In the previous two tutorials we covered how to setup local Kubernetes (Minikube) and deploy a SpringBoot application. You can find these tutorials below.<\/p>\n
In this tutorial, we would now cover how to deploy SpringBoot application with MySQL database. In this case, we would take the following steps:<\/p>\n
We would cover the following sub-topics:<\/p>\n
<\/p>\n
This deployment file for MySQL would be used to setup MySQL in the Kubernetes cluster. It would pull the MySQL image from the local or remote repository, create a new database, and spin up the container inside the cluster. This deployment file would have three parts: Service, PersistentVolumeClaim and Deployment.<\/p>\n
Service<\/strong><\/p>\n As you already know, the service is used to expose the deployment and make it accessible from outside and from other pods. The service part of the mysql-deployment.yaml<\/em> <\/strong>file is given below: <\/p>\n PersistentVolumeClaim<\/strong><\/p>\n A PersistentVolume is a piece of storage provided in a cluster either dynamically or by an administrator.<\/p>\n A PersistentVolumeClaim(PVC) is a request for storage (PV) by a user. Think of it as a pod made specially for providing storage space for other pods.<\/p>\n The PVC is defined in the MySQL deployment file. This is specified in the deployment file as follows:<\/p>\n <\/p>\n Deployment<\/strong><\/p>\n The actual deployment specification is given below:<\/p>\n <\/p>\n I would recommend you watch to video tutorial in my YouTube Channel<\/a> for a more detailed explanation of\u00a0 the various part of the deployment file. The complete mysql-deployment.yaml file can be found here.<\/a><\/p>\n <\/p>\n You now need to actually apply the deployment using the command below.<\/p>\n This command would deploy the service and spin up the containers (pods) in Minikube.<\/p>\n You can then verify that the pods are created using the kubectl get pods<\/em><\/strong> command<\/p>\n Access the MySQL Database inside the cluster<\/strong><\/p>\n Now that the MySQL is deployed, we would like to connect to the node right inside the cluster. You can use the command below:<\/p>\n Then use the command below to connect to the MySQL server.<\/p>\n <\/p>\n We need to modify the application.properties file so that instead of using the hardcoded environment variables for the database, we need to make the values dynamic. So in this case, we can connect to the MySQL port running inside the cluster.<\/p>\n You actually only need to change the username, password and url like so:<\/p>\n The useSSL=false line indicates that the database server need not be verified.<\/p>\n <\/p>\n Similar to the mysql-deployment, the app-deployment would contain two parts: the service and the deployment. These are shown below:<\/p>\n the deployment part<\/strong><\/p>\n The deployment part of the app-deployment.yaml file is given below:<\/p>\n <\/p>\n the service part<\/strong><\/p>\n The service part of the file is given below:<\/p>\n <\/p>\n Now\u00a0 that you have the app-deployment.yaml, you can apply the deployment using the command below after you navigate to the resources folder:<\/p>\n <\/p>\n You can then access the application using the node ip (from minikube ip<\/strong><\/em> command) and the node port (from kubectl get services<\/strong><\/em> command)<\/p>\n
