ClickHouse

Run ClickHouse column-oriented database on kubernetes

TL;DR;

Introduction

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

Quick start with minikube

# start minikube and install tiller
minikube start
helm init
kubectl patch deployment tiller-deploy -p '{"spec": {"template": {"spec": {"automountServiceAccountToken": true}}}}'

# install chart
helm upgrade --install clickhouse .

Seed the database manually

Terminal #1:

kubectl port-forward clickhouse-0 9000:9000

Terminal #2:

QUERY=$(cat conf/initdb.sql)
docker run -ti --network=host \
    --rm yandex/clickhouse-client \
    --host=docker.for.mac.localhost \
    --multiquery \
    --query="${QUERY}"

Installing the Chart

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

git clone https://github.com/tekn0ir/clickhouse_chart.git
cd clickhouse_chart
helm install --name my-release .

Uninstalling the Chart

To uninstall/delete the my-release deployment:

helm delete my-release

Configuration

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

Parameter	Description	Default
replicas	Number of nodes	1
image	clickhouse image repository	yandex/clickhouse-server
imageTag	clickhouse image tag	latest
imagePullPolicy	Image pull policy	Always
imagePullSecret	Image pull secrets	nil
persistence.enabled	Use a PVC to persist data	false
persistence.existingClaim	Provide an existing PersistentVolumeClaim	nil
persistence.storageClass	Storage class of backing PVC	default
persistence.accessMode	Use volume as ReadOnly or ReadWrite	ReadWriteOnce
persistence.annotations	Persistent Volume annotations	{}
persistence.size	Size of data volume	10Gi
resources.limits.cpu	CPU resource limit	1
resources.limits.memory	Memory resource limit	1Gi
resources.requests.cpu	CPU resource request	1
resources.requests.memory	Memory resource request	1Gi
service.externalIPs	External IPs to listen on	[]
service.port	TCP port	8123
service.type	k8s service type exposing ports, e.g. NodePort	ClusterIP
service.nodePort	NodePort value if service.type is NodePort	nil
service.annotations	Service annotations	{}
service.labels	Service labels	{}
ingress.enabled	Enables Ingress	false
ingress.annotations	Ingress annotations	{}
ingress.labels	Ingress labels	{}
ingress.hosts	Ingress accepted hostnames	[]
ingress.tls	Ingress TLS configuration	[]
nodeSelector	Node labels for pod assignment	{}
tolerations	Toleration labels for pod assignment	{}
podAnnotations	Annotations for the clickhouse pod	{}
annotations	Annotations for the clickhouse statefulset	{}
initdb_args	Arguments for the clickhouse-clinet init query	['--user=default', '--database=default', '--multiquery']
initdb_sql	Path to bootstrap sql query file	conf/initdb.sql
config_xml	Path to server config	conf/config.xml
users_xml	Path to users config	conf/users.xml

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

helm install --name my-release --set persistence.enabled=true .

Configuration files

Make a copy of values.yaml and conf dir:

cp values.yaml myconfig.yaml
cp -rf conf myconfig

Edit myconfig.yaml and point out files in myconfig dir:

initdb_sql: myconfig/initdb.sql
config_xml: myconfig/config.xml
users_xml: myconfig/users.xml

To use the edited myconfig.yaml:

helm install --name my-release -f myconfig.yaml .

Edit myconfig/config.xml and myconfig/users.xml according to server settings docs

User passwords can be generated:

echo -n "password" | sha256sum | tr -d '-' | tr -d ' '
# result: 5e884898da28047151d0e56f8dc6292773603d0d6aabbdd62a11ef721d1542d8

Bootstrapping database

Edit myconfig/initdb.sql boostrap script, to create tables and views you need according to query docs.