सारंग's Notes

3 Microservices Task

3 min read

1. Project Setup and Namespace Creation

Booting up EC2 and Cluster
  • Launch Ec2 instance
  • Add IAM Role
  • Install Docker and Kubernetes Packages
  • Create Cluster
Download Free css template
curl -O https://www.free-css.com/assets/files/free-css-templates/download/page296/neogym.zip
 
unzip neogym.zip
 
mv neogym-html/* html/

2. Microservice 1: Nginx with Free CSS Template

  • Dockerfile (Dockerfile_nginx):
FROM nginx:stable-alpine3.20-perl 
COPY ./html/ /usr/share/nginx/html/
EXPOSE 80
 
CMD ["/usr/bin/nginx", "-g", "daemon off;"]
  • Build and Push Docker Image:
# Build Image
docker build -t nginx-free-css:latest -f Dockerfile_nginx . 
# Add tag to repo-name/image name for docker hub push
docker tag nginx-css <repo-name>/nginx-css
# Push to docker hub repo
docker push nginx-free-css:latest
  • Create Kubernetes Namespaces: Create 3 Namespaces for 3 Microservices
kubectl create namespace dev-nginx
kubectl create namespace dev-httpd
kubectl create namespace dev-tomcat

Create Deployments

  • Kubernetes Deployment (dev-nginx namespace):
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deployment
      namespace: dev-nginx
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          containers:
          - name: nginx
            image: nginx-free-css:latest
            ports:
            - containerPort: 80
  • Apply Deployment:
kubectl apply -f nginx-deployment.yaml -n dev-nginx

3. Microservice 2: HTTP Server with ConfigMap

  • ConfigMap (dev-httpd namespace):
apiVersion: v1
kind: ConfigMap
metadata:
  name: index-html
  namespace: dev-httpd
data:
  index.html: |
    <!DOCTYPE html>
    <html>
    <head>
      <title>HTTP Server</title>
    </head>
    <body>
      <h1>Hello from HTTP Server!</h1>
    </body>
    </html>
  • Deployment (dev-httpd namespace):
apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpd-deployment
  namespace: dev-httpd
spec:
  replicas: 1
  selector:
    matchLabels:
      app: httpd
  template:
    metadata:
      labels:
        app: httpd
    spec:
      containers:
      - name: httpd
        image: httpd:latest 
        volumeMounts:
        - name: config-volume
          mountPath: /usr/local/apache2/htdocs/ 
      volumes:
      - name: config-volume
        configMap:
          name: index-html
  • Apply ConfigMap and Deployment:
kubectl apply -f index-html.yaml -n dev-httpd
kubectl apply -f httpd-deployment.yaml -n dev-httpd

4. Microservice 3: Tomcat

  • Deployment (dev-tomcat namespace):
apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat-deployment
  namespace: dev-tomcat
spec:
  replicas: 1
  selector:
    matchLabels:
      app: tomcat
  template:
    metadata:
      labels:
        app: tomcat
    spec:
      containers:
      - name: tomcat
        image: tomcat:latest
        ports:
        - containerPort: 8080
  • Apply Deployment:
kubectl apply -f tomcat-deployment.yaml -n dev-tomcat

5. Nginx Ingress Controller (nginx-ingress namespace)

  • Install Ingress Controller:
    • Refer to the official Nginx Ingress Controller documentation for installation instructions.

6. Ingress Configuration (nginx-ingress namespace)

  • Create Ingress resource:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: microservices-ingress
spec:
  rules:
  - host: httpd.your-domain.com 
    http:
      paths:
      - path: /
        pathType: Prefix 
        backend:
          service:
            name: httpd-service 
            port:
              number: 80
  - host: tomcat.your-domain.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: tomcat-service
            port:
              number: 8080
  - host: nginx.your-domain.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-service
            port:
              number: 80

  • Create Services for each Deployment:

    • You’ll need to create Services of type LoadBalancer or NodePort for each Deployment to expose them.

  • Apply Ingress and Services:

kubectl apply -f microservices-ingress.yaml -n nginx-ingress 
# Apply Service YAML files for each Deployment

7. DNS Configuration

  • Configure your DNS records to point the following domains to the Ingress Controller’s IP address:
    • httpd.your-domain.com
    • tomcat.your-domain.com
    • nginx.your-domain.com

8. Node Assignment (Manual)

  • Node 1: Schedule the httpd-deployment to run on Node 1.
  • Node 2: Schedule the tomcat-deployment to run on Node 2.
  • Node 3: Schedule the nginx-deployment to run on Node 3.

Note:

  • Replace placeholders like your-domain.com with actual domain names.
  • Adjust paths, ports, and other configurations as per your requirements.
  • This is a basic example. You may need to adjust the configurations based on your specific needs and security requirements.
  • Consider using a more robust service discovery mechanism like Kubernetes Service.
  • For production environments, use a more advanced deployment strategy like rolling updates or blue/green deployments.

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