**Course Title:** Mastering NestJS: Building Scalable Server-Side Applications **Section Title:** Deployment and CI/CD Pipelines **Topic:** Setting up CI/CD pipelines with GitHub Actions or GitLab CI **Overview** Continuous Integration and Continuous Deployment (CI/CD) pipelines are essential for automating the build, test, and deployment of software applications. In this topic, we will explore how to set up CI/CD pipelines using GitHub Actions and GitLab CI, two popular tools for automating the software development process. **Why CI/CD Pipelines?** CI/CD pipelines offer several benefits, including: * **Faster Time-to-Market**: Automate the build, test, and deployment process to reduce the time it takes to get your application to market. * **Improved Quality**: Catch bugs and errors early in the development process to ensure higher quality software. * **Increased Efficiency**: Automate repetitive tasks to free up developer time for more strategic work. **Setting up GitHub Actions** GitHub Actions is a CI/CD platform that allows you to automate your build, test, and deployment process. Here's a step-by-step guide to setting up GitHub Actions: 1. **Create a new GitHub Actions workflow**: Go to your repository settings and click on "Actions" in the left-hand menu. Click on "New workflow" and select "Set up a workflow yourself". 2. **Choose a trigger**: Select the trigger that will start your workflow, such as a push to a specific branch or a pull request. 3. **Add jobs**: Define the jobs that will run as part of your workflow. For example, you might have a job for building and testing your application, and another job for deploying it to production. 4. **Add steps**: Define the steps that will run as part of each job. For example, you might have a step for running a build script, and another step for running tests. 5. **Save and commit**: Save your workflow and commit it to your repository. **Example GitHub Actions Workflow** Here's an example GitHub Actions workflow that builds and deploys a NestJS application: ```yaml name: Build and Deploy on: push: branches: - main jobs: build-and-deploy: runs-on: ubuntu-latest steps: - name: Checkout code uses: actions/checkout@v2 - name: Install dependencies run: npm install - name: Build application run: npm run build - name: Deploy to production uses: appleboy/ssh-action@v0 with: host: ${{ secrets.PRODUCTION_HOST }} username: ${{ secrets.PRODUCTION_USERNAME }} password: ${{ secrets.PRODUCTION_PASSWORD }} script: | npm run deploy ``` **Setting up GitLab CI** GitLab CI is another popular CI/CD platform that allows you to automate your build, test, and deployment process. Here's a step-by-step guide to setting up GitLab CI: 1. **Create a new GitLab CI configuration file**: Create a new file in your repository called `.gitlab-ci.yml`. 2. **Define the stages**: Define the stages that will run as part of your pipeline, such as `build`, `test`, and `deploy`. 3. **Define the jobs**: Define the jobs that will run as part of each stage. 4. **Define the steps**: Define the steps that will run as part of each job. 5. **Save and commit**: Save your configuration file and commit it to your repository. **Example GitLab CI Configuration** Here's an example GitLab CI configuration that builds and deploys a NestJS application: ```yaml stages: - build - test - deploy build: stage: build script: - npm install - npm run build test: stage: test script: - npm run test deploy: stage: deploy script: - ssh ${{ CI_DEPLOY_USER }}@${{ CI_DEPLOY_HOST }} "npm run deploy" ``` **Conclusion** In this topic, we explored how to set up CI/CD pipelines using GitHub Actions and GitLab CI. We covered the benefits of CI/CD pipelines, and provided step-by-step guides for setting up GitHub Actions and GitLab CI. We also provided example workflows and configurations to help you get started with automating your build, test, and deployment process. **What's Next?** In the next topic, we will explore how to manage environment variables and configurations in your NestJS application. **Leave a comment or ask for help if you have any questions or need further clarification on any of the concepts covered in this topic.**