalTrafficPolicy	Enable client source IP preservation	Cluster
service.loadBalancerIP	LoadBalancerIP for the Ghost service	``
service.annotations	Service annotations	``
ingress.enabled	Enable ingress controller resource	false
ingress.annotations	Ingress annotations	[]
ingress.certManager	Add annotations for cert-manager	false
ingress.hosts[0].name	Hostname to your Ghost installation	ghost.local
ingress.hosts[0].path	Path within the url structure	/
ingress.hosts[0].tls	Utilize TLS backend in ingress	false
ingress.hosts[0].tlsHosts	Array of TLS hosts for ingress record (defaults to ingress.hosts[0].name if nil)	nil
ingress.hosts[0].tlsSecret	TLS Secret (certificates)	ghost.local-tls-secret
ingress.secrets[0].name	TLS Secret Name	nil
ingress.secrets[0].certificate	TLS Secret Certificate	nil
ingress.secrets[0].key	TLS Secret Key	nil
externalDatabase.host	Host of the external database	localhost
externalDatabase.port	Port of the external database	3306
externalDatabase.user	Existing username in the external db	bn_ghost
externalDatabase.password	Password for the above username	""
externalDatabase.database	Name of the existing database	bitnami_ghost
mariadb.enabled	Whether or not to install MariaDB (disable if using external)	true
mariadb.rootUser.password	MariaDB admin password	nil
mariadb.db.name	MariaDB Database name to create	bitnami_ghost
mariadb.db.user	MariaDB Database user to create	bn_ghost
mariadb.db.password	MariaDB Password for user	random 10 character long alphanumeric string
persistence.enabled	Enable persistence using PVC	true
persistence.storageClass	PVC Storage Class for Ghost volume	nil (uses alpha storage annotation)
persistence.accessMode	PVC Access Mode for Ghost volume	ReadWriteOnce
persistence.size	PVC Storage Request for Ghost volume	8Gi
persistence.path	Path to mount the volume at, to use other images	/bitnami
resources	CPU/Memory resource requests/limits	Memory: 512Mi, CPU: 300m
affinity	Map of node/pod affinities	{}

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

Note:

For the Ghost application function correctly, you should specify the ghostHost parameter to specify the FQDN (recommended) or the public IP address of the Ghost service.

Optionally, you can specify the ghostLoadBalancerIP parameter to assign a reserved IP address to the Ghost service of the chart. However please note that this feature is only available on a few cloud providers (f.e. GKE).

To reserve a public IP address on GKE:

$ gcloud compute addresses create ghost-public-ip

The reserved IP address can be assigned to the Ghost service by specifying it as the value of the ghostLoadBalancerIP parameter while installing the chart.

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

$ helm install --name my-release \
  --set ghostUsername=admin,ghostPassword=password,mariadb.mariadbRootPassword=secretpassword \
    stable/ghost

The above command sets the Ghost administrator account username and password to admin and password respectively. Additionally, it sets the MariaDB root 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 --name my-release -f values.yaml stable/ghost

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.

Using an existing database

Sometimes you may want to have Ghost 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 MariaDB installation with the mariadb.enabled option. For example using the following parameters:

mariadb.enabled=false
externalDatabase.host=myexternalhost
externalDatabase.user=myuser
externalDatabase.password=mypassword
externalDatabase.database=mydatabase

Persistence

The Bitnami Ghost image stores the Ghost data and configurations at the /bitnami/ghost and /bitnami/apache paths 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.

Upgrading

To 9.0.0

Helm performs a lookup for the object based on its group (apps), version (v1), and kind (Deployment). Also known as its GroupVersionKind, or GVK. Changing the GVK is considered a compatibility breaker from Kubernetes' point of view, so you cannot "upgrade" those objects to the new GVK in-place. Earlier versions of Helm 3 did not perform the lookup correctly which has since been fixed to match the spec.

In https://github.com/helm/charts/pulls/17297 the apiVersion of the deployment resources was updated to apps/v1 in tune with the api's deprecated, resulting in compatibility breakage.

This major version signifies this change.

To 5.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 5.0.0. The following example assumes that the release name is ghost:

$ kubectl patch deployment ghost-ghost --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'
$ kubectl delete statefulset ghost-mariadb --cascade=false