DevOps Project: CI/CD Pipeline for a Microservices-Based Application on Kubernetes

Table of Contents

1. Overview
2. Project Architecture
3. Step 1: Setting Up Microservices Repositories
   • 1.1 Create Repositories
   • 1.2 Microservices Structure
   • 1.3 Cloning Repositories
4. Step 2: Implementing CI/CD with Jenkins
   • 2.1 Jenkins Setup
   • 2.2 Creating Jenkinsfile for CI/CD
5. Step 3: Containerizing Microservices with Docker
   • 3.1 Creating Dockerfile for Each Service
   • 3.2 Building and Pushing Docker Images
6. Step 4: Deploying to Kubernetes
   • 4.1 Setting Up Kubernetes Cluster
   • 4.2 Creating Kubernetes Manifests
   • 4.3 Applying Manifests
7. Step 5: Implementing Monitoring with Prometheus and Grafana
   • 5.1 Installing Prometheus and Grafana
   • 5.2 Configuring Prometheus to Scrape Kubernetes Metrics
   • 5.3 Accessing Grafana Dashboard
8. Step 6: Implementing Logging with ELK Stack
   • 6.1 Deploying ELK Stack on Kubernetes
   • 6.2 Configuring Logstash to Collect Kubernetes Logs
   • 6.3 Accessing Kibana Dashboard
9. Conclusion
10. Final Thoughts

Overview

This project will guide you through setting up an end-to-end CI/CD pipeline for a microservices-based application. You will learn how to build, deploy, monitor, and log a microservices architecture using Jenkins, Docker, Kubernetes, Prometheus, Grafana, and the ELK Stack.

Project Architecture

The project consists of the following components:

• Microservices: User Service, Order Service, Payment Service.
• Jenkins: For continuous integration and deployment.
• Docker: For containerization of services.
• Kubernetes: For orchestrating the deployment.
• Prometheus & Grafana: For monitoring and observability.
• ELK Stack: For logging and log management.

Step 1: Setting Up Microservices Repositories

1.1. Create Repositories

You need to create three separate Git repositories for each microservice:

• user-service
• order-service
• payment-service

1.2. Microservices Structure

Each repository should have the following directory structure:

- src/
  - main/
    - java/
    - resources/
- Dockerfile
- Jenkinsfile
- pom.xml (for Maven projects) or package.json (for Node.js projects)

This structure ensures consistency across services and facilitates the CI/CD process.

1.3. Cloning Repositories

To get started, clone each repository to your local machine:

git clone https://github.com/SelimHorri/ecommerce-microservice-backend-app/user-service
git clone https://github.com/SelimHorri/ecommerce-microservice-backend-app/order-service
git clone https://github.com/SelimHorri/ecommerce-microservice-backend-app/payment-service

Step 2: Implementing CI/CD with Jenkins

2.1. Jenkins Setup

Jenkins is a key component in our CI/CD pipeline. Follow these steps to set it up:

1. Install Jenkins:

   wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add -
   sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'
   sudo apt-get update
   sudo apt-get install jenkins

1. Start Jenkins:

   sudo systemctl start jenkins

1. Access Jenkins:
   Open http://localhost:8080 in your browser to access the Jenkins dashboard.

2. Install Required Plugins:

   • Navigate to Manage Jenkins > Manage Plugins.
   • Install the following plugins:
     • Docker Pipeline Plugin
     • Kubernetes Plugin
     • Git Plugin

2.2. Creating Jenkinsfile for CI/CD

Each microservice should have a Jenkinsfile in its repository to define the CI/CD pipeline.

Example Jenkinsfile:

pipeline {
    agent any
    stages {
        stage('Checkout') {
            steps {
                git 'https://github.com/yourusername/user-service.git'
            }
        }
        stage('Build') {
            steps {
                sh 'mvn clean package'
            }
        }
        stage('Docker Build & Push') {
            steps {
                script {
                    dockerImage = docker.build("yourdockerhub/user-service:${env.BUILD_ID}")
                    docker.withRegistry('https://index.docker.io/v1/', 'dockerhub-credentials') {
                        dockerImage.push("${env.BUILD_ID}")
                        dockerImage.push("latest")
                    }
                }
            }
        }
        stage('Deploy to Kubernetes') {
            steps {
                sh 'kubectl apply -f kubernetes/deployment.yaml'
            }
        }
    }
}

This Jenkinsfile automates the build, Docker image creation, and deployment to Kubernetes.

