Set Up ScalarDB Cluster on Kubernetes by Using a Helm Chart
This document provides instructions on how to set up a ScalarDB Cluster by using a Helm Chart on a Kubernetes cluster, specifically designed for a test environment.
Prerequisites
- Kubernetes cluster (such as MiniKube or Kind)
- kubectl
- Helm
In addition, you need access to the ScalarDB Cluster Node docker image. This repository is available only to users with a commercial license and permission. To get a license and permission, please contact us.
What you will create
You will be deploying the following components on a Kubernetes cluster as depicted below:
+---------------------------------------------------------------------------------------------------------------------------------------+
| [Kubernetes Cluster] |
| |
| [Pod] [Pod] [Pod] |
| |
| +-------+ |
| +---> | Envoy | ---+ |
| | +-------+ | |
| | | |
| +---------+ | +-------+ | +--------------------+ |
| | Service | ---+---> | Envoy | ---+---------> | Service | ---+ |
| | (Envoy) | | +-------+ | | (ScalarDB Cluster) | | |
| +---------+ | | +--------------------+ | +-----------------------+ |
| | +-------+ | | +---> | ScalarDB Cluster Node | ---+ |
| +---> | Envoy | ---+ | | +-----------------------+ | |
| +-------+ | | | |
| | | +-----------------------+ | +------------+ |
| +---+---> | ScalarDB Cluster Node | ---+---> | PostgreSQL | |
| | | +-----------------------+ | +------------+ |
| | | | |
| | | +-----------------------+ | |
| | +---> | ScalarDB Cluster Node | ---+ |
| | +-----------------------+ |
| +----------------------------+ | |
| | Service | ---+ |
| | (ScalarDB Cluster GraphQL) | |
| +----------------------------+ |
| |
+---------------------------------------------------------------------------------------------------------------------------------------+
Step 1. Start a PostgreSQL container
ScalarDB Cluster must use some kind of database system as its backend database. The database that is used in this document is PostgreSQL.
You can deploy PostgreSQL on the Kubernetes cluster as follows:
-
Add the Bitnami helm repository:
helm repo add bitnami https://charts.bitnami.com/bitnami -
Deploy PostgreSQL:
helm install postgresql-scalardb-cluster bitnami/postgresql \
--set auth.postgresPassword=postgres \
--set primary.persistence.enabled=false -
Check if the PostgreSQL container is running:
kubectl get podCommand execution result:
NAME READY STATUS RESTARTS AGE
postgresql-scalardb-cluster-0 1/1 Running 0 17s
Step 2. Deploy ScalarDB Cluster on the Kubernetes cluster by using a Helm Chart
-
Add the Scalar helm repository:
helm repo add scalar-labs https://scalar-labs.github.io/helm-charts -
Create a secret resource to pull the ScalarDB Cluster container images from GitHub packages:
kubectl create secret docker-registry reg-docker-secrets \
--docker-server=ghcr.io \
--docker-username=<YOUR_GITHUB_USERNAME> \
--docker-password=<YOUR_PERSONAL_ACCESS_TOKEN> -
Create a custom values file for ScalarDB Cluster (
scalardb-cluster-custom-values.yaml):cat << 'EOF' > scalardb-cluster-custom-values.yaml
envoy:
enabled: true
service:
type: "LoadBalancer"
scalardbCluster:
scalardbClusterNodeProperties: |
# ScalarDB Cluster configurations
scalar.db.cluster.membership.type=KUBERNETES
scalar.db.cluster.membership.kubernetes.endpoint.namespace_name=${env:SCALAR_DB_CLUSTER_MEMBERSHIP_KUBERNETES_ENDPOINT_NAMESPACE_NAME}
scalar.db.cluster.membership.kubernetes.endpoint.name=${env:SCALAR_DB_CLUSTER_MEMBERSHIP_KUBERNETES_ENDPOINT_NAME}
# Storage configurations
scalar.db.storage=jdbc
scalar.db.contact_points=jdbc:postgresql://postgresql-scalardb-cluster.default.svc.cluster.local:5432/postgres
scalar.db.username=postgres
scalar.db.password=postgres
# For ScalarDB Cluster GraphQL tutorial.
scalar.db.graphql.enabled=true
scalar.db.graphql.namespaces=emoney
# For ScalarDB Cluster SQL tutorial.
scalar.db.sql.enabled=true
graphql:
enabled: true
service:
type: "LoadBalancer"
EOFFor the tutorials, the service type for ScalarDB Cluster GraphQL and Envoy is set to
LoadBalancer. -
Deploy ScalarDB Cluster:
helm install scalardb-cluster scalar-labs/scalardb-cluster -f ./scalardb-cluster-custom-values.yaml -
Check if the ScalarDB Cluster pods are deployed:
kubectl get podCommand execution result:
NAME READY STATUS RESTARTS AGE
postgresql-scalardb-cluster-0 1/1 Running 0 84s
scalardb-cluster-envoy-59899dc588-477tg 1/1 Running 0 35s
scalardb-cluster-envoy-59899dc588-dpvhx 1/1 Running 0 35s
scalardb-cluster-envoy-59899dc588-lv9hx 1/1 Running 0 35s
scalardb-cluster-node-866c756c79-5v2tk 1/1 Running 0 35s
scalardb-cluster-node-866c756c79-9zhq5 1/1 Running 0 35s
scalardb-cluster-node-866c756c79-t6v86 1/1 Running 0 35sIf the ScalarDB Cluster Node Pods and the Envoy Pods are deployed properly, the
STATUSfor each pod will beRunning. -
Check if the service resources of the ScalarDB Cluster are deployed:
kubectl get svcCommand execution result:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 260d
postgresql-scalardb-cluster ClusterIP 10.110.97.40 <none> 5432/TCP 86s
postgresql-scalardb-cluster-hl ClusterIP None <none> 5432/TCP 86s
scalardb-cluster-envoy LoadBalancer 10.105.121.51 localhost 60053:30641/TCP 49s
scalardb-cluster-envoy-metrics ClusterIP 10.111.131.189 <none> 9001/TCP 49s
scalardb-cluster-graphql LoadBalancer 10.105.74.214 localhost 8080:30514/TCP 49s
scalardb-cluster-headless ClusterIP None <none> 60053/TCP 49s
scalardb-cluster-metrics ClusterIP 10.110.132.22 <none> 9080/TCP 49sIf the service resources of ScalarDB Cluster and Envoy are deployed properly, the private IP addresses in the
CLUSTER-IPcolumn will be displayed. (Note:scalardb-cluster-headlesshas noCLUSTER-IPaddress.) You can also seeEXTERNAL-IPaddresses assigned to the service resource of ScalarDB Cluster GraphQL (scalardb-cluster-graphql) and the service resource of Envoy (scalardb-cluster-envoy) asTYPEis set toLoadBalancer.In addition, the access method to the
LoadBalancerservice from your environment depends on each Kubernetes distribution. For example:- If you use Minikube, you can use the
minikube tunnelcommand. - If you use Kind, you can use MetalLB.
For details on how to access the
LoadBalancerservice, see the official documents of the Kubernetes distribution that you use. - If you use Minikube, you can use the
Delete all resources
You can delete all resources created in this document by running the following command:
helm uninstall scalardb-cluster postgresql-scalardb-cluster
Next steps
To get familiar with other use cases for ScalarDB Cluster, try the following tutorials: