Add GitHub Actions workflow for PPA publishing

.github/workflows/publish_to_PPA.yml

@@ -0,0 +1,62 @@
+name: Publish to Launchpad PPA
+
+on:
+  push:
+    tags:
+      - 'v*'  # Triggers on tags like v1.0.0, v1.2.3-1, etc.
+  workflow_dispatch: # Allows manual trigger from GitHub UI
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+
+    env:
+      # UPDATE THESE VARIABLES
+      PPA_TARGET: "ppa:your-launchpad-handle/your-ppa-name"
+      MAINTAINER_NAME: "Apostolos Chalis"
+      MAINTAINER_EMAIL: "achalis@csd.auth.gr"
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Install Debian packaging tools
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            build-essential \
+            devscripts \
+            debhelper \
+            dh-make \
+            dput \
+            gnupg
+
+      - name: Import GPG key for signing
+        uses: crazy-max/ghaction-import-gpg@v6
+        with:
+          gpg_private_key: ${{ secrets.chalis_ppa_key }}
+          passphrase: ${{ secrets.chalis_ppa_key }}
+
+      - name: Configure Git and Debian environment
+        run: |
+          git config user.name "$MAINTAINER_NAME"
+          git config user.email "$MAINTAINER_EMAIL"
+          export DEBFULLNAME="$MAINTAINER_NAME"
+          export DEBEMAIL="$MAINTAINER_EMAIL"
+
+      - name: Build Debian Source Package
+        run: |
+          # Clean untracked files that might interfere with debuild
+          git clean -fdx -e .github
+
+          # Build source package (-S) and include upstream tarball (-sa)
+          # -k specifies the key ID/email to use for signing
+          debuild -S -sa -k"$MAINTAINER_EMAIL"
+
+      - name: Upload to Launchpad PPA via dput
+        run: |
+          # Find the generated .changes file in the parent directory
+          CHANGES_FILE=$(ls ../*_source.changes | head -n 1)
+
+          echo "Uploading $CHANGES_FILE to $PPA_TARGET..."
+          dput -f "$PPA_TARGET" "$CHANGES_FILE"