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bitnamicharts/clickhouse

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By VMware

Updated 8 days ago

Bitnami Helm chart for ClickHouse

Helm
Image
Data Science
Databases & Storage
Web Analytics
0

1M+

Bitnami package for ClickHouse

ClickHouse is an open-source column-oriented OLAP database management system. Use it to boost your database performance while providing linear scalability and hardware efficiency.

Overview of ClickHouse

Trademarks: This software listing is packaged by Bitnami. The respective trademarks mentioned in the offering are owned by the respective companies, and use of them does not imply any affiliation or endorsement.

TL;DR

helm install my-release oci://registry-1.docker.io/bitnamicharts/clickhouse

Looking to use ClickHouse in production? Try VMware Tanzu Application Catalog, the commercial edition of the Bitnami catalog.

Introduction

Bitnami charts for Helm are carefully engineered, actively maintained and are the quickest and easiest way to deploy containers on a Kubernetes cluster that are ready to handle production workloads.

This chart bootstraps a ClickHouse Deployment in a Kubernetes cluster using the Helm package manager.

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

Prerequisites

  • Kubernetes 1.23+
  • Helm 3.8.0+
  • PV provisioner support in the underlying infrastructure
  • ReadWriteMany volumes for deployment scaling

If you are using Kubernetes 1.18, the following code needs to be commented out. seccompProfile: type: "RuntimeDefault"

Installing the Chart

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

helm install my-release oci://REGISTRY_NAME/REPOSITORY_NAME/clickhouse

Note: You need to substitute the placeholders REGISTRY_NAME and REPOSITORY_NAME with a reference to your Helm chart registry and repository. For example, in the case of Bitnami, you need to use REGISTRY_NAME=registry-1.docker.io and REPOSITORY_NAME=bitnamicharts.

The command deploys ClickHouse 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

Configuration and installation details

Resource requests and limits

Bitnami charts allow setting resource requests and limits for all containers inside the chart deployment. These are inside the resources value (check parameter table). Setting requests is essential for production workloads and these should be adapted to your specific use case.

To make this process easier, the chart contains the resourcesPreset values, which automatically sets the resources section according to different presets. Check these presets in the bitnami/common chart. However, in production workloads using resourcesPreset is discouraged as it may not fully adapt to your specific needs. Find more information on container resource management in the official Kubernetes documentation.

Prometheus metrics

This chart can be integrated with Prometheus by setting metrics.enabled to true. This will expose Clickhouse native Prometheus endpoint in the service. It will have the necessary annotations to be automatically scraped by Prometheus.

Prometheus requirements

It is necessary to have a working installation of Prometheus or Prometheus Operator for the integration to work. Install the Bitnami Prometheus helm chart or the Bitnami Kube Prometheus helm chart to easily have a working Prometheus in your cluster.

Integration with Prometheus Operator

The chart can deploy ServiceMonitor objects for integration with Prometheus Operator installations. To do so, set the value metrics.serviceMonitor.enabled=true. Ensure that the Prometheus Operator CustomResourceDefinitions are installed in the cluster or it will fail with the following error:

no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"

Install the Bitnami Kube Prometheus helm chart for having the necessary CRDs and the Prometheus Operator.

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.

Update credentials

Bitnami charts configure credentials at first boot. Any further change in the secrets or credentials require manual intervention. Follow these instructions:

  • Update the user password following the upstream documentation
  • Update the password secret with the new values (replace the SECRET_NAME, and PASSWORD placeholders)
kubectl create secret generic SECRET_NAME --from-literal=admin-password=PASSWORD --dry-run -o yaml | kubectl apply -f -
ClickHouse keeper support

You can set keeper.enabled to use ClickHouse keeper. If keeper.enabled=true, Zookeeper settings will be ignore.