\n<\/p>\n# Define a 'Service' To Expose MySQL to Other Services<\/span>\r\napiVersion: v1\r\nkind: Service\r\nmetadata:\r\n name: mysql\r\n labels:\r\n app: mysql\r\n tier: database\r\nspec:\r\n ports:\r\n - port: 3307\r\n targetPort: 3307\r\n selector:\r\n app: mysql\r\n tier: database\r\n clusterIP: None # DNS is used, so clusterIP is not needed<\/span>\r\n<\/pre>\n# Define a 'Persistent Volume Claim'(PVC) for MySQL Storage, dynamically provisioned by cluster<\/span>\r\napiVersion: v1\r\nkind: PersistentVolumeClaim\r\nmetadata:\r\n name: mysql-pv-claim # name of PVC essential for identifying the storage data<\/span>\r\n labels:\r\n app: mysql\r\n tier: database\r\nspec:\r\n accessModes:\r\n - ReadWriteOnce #This specifies the mode of the claim that we are trying to create.<\/span>\r\n resources:\r\n requests:\r\n storage: 1Gi #This will tell kubernetes about the amount of space we are trying to claim.<\/span>\r\n<\/pre>\n# Deployment specification begins here<\/span>\r\napiVersion: apps\/v1\r\nkind: Deployment\r\nmetadata:\r\n name: mysql\r\n labels:\r\n app: mysql\r\n tier: database\r\nspec:\r\n selector: # mySQL Pod Should contain same labels<\/span>\r\n matchLabels:\r\n app: mysql\r\n strategy:\r\n type: Recreate\r\n template:\r\n metadata:\r\n labels: # Must match 'Service' and 'Deployment' selectors<\/span>\r\n app: mysql\r\n tier: database\r\n spec:\r\n containers:\r\n - name: mysql\r\n image: mysql\r\n imagePullPolicy: \"IfNotPresent\"<\/span>\r\n env:\r\n - name: MYSQL_ROOT_PASSWORD\r\n value: root\r\n - name: MYSQL_DATABASE\r\n value: fleetdb\r\n ports:\r\n - containerPort: 3307\r\n name: mysql\r\n volumeMounts:\r\n - mountPath: \/var\/lib\/mysql\r\n name: mysql-persistance-storage\r\n volumes:\r\n - name: mysql-persistance-storage\r\n persistentVolumeClaim:\r\n claimName: mysql-pv-claim\r\n<\/pre>\n2. Test the MySQL Deployment<\/strong><\/h4>\n
kubectl apply -f mysql-deployment.yaml\r\n<\/pre>\n
kubectl exec -it <pod_name> bash\r\n<\/pre>\n
mysql -h mysql -u root -p \r\n<\/pre>\n
3. Modify the Application Properties File<\/strong><\/h4>\n
spring.datasource.password=${DB_USERNAME}\r\nspring.datasource.username=${DB_PASSWORD}\r\nspring.datasource.url=jdbc:mysql:\/\/${DB_HOST}\/${DB_NAME}?useSSL=false\r\n<\/pre>\n4. Create the Application Deployment<\/strong><\/h4>\n
---<\/span>\r\napiVersion: apps\/v1\r\nkind: Deployment\r\nmetadata:\r\n name: fleetms-v2\r\nspec:\r\n selector:\r\n matchLabels:\r\n app: fleetms-v2\r\n replicas: 3\r\n template:\r\n metadata:\r\n labels:\r\n app: fleetms-v2\r\n spec:\r\n containers:\r\n - name: fleetms-v2\r\n image: fleetms-v2:1.0\r\n ports:\r\n - containerPort: 8080\r\n env: # Setting Environmental Variables<\/span>\r\n - name: DB_HOST # Setting Database host address<\/span>\r\n value: mysql\r\n - name: DB_NAME # Setting Database name<\/span>\r\n value: fleetdb\r\n - name: DB_USERNAME # Setting Database username<\/span>\r\n value: root\r\n - name: DB_PASSWORD # Setting Database password<\/span>\r\n value: root\r\n# This seperator --- below is MANDATORY!!!<\/span>\r\n---<\/span>\r\n<\/pre>\n# Define a 'Service' To Expose the application<\/span>\r\napiVersion: v1\r\nkind: Service\r\nmetadata:\r\n name: fleetms-service\r\nspec:\r\n ports:\r\n - protocol: \"TCP\"<\/span>\r\n port: 8080 # Port inside the cluster<\/span>\r\n targetPort: # Port exposed to the outside<\/span>\r\n selector:\r\n app: fleetms-v2\r\n type: NodePort\r\n<\/pre>\n5. Deploy and Test the Application<\/strong><\/h4>\n
kubectl apply -f app-deployment.yaml\r\n<\/pre>\n