Add automatic deployment with GH Action (#2)

* Refactor build workflow to use our own docker-compose rules

* Upload website build as artifact

* Add a deploy job to build.yml workflow, triggering it only on push/merge to main

* Rename build.yml to build_and_deploy.yml

* Trigger deployment only if website sources have been modified

* Create and populate SSH Key and upload website build to remote server

.github/workflows/build_and_deploy.yml

@@ -0,0 +1,73 @@
+name: Build and deploy HUGO website
+
+on:
+  # Runs on pull requests to check that the website is building without errors
+  pull_request:
+
+  # Runs on push/merge to main to deploy the new website
+  # Only run if the push updates website sources
+  push:
+    paths:
+      - src/**
+    branches:
+      - main
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  # Build job
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      # Checkout repo AND ITS SUBMODULES
+      - name: 🛒 Checkout
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      # Build the static website with the provided docker-compose rules
+      - name: 🛠️ Build with HUGO
+        run: |
+          docker compose up builder
+
+      # Upload build artifacts for deployment or download
+      - name: 🚀 Upload Artifacts
+        uses: actions/upload-artifact@v3
+        with:
+          name: build
+          path: ./build/blog
+
+  # Deployment job: heavily inspired from https://swharden.com/blog/2022-03-20-github-actions-hugo/
+  # /!\ only triggers on push events
+  deploy:
+    needs: [build]
+    if: ${{ github.event_name == 'push' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: 🛠️ Setup build directory
+        run: |
+          mkdir -p build/blog
+      - name: 📥 Download build Artifacts
+        uses: actions/download-artifact@v3
+        with:
+          name: build
+          path: build/blog
+
+      # Create the SSH key file and fill the known_hosts to avoid a prompt from ssh (1st time connecting to remote host)
+      - name: 🔐 Create Key File
+        run: |
+          mkdir ~/.ssh
+          touch ~/.ssh/id_rsa
+          chmod 600 ~/.ssh/id_rsa
+      - name: 🔐 Load Host Keys
+        run: |
+          echo "${{ secrets.SSH_KNOWN_HOSTS }}" > ~/.ssh/known_hosts
+      - name: 🔑 Populate Key
+        run: |
+          echo "${{ secrets.PRIVATE_SSH_KEY }}" > ~/.ssh/id_rsa
+
+      # Finally upload the build to the remote server location: the volume shared by the nginx container serving http requests
+      - name: 🚀 Upload
+        run: |
+          rsync --archive --stats --verbose --delete ./build/blog/* ${{ secrets.CI_USER_NAME }}@iscsc.fr:${{ secrets.STATIC_WEBSITE_PATH}}