charts/bitnami/ghost

Ghost

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

TL;DR

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/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 3.1.0
• 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/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.

Global parameters

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
image.registry	Ghost image registry	docker.io
image.repository	Ghost Image name	bitnami/ghost
image.tag	Ghost Image tag	{TAG_NAME}
image.pullPolicy	Ghost image pull policy	IfNotPresent
image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
image.debug	Specify if debug logs should be enabled	false
nameOverride	String to partially override common.names.fullname template	nil
fullnameOverride	String to fully override common.names.fullname template	nil
commonLabels	Labels to add to all deployed objects	nil
commonAnnotations	Annotations to add to all deployed objects	[]
extraDeploy	Array of extra objects to deploy with the release (evaluated as a template).	nil

Ghost parameters

Parameter	Description	Default
affinity	Map of node/pod affinities	{}
allowEmptyPassword	Allow DB blank passwords	true
args	Override default container args (useful when using custom images)	nil
command	Override default container command (useful when using custom images)	nil
hostAliases	Add deployment host aliases	[]
containerPorts.http	Sets http port inside Ghost container	8080
containerPorts.https	Sets https port inside Ghost container	8443
livenessProbe.enabled	Would you like a livenessProbe to be enabled	true
livenessProbe.initialDelaySeconds	Delay before liveness probe is initiated	120
livenessProbe.periodSeconds	How often to perform the probe	3
livenessProbe.timeoutSeconds	When the probe times out	5
livenessProbe.failureThreshold	Minimum consecutive failures to be considered failed	6
livenessProbe.successThreshold	Minimum consecutive successes to be considered successful	1
readinessProbe.enabled	Would you like a readinessProbe to be enabled	true
readinessProbe.initialDelaySeconds	Delay before readiness probe is initiated	30
readinessProbe.periodSeconds	How often to perform the probe	3
readinessProbe.timeoutSeconds	When the probe times out	5
readinessProbe.failureThreshold	Minimum consecutive failures to be considered failed	6
readinessProbe.successThreshold	Minimum consecutive successes to be considered successful	1
podSecurityContext.enabled	Enable security context	true
podSecurityContext.fsGroup	Group ID for the container	1001
podSecurityContext.runAsUser	User ID for the container	1001
containerSecurityContext.enabled	Enable Ghost containers' Security Context	true
containerSecurityContext.runAsUser	Ghost containers' Security Context	1001
containerSecurityContext.runAsNonRoot	Ghost containers' Security Context Non Root	true
customLivenessProbe	Override default liveness probe	nil
customReadinessProbe	Override default readiness probe	nil
existingSecret	Name of a secret with the application password	nil
extraEnvVarsConfigMap	ConfigMap containing extra env vars	nil
extraEnvVarsSecret	Secret containing extra env vars (in case of sensitive data)	nil
extraEnvVars	Extra environment variables	nil
extraVolumeMounts	Array of extra volume mounts to be added to the container (evaluated as template). Normally used with extraVolumes.	nil
extraVolumes	Array of extra volumes to be added to the deployment (evaluated as template). Requires setting extraVolumeMounts	nil
initContainers	Add additional init containers to the pod (evaluated as a template)	nil
lifecycleHooks	LifecycleHook to set additional configuration at startup Evaluated as a template	``
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
nodeAffinityPreset.type	Node affinity preset type. Ignored if affinity is set. Allowed values: soft or hard	""
nodeAffinityPreset.key	Node label key to match Ignored if affinity is set.	""
nodeAffinityPreset.values	Node label values to match. Ignored if affinity is set.	[]
nodeSelector	Node labels for pod assignment	{} (The value is evaluated as a template)
persistence.accessMode	PVC Access Mode for Ghost volume	ReadWriteOnce
persistence.enabled	Enable persistence using PVC	true
persistence.existingClaim	An Existing PVC name	nil
persistence.path	Host mount path for Ghost volume	nil (will not mount to a host path)
persistence.size	PVC Storage Request for Ghost volume	8Gi
persistence.storageClass	PVC Storage Class for Ghost volume	nil (uses alpha storage class annotation)
podAnnotations	Pod annotations	{}
podAffinityPreset	Pod affinity preset. Ignored if affinity is set. Allowed values: soft or hard	""
podAntiAffinityPreset	Pod anti-affinity preset. Ignored if affinity is set. Allowed values: soft or hard	soft
podLabels	Add additional labels to the pod (evaluated as a template)	nil
podSecurityContext.enabled	Enable Ghost pods' Security Context	true
podSecurityContext.fsGroup	Ghost pods' group ID	1001
priorityClassName	Define the priority class name to use for the ghost pods here.	""
replicaCount	Number of Ghost Pods to run	1
resources	CPU/Memory resource requests/limits	Memory: 512Mi, CPU: 300m
sidecars	Attach additional containers to the pod (evaluated as a template)	nil
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
tolerations	Tolerations for pod assignment	[] (The value is evaluated as a template)
updateStrategy	Deployment update strategy	RollingUpdate

