Set up CI for container builds

(squashed from ~10 commits)

.gitea/workflows/build-container.yml

@@ -0,0 +1,49 @@
+name: Build Container
+run-name: Build Container
+on: ["workflow-dispatch", "push"]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up docker
+        run: |
+          curl -fsSL https://get.docker.com -o get-docker.sh
+          sh get-docker.sh
+
+      - name: Set up qemu
+        uses: https://github.com/docker/setup-qemu-action@v2
+
+      - name: Set up Buildx
+        uses: https://github.com/docker/setup-buildx-action@v2
+
+      - name: Login to git.magmaus3.eu.org
+        uses: https://github.com/docker/login-action@v2
+        with:
+          registry: git.magmaus3.eu.org
+          username: ${{ secrets.PERSONAL_REG_USERNAME }}
+          password: ${{ secrets.PERSONAL_REG_TOKEN }}
+
+      - name: Login to codeberg.org
+        uses: https://github.com/docker/login-action@v2
+        with:
+          registry: codeberg.org
+          username: ${{ secrets.CODEBERG_REG_USERNAME }}
+          password: ${{ secrets.CODEBERG_REG_TOKEN }}
+
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Build and push
+        uses: https://github.com/docker/build-push-action@v4
+        env:
+          ACTIONS_RUNTIME_TOKEN: ''
+        with:
+          context: .
+          push: true
+          tags: |
+            codeberg.org/magmaus3/gmdprivateserver:latest
+            codeberg.org/magmaus3/gmdprivateserver:f48330b
+            git.magmaus3.eu.org/gdps.host/gmdprivateserver:latest
+            git.magmaus3.eu.org/gdps.host/gmdprivateserver:f48330b
+