External Zookeeper support

You may want to have ClickHouse connect to an external zookeeper rather than installing one inside your cluster. Typical reasons for this are to use a managed database service, or to share a common database server for all your applications. To achieve this, the chart allows you to specify credentials for an external database with the externalZookeeper parameter. You should also disable the Zookeeper installation with the zookeeper.enabled option. Here is an example:

zookeper.enabled=false
externalZookeeper.host=myexternalhost
externalZookeeper.user=myuser
externalZookeeper.password=mypassword
externalZookeeper.database=mydatabase
externalZookeeper.port=3306
Ingress without TLS

For using ingress (example without TLS):

ingress:
  ## If true, ClickHouse server Ingress will be created
  ##
  enabled: true

  ## ClickHouse server Ingress annotations
  ##
  annotations: {}
  #   kubernetes.io/ingress.class: nginx
  #   kubernetes.io/tls-acme: 'true'

  ## ClickHouse server Ingress hostnames
  ## Must be provided if Ingress is enabled
  ##
  hosts:
    - clickhouse.domain.com
Ingress TLS

If your cluster allows automatic creation/retrieval of TLS certificates, please refer to the documentation for that mechanism.

To manually configure TLS, first create/retrieve a key & certificate pair for the address(es) you wish to protect. Then create a TLS secret (named clickhouse-server-tls in this example) in the namespace. Include the secret's name, along with the desired hostnames, in the Ingress TLS section of your custom values.yaml file:

ingress:
  ## If true, ClickHouse server Ingress will be created
  ##
  enabled: true

  ## ClickHouse server Ingress annotations
  ##
  annotations: {}
  #   kubernetes.io/ingress.class: nginx
  #   kubernetes.io/tls-acme: 'true'

  ## ClickHouse server Ingress hostnames
  ## Must be provided if Ingress is enabled
  ##
  hosts:
    - clickhouse.domain.com

  ## ClickHouse server Ingress TLS configuration
  ## Secrets must be manually created in the namespace
  ##
  tls:
    - secretName: clickhouse-server-tls
      hosts:
        - clickhouse.domain.com
Securing traffic using TLS

This chart facilitates the creation of TLS secrets for use with the Ingress controller (although this is not mandatory). There are several common use cases:

  • Generate certificate secrets based on chart parameters.
  • Enable externally generated certificates.
  • Manage application certificates via an external service (like cert-manager).
  • Create self-signed certificates within the chart (if supported).

In the first two cases, a certificate and a key are needed. Files are expected in .pem format.

Here is an example of a certificate file:

NOTE: There may be more than one certificate if there is a certificate chain.

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

Here is an example of a certificate key:

-----BEGIN RSA PRIVATE KEY-----
MIIEogIBAAKCAQEAvLYcyu8f3skuRyUgeeNpeDvYBCDcgq+LsWap6zbX5f8oLqp4
...
wrj2wDbCDCFmfqnSJ+dKI3vFLlEz44sAV8jX/kd4Y6ZTQhlLbYc=
-----END RSA PRIVATE KEY-----
  • If using Helm to manage the certificates based on the parameters, copy these values into the certificate and key values for a given *.ingress.secrets entry.
  • If managing TLS secrets separately, it is necessary to create a TLS secret with name INGRESS_HOSTNAME-tls (where INGRESS_HOSTNAME is a placeholder to be replaced with the hostname you set using the *.ingress.hostname parameter).
  • If your cluster has a cert-manager add-on to automate the management and issuance of TLS certificates, add to *.ingress.annotations the corresponding ones for cert-manager.
  • If using self-signed certificates created by Helm, set both *.ingress.tls and *.ingress.selfSigned to true.
Additional environment variables

In case you want to add extra environment variables (useful for advanced operations like custom init scripts), you can use the extraEnvVars property.

clickhouse:
  extraEnvVars:
    - name: LOG_LEVEL
      value: error

Alternatively, you can use a ConfigMap or a Secret with the environment variables. To do so, use the extraEnvVarsCM or the extraEnvVarsSecret values.

Sidecars

If additional containers are needed in the same pod as ClickHouse (such as additional metrics or logging exporters), they can be defined using the sidecars parameter.

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

If these sidecars export extra ports, extra port definitions can be added using the service.extraPorts parameter (where available), as shown in the example below:

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

NOTE: This Helm chart already includes sidecar containers for the Prometheus exporters (where applicable). These can be activated by adding the --enable-metrics=true parameter at deployment time. The sidecars parameter should therefore only be used for any extra sidecar containers.