Traffic Exposure Parameters

Parameter	Description	Default
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.loadBalancerSourceRanges	define loadBalancerSourceRanges if the service type is LoadBalancer	[]
service.annotations	Service annotations. Evaluated as a template	{}
service.extraPorts	Service extra ports, normally used with the sidecar value. Evaluated as a template	[]
ingress.enabled	Enable ingress controller resource	false
ingress.certManager	Add annotations for cert-manager	false
ingress.hostname	Default host for the ingress resource	ghost.local
ingress.path	Default path for the ingress resource	/
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.extraPaths	Additional arbitrary path/backend objects	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
mariadb.enabled	Whether to use the MariaDB chart	true
mariadb.architecture	MariaDB architecture (standalone or replication)	standalone
mariadb.auth.rootPassword	Password for the MariaDB root user	random 10 character alphanumeric string
mariadb.auth.database	Database name to create	bitnami_ghost
mariadb.auth.username	Database user to create	bn_ghost
mariadb.auth.password	Password for the database	random 10 character long alphanumeric string
mariadb.primary.persistence.enabled	Enable database persistence using PVC	true
mariadb.primary.persistence.existingClaim	Name of an existing PersistentVolumeClaim for MariaDB primary replicas	nil
mariadb.primary.persistence.accessMode	Database Persistent Volume Access Modes	[ReadWriteOnce]
mariadb.primary.persistence.size	Database Persistent Volume Size	8Gi
mariadb.primary.persistence.storageClass	MariaDB primary persistent volume storage Class	nil (uses alpha storage class annotation)
mariadb.primary.persistence.hostPath	Host mount path for MariaDB volume	nil (will not mount to a host path)
externalDatabase.user	Existing username in the external db	bn_ghost
externalDatabase.password	Password for the above username	nil
externalDatabase.existingSecret	Name of an existing secret resource containing the DB password in a 'mariadb-password' key	nil
externalDatabase.database	Name of the existing database	bitnami_ghost
externalDatabase.host	Host of the existing database	nil
externalDatabase.port	Port of the existing database	3306

Volume Permissions parameters

Parameter	Description	Default
volumePermissions.image.registry	Init container volume-permissions image registry	docker.io
volumePermissions.image.repository	Init container volume-permissions image name	bitnami/bitnami-shell
volumePermissions.image.tag	Init container volume-permissions image tag	"10"
volumePermissions.image.pullSecrets	Specify docker-registry secret names as an array	[] (does not add image pull secrets to deployed pods)
volumePermissions.image.pullPolicy	Init container volume-permissions image pull policy	Always
volumePermissions.resources	Init container resource requests/limit	nil

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 my-release \
  --set ghostUsername=admin,ghostPassword=password,mariadb.auth.rootPassword=secretpassword \
    bitnami/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.

NOTE: Once this chart is deployed, it is not possible to change the application's access credentials, such as usernames or passwords, using Helm. To change these application credentials after deployment, delete any persistent volumes (PVs) used by the chart and re-deploy it, or use the application's built-in administrative tools if available.

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/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

Setting Pod's affinity

This chart allows you to set your custom affinity using the affinity parameter. Find more information about Pod's affinity in the kubernetes documentation.

As an alternative, you can use of the preset configurations for pod affinity, pod anti-affinity, and node affinity available at the bitnami/common chart. To do so, set the podAffinityPreset, podAntiAffinityPreset, or nodeAffinityPreset parameters.

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.

Troubleshooting

Find more information about how to deal with common errors related to Bitnami’s Helm charts in this troubleshooting guide.

Upgrading

To 12.0.0

This version standardizes the way of defining Ingress rules. When configuring a single hostname for the Ingress rule, set the ingress.hostname value. When defining more than one, set the ingress.extraHosts array. Apart from this case, no issues are expected to appear when upgrading.

To 11.0.0

In this major there were two main changes introduced:

1. Adaptation to Helm v2 EOL
2. Updated MariaDB dependency version

Please read the update notes carefully.

