MariaDB Operator for Kubernetes

This is a MariaDB Operator, which makes management of MariaDB instances (or clusters) running inside Kubernetes clusters easy. It was built with the Operator SDK using Ansible.

Usage

This Kubernetes Operator is meant to be deployed in your Kubernetes cluster(s) and can manage one or more MariaDB database instances or clusters in any namespace.

First you need to deploy MariaDB Operator into your cluster:

kubectl apply -f https://raw.githubusercontent.com/geerlingguy/mariadb-operator/master/deploy/mariadb-operator.yaml

Then you can create instances of MariaDB in any namespace, for example:

1. Create a file named my-database.yml with the following contents:

   ---
   apiVersion: mariadb.mariadb.com/v1alpha1
   kind: MariaDB
   metadata:
     name: example-mariadb
     namespace: example-mariadb
   spec:
     masters: 1
     replicas: 0
     mariadb_password: CHANGEME
     mariadb_image: mariadb:10.4
     mariadb_pvc_storage_request: 1Gi
   

2. Use kubectl to create the MariaDB instance in your cluster:

   kubectl apply -f my-database.yml
   

You can also deploy MariaDB instances into other namespaces by changing metadata.namespace, or deploy multiple MariaDB instances into the same namespace by changing metadata.name.

Connecting to the running database

Once the database instance has been deployed and initialized (this can take up to a few minutes), you can connect to it using the MySQL CLI from within the same namespace as your database instance, for example:

kubectl -n example-mariadb run -it --rm mysql-client --image=arey/mysql-client --restart=Never -- -h example-mariadb-0.example-mariadb.example-mariadb.svc.cluster.local -u db_user -pCHANGEME -D db

Other applications can connect to the database instance from within the same namespace using the following connection parameters:

• Host: example-mariadb-0.example-mariadb.example-mariadb.svc.cluster.local
• Username: db_user
• Password: CHANGEME
• Database: db

Exposing an instance to the outside world

You can also expose a database instance to the outside world by adding a Service to connect to port 3360:

---
apiVersion: v1
kind: Service
metadata:
  name: mariadb-master
  namespace: example-mariadb
spec:
  type: NodePort
  selector:
    statefulset.kubernetes.io/example-mariadb: example-mariadb-0
  ports:
  - protocol: TCP
    port: 3360
    targetPort: 3360

Once you create that service in the same namespace, you can connect to MariaDB via the NodePort assigned to the service.

Development

Release Process

There are a few moving parts to this project:

1. The Docker image which powers MariaDB Operator.
2. The mariadb-operator.yaml Kubernetes manifest file which initially deploys the Operator into a cluster.

Each of these must be appropriately built in preparation for a new tag:

Build a new release of the Operator for Docker Hub

Run the following command inside this directory:

operator-sdk build geerlingguy/mariadb-operator:0.0.3

Then push the generated image to Docker Hub:

docker push geerlingguy/mariadb-operator:0.0.3

Build a new version of the mariadb-operator.yaml file

Verify the build/chain-operator-files.yml playbook has the most recent version/tag of the Docker image, then run the playbook in the build/ directory:

ansible-playbook chain-operator-files.yml

After it is built, test it on a local cluster:

minikube start
minikube addons enable ingress
kubectl apply -f deploy/mariadb-operator.yaml
kubectl create namespace example-mariadb
kubectl apply -f deploy/crds/mariadb_v1alpha1_mariadb_cr.yaml
<test everything>
minikube delete

If everything is deployed correctly, commit the updated version and push it up to GitHub, tagging a new repository release with the same tag as the Docker image.

Testing

Local tests with Molecule and KIND

Ensure you have the testing dependencies installed (in addition to Docker):

pip install docker molecule openshift jmespath

Run the local molecule test scenario:

molecule test -s test-local

Local tests with minikube

TODO.

Authors

This operator is maintained by Jeff Geerling, author of Ansible for DevOps and Ansible for Kubernetes.