Step 3: Containerizing Microservices with Docker

3.1. Creating Dockerfile for Each Service

Each microservice requires a Dockerfile to define how the container image is built.

Example Dockerfile (for a Java-based service):

# Use an official Java runtime as a parent image
FROM openjdk:11-jre-slim

# Set the working directory in the container
WORKDIR /app

# Copy the jar file into the container
COPY target/user-service.jar /app/user-service.jar

# Run the jar file
ENTRYPOINT ["java", "-jar", "/app/user-service.jar"]

# Expose the port the application runs on
EXPOSE 8080

3.2. Building and Pushing Docker Images

After creating the Dockerfile, build and push the Docker images to Docker Hub.

docker build -t yourdockerhub/user-service:latest .
docker push yourdockerhub/user-service:latest

Repeat the process for the order-service and payment-service.

Step 4: Deploying to Kubernetes

4.1. Setting Up Kubernetes Cluster

You can choose to deploy the application on a local Kubernetes cluster using Minikube or on AWS EKS for a production environment.

Minikube Setup:

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube
minikube start

EKS Setup (requires AWS CLI):

aws eks --region us-west-2 create-cluster --name DevOpsCluster --role-arn arn:aws:iam::YOUR_ACCOUNT_ID:role/EKSRole --resources-vpc-config subnetIds=subnet-0123456789abcdef0,subnet-abcdef0123456789

4.2. Creating Kubernetes Manifests

Create deployment and service manifests for each microservice.

Example Deployment Manifest (deployment.yaml):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: user-service
spec:
  replicas: 3
  selector:
    matchLabels:
      app: user-service
  template:
    metadata:
      labels:
        app: user-service
    spec:
      containers:
      - name: user-service
        image: yourdockerhub/user-service:latest
        ports:
        - containerPort: 8080

Example Service Manifest (service.yaml):

apiVersion: v1
kind: Service
metadata:
  name: user-service
spec:
  type: NodePort
  selector:
    app: user-service
  ports:
    - port: 8080
      targetPort: 8080


 nodePort: 30001

4.3. Applying Manifests

Deploy the microservices to the Kubernetes cluster using the following commands:

kubectl apply -f kubernetes/deployment.yaml
kubectl apply -f kubernetes/service.yaml

Repeat the process for the order-service and payment-service.

Step 5: Implementing Monitoring with Prometheus and Grafana

5.1. Installing Prometheus and Grafana

To install Prometheus and Grafana, use Helm, a package manager for Kubernetes.

helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo add grafana https://grafana.github.io/helm-charts
helm install prometheus prometheus-community/prometheus
helm install grafana grafana/grafana

5.2. Configuring Prometheus to Scrape Kubernetes Metrics

Configure Prometheus to scrape metrics from the Kubernetes cluster by editing the prometheus.yml file:

scrape_configs:
  - job_name: 'kubernetes'
    kubernetes_sd_configs:
      - role: node

5.3. Accessing Grafana Dashboard

Access Grafana at http://localhost:3000 and log in with the default credentials admin/admin. Import Prometheus as a data source and create dashboards to visualize metrics.

Step 6: Implementing Logging with ELK Stack

6.1. Deploying ELK Stack on Kubernetes

Deploy the ELK (Elasticsearch, Logstash, Kibana) stack using Helm:

helm repo add elastic https://helm.elastic.co
helm install elasticsearch elastic/elasticsearch
helm install kibana elastic/kibana
helm install logstash elastic/logstash

6.2. Configuring Logstash to Collect Kubernetes Logs

Create a Logstash configuration file to collect logs from Kubernetes:

input {
  beats {
    port => 5044
  }
}

output {
  elasticsearch {
    hosts => ["http://elasticsearch:9200"]
    index => "%{[@metadata][beat]}-%{+YYYY.MM.dd}"
  }
}

6.3. Accessing Kibana Dashboard

Access Kibana at http://localhost:5601 and visualize logs collected from Kubernetes.

Conclusion

In this project, you learned how to set up an end-to-end CI/CD pipeline for a microservices-based application, deploy it to Kubernetes, and monitor it using Prometheus, Grafana, and ELK Stack. This setup is highly scalable and provides a robust foundation for any microservices architecture.

Final Thoughts

This project is designed to provide a comprehensive learning experience for DevOps engineers. By following this guide, you'll gain hands-on experience with key DevOps tools and practices. For more detailed content and discussions, visit the full article on Dev.to.

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