Creating Databases with KubeBlocks

Overview

KubeBlocks is an open-source Kubernetes operator and toolset designed to simplify the complexity of running and managing data infrastructure, such as databases, message queues, and streaming systems, on Kubernetes. It provides a declarative approach to deploying and managing stateful applications, allowing you to manage them as easily as stateless ones.

This guide will walk you through the process of creating a database cluster using KubeBlocks.

Why KubeBlocks?

Simplified Management: Automates the database lifecycle, including deployment, upgrades, scaling, and monitoring.

Production-Ready: Supports high availability, backup and restore, and robust monitoring.

Versatile: Supports a wide range of databases, including MySQL, PostgreSQL, MongoDB, Redis, and more.

Installing KubeBlocks

You can install KubeBlocks using Helm. For more installation options, refer to the KubeBlocks Installation Guide.

This guide will use Helm for the installation.

Step 1: Deploy Snapshot Controller

KubeBlocks requires the Snapshot Controller to manage volume snapshots. First, check if it is already installed in your cluster.

kubectl get crd volumesnapshotclasses.snapshot.storage.k8s.io
kubectl get crd volumesnapshots.snapshot.storage.k8s.io
kubectl get crd volumesnapshotcontents.snapshot.storage.k8s.io

If it is not installed, you can deploy it using the following commands:

```bash
helm repo add piraeus-charts https://piraeus.io/helm-charts/
helm repo update
# Update the namespace to an appropriate value for your environment (e.g. kb-system)
helm install snapshot-controller piraeus-charts/snapshot-controller -n kb-system --create-namespace

Then, verify the installation:

```bash
kubectl get pods -n kb-system | grep snapshot-controller

The Snapshot Controller should be in the `Running` state.

### Step 2: Get the Latest KubeBlocks Version

Get the latest stable version tag (e.g. v1.0.1):

```bash
curl -s "https://api.github.com/repos/apecloud/kubeblocks/releases?per_page=100&page=1" | jq -r '.[] | select(.prerelease == false) | .tag_name' | sort -V -r | head -n 1

# Example output:
# v1.0.1

### Step 3: Create KubeBlocks CRDs

Create the Custom Resource Definitions (CRDs) required by KubeBlocks.

```bash
# Replace <VERSION> with the version you selected
kubectl create -f https://github.com/apecloud/kubeblocks/releases/download/<VERSION>/kubeblocks_crds.yaml

# Example: If the version is v1.0.1
kubectl create -f https://github.com/apecloud/kubeblocks/releases/download/v1.0.1/kubeblocks_crds.yaml

### Step 4: Install KubeBlocks with Helm

1. **Add the KubeBlocks Helm repository:**

    ```bash
    helm repo add kubeblocks https://apecloud.github.io/helm-charts
    helm repo update

Install KubeBlocks: This command installs the KubeBlocks chart into the kb-system namespace.

helm install kubeblocks kubeblocks/kubeblocks --namespace kb-system --create-namespace

Creating a Database

Once KubeBlocks is installed, you can create a database cluster using kubectl.

Currently supported databases include:

Example: Creating a Demo MySQL Cluster

Create a file named my-mysql-cluster.yaml:

apiVersion: apps.kubeblocks.io/v1
kind: Cluster
metadata:
  name: mycluster
  namespace: demo
spec:
  # Deletes all resources when the cluster is deleted
  terminationPolicy: Delete
  componentSpecs:
    - name: mysql
      # Defines the MySQL component and version
      componentDef: "mysql-8.0" 
      serviceVersion: 8.0.35
      disableExporter: false
      # Number of replicas for high availability
      replicas: 2
      # Resource allocation for each replica
      resources:
        limits:
          cpu: '0.5'
          memory: 0.5Gi
        requests:
          cpu: '0.5'
          memory: 0.5Gi
      # Defines the persistent storage for data
      volumeClaimTemplates:
        - name: data
          spec:
            storageClassName: ""
            accessModes:
              - ReadWriteOnce
            resources:
              requests:
                storage: 20Gi

Apply the manifest to create the cluster:

kubectl apply -f my-mysql-cluster.yaml

More Information

For more detailed information, advanced configurations, and troubleshooting with KubeBlocks, please refer to the official KubeBlocks documentation.