GitHub Action Runner: deploy 2 environments (dev and prod) on a same server

I have a webserver and I want to deploy 2 environment: dev and prod on it. Don't understand how GitHub Actions works.

I have succeeded to deploy one environment (prod) but not both. I have 2 branches: one for the dev (it called "dev") and one for the prod (it called "main").

How do I suppose to do? Do I have to make a YAML file for each environment on their respective branches or do I have to write all deployments on the same file? How can I say for an environment to deploy a specific branch of my repository? On my webserver, do I have to deploy 2 services runner application or just 1 for both environment? How can I suppose to have both branches on _work directory?

This is my main.yaml file (runner) for only prod environment (it works):

name: Deployment

on:
  push:
    branches: [ "main" ]
  pull_request:
    branches: [ "main" ]

permissions:
  contents: read

jobs:
  build:
    runs-on: [self-hosted, linux]
    
    environment:
      name: myprod-environment
      url: https://www.mywebsite.com

    steps:
    - uses: actions/checkout@v3

    - name: Validate composer.json and composer.lock
      run: composer validate --strict

    - name: Cache Composer packages
      id: composer-cache
      uses: actions/cache@v3
      with:
        path: vendor
        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
        restore-keys: |
          ${{ runner.os }}-php-
    - name: Install dependencies
      run: composer install --prefer-dist --no-progress

I've tried to write a dev.yml on .github/workflows directory but I can't say for my github action runner service to deploy this environnment instead of main.yml.

I've also tried to add a new section on jobs into main.yml (like "build") but for dev deployment but even if I change the branch and I force the environnment to use a branch, it doesn't deploy both of jobs on _work directory.

That looks like a job for matrices

> Use jobs.<job_id>.strategy.matrix to define a matrix of different job configurations.
Within your matrix, define one or more variables followed by an array of values

But using non-primitive values in the matrix is not supported.
However, you can achieve the same goal using job outputs and a separate job for each environment.

That means using a single YAML file that handles both environments:

name: Deployment

on:
  push:
    branches:
      - main
      - dev

jobs:
  build:
    runs-on: [self-hosted, linux]

    steps:
    - name: Checkout repository
      uses: actions/checkout@v3

    - name: Print current branch
      run: echo "Current branch: ${{ github.ref }}"

    - name: Set deploy path and environment based on branch
      run: |
        if [ "${{ github.ref }}" == "refs/heads/main" ]; then
          echo "DEPLOY_PATH=/var/www/mywebsite/prod" >> $GITHUB_ENV
          echo "ENV_NAME=myprod-environment" >> $GITHUB_ENV
          echo "ENV_URL=https://www.mywebsite.com" >> $GITHUB_ENV
        elif [ "${{ github.ref }}" == "refs/heads/dev" ]; then
          echo "DEPLOY_PATH=/var/www/mywebsite/dev" >> $GITHUB_ENV
          echo "ENV_NAME=mydev-environment" >> $GITHUB_ENV
          echo "ENV_URL=https://dev.mywebsite.com" >> $GITHUB_ENV
        fi        

    - name: Configure environment
      echo "Environment:" ${{ env.ENV_NAME }}

    - name: Validate composer.json and composer.lock
      run: composer validate --strict

    - name: Cache Composer packages
      id: composer-cache
      uses: actions/cache@v3
      with:
        path: vendor
        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
        restore-keys: |
                    ${{ runner.os }}-php-

    - name: Install dependencies
      run: composer install --prefer-dist --no-progress

    - name: Deploy code to server
      run: |
        sudo chown -R your-user:your-group .
        sudo rsync -av --delete --exclude '.git' . ${{ env.DEPLOY_PATH }}        

That creates a single build job. The "Set deploy path and environment based on branch" step sets the DEPLOY_PATH, ENV_NAME, and ENV_URL environment variables based on the current branch.

That means you only need a single self-hosted runner on your web server.
When the workflow runs, it will create separate jobs for each environment and deploy the respective branches based on the configuration.

But that also supposes your server (Apache?, NGiNX?, ...) needs to be configured to serve both environments correctly, typically with:

• two folders (/var/www/mywebsite/prod, /var/www/mywebsite/dev)
• two virtual hosts, one for each folder

That is why the workflow has a DEPLOY_PATH env variable, and a step to copy the files to the appropriate directory on your server after the "Install dependencies" step.
The DEPLOY_PATH variable is then used in the "Deploy code to server" step.

Don't forget to replace your-user and your-group in the "Deploy code to server" step with the appropriate user and group for your server.