Deploying the E-commerce website

For the initial MVP of deploying our application to Kubernetes, the following manifests were used.

Starting with the website Deployment spec, we set the environment variables accordingly.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecom-web
spec:
  replicas: 2
  selector:
    matchLabels:
      app: ecom-web
  template:
    metadata:
      labels:
        app: ecom-web
    spec:
      containers:
      - name: ecom-web
        image: ariyonaty/ecom-web:v1
        ports:
        - containerPort: 80
        env:
        - name: DB_HOST
          value: ecom-db
        - name: DB_USER
          value: ecomuser
        - name: DB_PASSWORD
          value: ecompassword
        - name: DB_NAME
          value: ecomdb

Additionally, we define a Service to expose the application.

apiVersion: v1
kind: Service
metadata:
  name: ecom-web
  labels:
    app: ecom-web
spec:
  ports:
  - port: 80
  selector:
    app: ecom-web

To quickly verify expected behavior, running a kubectl port-forward allows us to view the website locally.

kubectl --kubeconfig ~/.kube/talos-kubeconfig.yaml --insecure-skip-tls-verify port-forward services/ecom-web 8081:80

But wait - an error! error-without-db As shown above, our web app is unable to connect to our database. That makes sense though - we have yet to deploy the mariadb image to the Kubernetes cluster.

Let’s write that spec now. This will include several more resources.

Starting with the Service, we expose the MariaDB pod internal to the cluster. This also allows DNS lookups to the service name, ecom-db, like we specified in the ecom-web environment variable using DB_HOST.

---
apiVersion: v1
kind: Service
metadata:
  name: ecom-db
  labels:
    app: ecom-db
spec:
  ports:
    - port: 3306
  selector:
    app: ecom-db
  clusterIP: None

In the previous section, we defined the SQL initialization scripts for the database that were mounted as volumes via the Docker Compose into the container. This time, however, we define the data using ConfigMaps.

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: ecom-db-init-scripts
data:
  1_configure.sql: |
    CREATE USER 'ecomuser'@'%' IDENTIFIED BY 'ecompassword';
    GRANT ALL PRIVILEGES ON *.* TO 'ecomuser'@'%';
    FLUSH PRIVILEGES;

    CREATE DATABASE ecomdb;    

  2_db_load_script.sql: |+
    USE ecomdb;
    CREATE TABLE products (id mediumint(8) unsigned NOT NULL auto_increment,Name varchar(255) default NULL,Price varchar(255) default NULL, ImageUrl varchar(255) default NULL,PRIMARY KEY (id)) AUTO_INCREMENT=1;

    INSERT INTO products (Name,Price,ImageUrl) VALUES ("Laptop","100","c-1.png"),("Drone","200","c-2.png"),("VR","300","c-3.png"),("Tablet","50","c-5.png"),("Watch","90","c-6.png"),("Phone Covers","20","c-7.png"),("Phone","80","c-8.png"),("Laptop","150","c-4.png");

With the ConfigMaps defined, we can now reference them in the Deployment spec and mount it into the appropriate directory within the container/pod.

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ecom-db
  labels:
    app: ecom-db
spec:
  selector:
    matchLabels:
      app: ecom-db
  template:
    metadata:
      labels:
        app: ecom-db
    spec:
      containers:
      - image: mariadb
        name: mariadb
        volumeMounts:
        - mountPath: /docker-entrypoint-initdb.d
          name: ecom-db-cm-volume
        env:
        - name: MARIADB_ROOT_PASSWORD
          value: ecompassword
        ports:
        - containerPort: 3306
          name: mariadb
      volumes:
        - configMap:
            name: ecom-db-init-scripts
          name: ecom-db-cm-volume

Now after applying all the manifests, the website properly loads the data from the database. As an MVP, it works, but there’s certainly more work to do..