1. Adaptation to Helm v2 EOL

On November 13, 2020, Helm v2 support was formally finished, this major version is the result of the required changes applied to the Helm Chart to be able to incorporate the different features added in Helm v3 and to be consistent with the Helm project itself regarding the Helm v2 EOL.

What changes were introduced in this major version?

• Previous versions of this Helm Chart use apiVersion: v1 (installable by both Helm 2 and 3), this Helm Chart was updated to apiVersion: v2 (installable by Helm 3 only). Here you can find more information about the apiVersion field.
• Move dependency information from the requirements.yaml to the Chart.yaml
• After running helm dependency update, a Chart.lock file is generated containing the same structure used in the previous requirements.lock
• The different fields present in the Chart.yaml file has been ordered alphabetically in a homogeneous way for all the Bitnami Helm Charts

Considerations when upgrading to this version

• If you want to upgrade to this version from a previous one installed with Helm v3, you shouldn't face any issues
• If you want to upgrade to this version using Helm v2, this scenario is not supported as this version doesn't support Helm v2 anymore
• If you installed the previous version with Helm v2 and wants to upgrade to this version with Helm v3, please refer to the official Helm documentation about migrating from Helm v2 to v3

Useful links

• https://docs.bitnami.com/tutorials/resolve-helm2-helm3-post-migration-issues/
• https://helm.sh/docs/topics/v2_v3_migration/
• https://helm.sh/blog/migrate-from-helm-v2-to-helm-v3/

2. Updated MariaDB dependency version

In this major the MariaDB dependency version was also bumped to a new major version that introduces several incompatilibites. Therefore, backwards compatibility is not guaranteed unless an external database is used. Check MariaDB Upgrading Notes for more information.

To upgrade to 11.0.0, it should be done reusing the PVCs used to hold both the MariaDB and Ghost data on your previous release. To do so, follow the instructions below (the following example assumes that the release name is ghost):

NOTE: Please, create a backup of your database before running any of those actions. The steps below would be only valid if your application (e.g. any plugins or custom code) is compatible with MariaDB 10.5.x

Obtain the credentials and the name of the PVC used to hold the MariaDB data on your current release:

$ export GHOST_HOST=$(kubectl get svc --namespace default ghost --template "{{ range (index .status.loadBalancer.ingress 0) }}{{ . }}{{ end }}")
$ export GHOST_PASSWORD=$(kubectl get secret --namespace default ghost -o jsonpath="{.data.ghost-password}" | base64 --decode)
$ export MARIADB_ROOT_PASSWORD=$(kubectl get secret --namespace default ghost-mariadb -o jsonpath="{.data.mariadb-root-password}" | base64 --decode)
$ export MARIADB_PASSWORD=$(kubectl get secret --namespace default ghost-mariadb -o jsonpath="{.data.mariadb-password}" | base64 --decode)
$ export MARIADB_PVC=$(kubectl get pvc -l app=mariadb,component=master,release=ghost -o jsonpath="{.items[0].metadata.name}")

Delete the Ghost deployment and delete the MariaDB statefulset. Notice the option --cascade=false in the latter.

$ kubectl delete deployments.apps ghost

$ kubectl delete statefulsets.apps ghost-mariadb --cascade=false

Upgrade you release to 11.0.0 reusing the existing PVC, and enabling back MariaDB:

$ helm upgrade ghost bitnami/ghost --set mariadb.primary.persistence.existingClaim=$MARIADB_PVC --set mariadb.auth.rootPassword=$MARIADB_ROOT_PASSWORD --set mariadb.auth.password=$MARIADB_PASSWORD --set ghostPassword=$GHOST_PASSWORD --set ghostHost=$GHOST_HOST

You will need to kill the existing MariaDB pod now as the new statefulset is going to create a new one:

$ kubectl delete pod ghost-mariadb-0

You should see the lines below in MariaDB container logs:

$ kubectl logs $(kubectl get pods -l app.kubernetes.io/instance=ghost,app.kubernetes.io/name=mariadb,app.kubernetes.io/component=primary -o jsonpath="{.items[0].metadata.name}")
...
mariadb 12:13:24.98 INFO  ==> Using persisted data
mariadb 12:13:25.01 INFO  ==> Running mysql_upgrade
...

To 10.0.0

This version introduces bitnami/common, a library chart as a dependency. More documentation about this new utility could be found here. Please, make sure that you have updated the chart dependencies before executing any upgrade.

Also, allowEmptyPassword has changed its value type from string to boolean, if you were using it please make sure that you are passing the proper value.

# before
--set allowEmptyPassword="no"
# after
--set allowEmptyPassword=false

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