Run a database

Contents

Overview

This section describes how to run an ephemeral Oracle database or MySQL database in your Kubernetes cluster using approaches suitable for sample or basic testing purposes.

NOTES:

  • The databases are configured with ephemeral storage, which means all information will be lost on any shutdown or pod failure.

  • The Oracle Database images are supported for non-production use only. For more details, see My Oracle Support note: Oracle Support for Database Running on Docker Doc ID 2216342.1.

Oracle database in Kubernetes

The following example shows how to set up an ephemeral Oracle database with the following attributes:

Attribute Value
Kubernetes namespace default
Kubernetes pod oracle-db
Kubernetes service name oracle-db
Kubernetes service port 1521
Kubernetes node port 30011
Image container-registry.oracle.com/database/enterprise:12.2.0.1-slim
DBA user (with full privileges) sys as sysdba
DBA password <password placeholder>
Database Domain (not the same as a WebLogic Domain) k8s
Database PDB devpdb
Database URL inside Kubernetes cluster (from any namespace) oracle-db.default.svc.cluster.local:1521/devpdb.k8s
Database URL outside Kubernetes cluster dns-name-that-resolves-to-node-location:30011/devpdb.k8s

  1. Get the operator source and put it in /tmp/weblogic-kubernetes-operator.

    For example:

    $ cd /tmp

    $ git clone --branch v4.2.13
 https://github.com/oracle/weblogic-kubernetes-operator.git

    NOTE: We will refer to the top directory of the operator source tree as /tmp/weblogic-kubernetes-operator; however, you can use a different location.

    For additional information about obtaining the operator source, see the Developer Guide Requirements.

  2. Ensure that you have access to the database image:

    • Use a browser to log in to https://container-registry.oracle.com, select Database -> enterprise, and accept the license agreement.

    • Get the database image:

      • In the local shell, docker login container-registry.oracle.com.
      • In the local shell, docker pull container-registry.oracle.com/database/enterprise:12.2.0.1-slim.

    • If your Kubernetes cluster nodes do not all have access to the database image in a local cache, then:

      • Deploy a Kubernetes docker secret to the default namespace with login credentials for container-registry.oracle.com: 
        kubectl create secret docker-registry docker-secret \
        --docker-server=container-registry.oracle.com \
        --docker-username=your.email@some.com \
        --docker-password=your-password \
        --docker-email=your.email@some.com \
        -n default
        Pass the name of this secret as a parameter to the start-db-service.sh in the following step using -s your-image-pull-secret.
      • Alternatively, copy the database image to each local Docker cache in the cluster.
      • For more information, see the FAQ, Cannot pull image.

      WARNING: The Oracle Database images are supported only for non-production use. For more details, see My Oracle Support note: Oracle Support for Database Running on Docker Doc ID 2216342.1.

  3. Create a secret named oracle-db-secret in the default namespace with your desired Oracle SYS DBA password in its password key.

    • For example: 
      $ kubectl -n default create secret generic oracle-db-secret \
  --from-literal='password=<password placeholder>'
      (Replace <password placeholder> with your desired password.)
    • Oracle Database passwords can contain upper case, lower case, digits, and special characters. Use only “_” and “#” as special characters to eliminate potential parsing errors for Oracle Database connection strings.

  4. Create a deployment using the database image:

    Use the sample script in /tmp/weblogic-kubernetes-operator/kubernetes/samples/scripts/create-oracle-db-service to create an Oracle database running in the deployment, oracle-db.

    $ cd /tmp/weblogic-kubernetes-operator/kubernetes/samples/scripts/create-oracle-db-service

    $ start-db-service.sh

    Notes:

    • Call start-db-service.sh -h to see how to customize the namespace, node port, secret name, etc.
    • Call stop-db-service.sh to shutdown and cleanup the oracle-db deployment.
    • To troubleshoot, use the kubectl describe pod DB_POD_NAME and kubectl logs DB_POD_NAME commands on the database pod.

MySQL database in Kubernetes

The following example shows how to set up an ephemeral MySQL database with the following attributes:

Attribute Value
Kubernetes namespace default
Kubernetes pod mysql-db
Kubernetes service name mysql-db
Kubernetes service port 3306
Image mysql:5.6
Root user (with full privileges) <user name placeholder>
Root password <password placeholder>
Database URL inside Kubernetes cluster (from any namespace) jdbc:mysql://mysql-db.default.svc.cluster.local:3306/mysql

Copy the following YAML into a file named mysql.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: mysql-db
  namespace: default
  labels:
    app: mysql-db
spec:
  terminationGracePeriodSeconds: 5
  containers:
  - image: mysql:5.6
    name: mysql
    env:
    - name: MYSQL_ROOT_USER
      valueFrom:
        secretKeyRef:
          name: mysql-secret
          key: root-user
    - name: MYSQL_ROOT_PASSWORD
      valueFrom:
        secretKeyRef:
          name: mysql-secret
          key: root-password
    ports:
    - containerPort: 3306
      name: mysql
---
apiVersion: v1
kind: Service
metadata:
  name: mysql-db
  namespace: default
spec:
  ports:
  - port: 3306
  selector:
    app: mysql-db
  clusterIP: None
---
apiVersion: v1
kind: Secret
metadata:
  name: mysql-secret
  namespace: default
data:
  root-user: <user name placeholder>
  root-password: <password placeholder>

In file mysql.yaml, replace <user name placeholder> and <password placeholder>, respectively, with the output from piping the root user name and password through base64:

echo -n <user name placeholder> | base64
echo -n <password placeholder> | base64

Deploy MySQL using the command kubectl create -f mysql.yaml.

To shut down and clean up the resources, use kubectl delete -f mysql.yaml.