If additional init containers are needed in the same pod, they can be defined using the initContainers parameter. Here is an example:

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

Learn more about sidecar containers and init containers.

Using custom scripts

For advanced operations, the Bitnami ClickHouse chart allows using custom init and start scripts that will be mounted in /docker-entrypoint.initdb.d and /docker-entrypoint.startdb.d . The init scripts will be run on the first boot whereas the start scripts will be run on every container start. For adding the scripts directly as values use the initdbScripts and startdbScripts values. For using Secrets use the initdbScriptsSecret and startdbScriptsSecret.

initdbScriptsSecret: init-scripts-secret
startdbScriptsSecret: start-scripts-secret
Pod affinity

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

As an alternative, use one 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.

Backup and restore

To back up and restore Helm chart deployments on Kubernetes, you need to back up the persistent volumes from the source deployment and attach them to a new deployment using Velero, a Kubernetes backup/restore tool. Find the instructions for using Velero in this guide.

Persistence

The Bitnami ClickHouse image stores the ClickHouse 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.

Parameters

Global parameters
NameDescriptionValue
global.imageRegistryGlobal Docker image registry""
global.imagePullSecretsGlobal Docker registry secret names as an array[]
global.defaultStorageClassGlobal default StorageClass for Persistent Volume(s)""
global.storageClassDEPRECATED: use global.defaultStorageClass instead""
global.security.allowInsecureImagesAllows skipping image verificationfalse
global.compatibility.openshift.adaptSecurityContextAdapt the securityContext sections of the deployment to make them compatible with Openshift restricted-v2 SCC: remove runAsUser, runAsGroup and fsGroup and let the platform use their allowed default IDs. Possible values: auto (apply if the detected running cluster is Openshift), force (perform the adaptation always), disabled (do not perform adaptation)auto
Common parameters
NameDescriptionValue
kubeVersionOverride Kubernetes version""
nameOverrideString to partially override common.names.name""
fullnameOverrideString to fully override common.names.fullname""
namespaceOverrideString to fully override common.names.namespace""
commonLabelsLabels to add to all deployed objects{}
commonAnnotationsAnnotations to add to all deployed objects{}
clusterDomainKubernetes cluster domain namecluster.local
extraDeployArray of extra objects to deploy with the release[]
diagnosticMode.enabledEnable diagnostic mode (all probes will be disabled and the command will be overridden)false
diagnosticMode.commandCommand to override all containers in the deployment["sleep"]
diagnosticMode.argsArgs to override all containers in the deployment["infinity"]
ClickHouse Parameters
NameDescriptionValue
image.registryClickHouse image registryREGISTRY_NAME
image.repositoryClickHouse image repositoryREPOSITORY_NAME/clickhouse
image.digestClickHouse image digest in the way sha256:aa.... Please note this parameter, if set, will override the tag""
image.pullPolicyClickHouse image pull policyIfNotPresent
image.pullSecretsClickHouse image pull secrets[]
image.debugEnable ClickHouse image debug modefalse
clusterNameClickHouse cluster namedefault
shardsNumber of ClickHouse shards to deploy2
replicaCountNumber of ClickHouse replicas per shard to deploy3
distributeReplicasByZoneSchedules replicas of the same shard to different availability zonesfalse
containerPorts.httpClickHouse HTTP container port8123
containerPorts.httpsClickHouse HTTPS container port8443
containerPorts.tcpClickHouse TCP container port9000
containerPorts.tcpSecureClickHouse TCP (secure) container port9440
containerPorts.keeperClickHouse keeper TCP container port2181
containerPorts.keeperSecureClickHouse keeper TCP (secure) container port3181
containerPorts.keeperInterClickHouse keeper interserver TCP container port9444
containerPorts.mysqlClickHouse MySQL

Note: the README for this chart is longer than the DockerHub length limit of 25000, so it has been trimmed. The full README can be found at https://github.com/bitnami/charts/blob/main/bitnami/clickhouse/README.md

Docker Pull Command

docker pull bitnamicharts/clickhouse
Bitnami