Add docker image generation action

.github/workflows/publish_image.yml

@@ -0,0 +1,62 @@
+name: Publish Docker image to GitHub Packages
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Set up Docker Buildx
+        id: buildx
+        continue-on-error: false # this process is prone to failure, lets repeat it again if fails
+        uses: docker/setup-buildx-action@v3
+      - name: Docker Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }} # github username or org
+          password: ${{ secrets.GITHUB_TOKEN }} # github actions builtin token. repo has to have pkg access.
+      - name: Prepare
+        id: prep
+        run: echo "created=$(date -u +'%Y-%m-%dT%H:%M:%SZ')" >> $GITHUB_OUTPUT
+      - name: Build and push armbian-router Docker image for linux/amd64
+        id: docker_build
+        continue-on-error: false
+        timeout-minutes: 40
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/amd64
+          pull: true
+          push: true
+          labels: |
+            org.opencontainers.image.title=${{ github.repository }}
+            org.opencontainers.image.description=${{ github.event.repository.description }}
+            org.opencontainers.image.url=${{ github.event.repository.html_url }}
+            org.opencontainers.image.source=${{ github.event.repository.clone_url }}
+            org.opencontainers.image.created=${{ steps.prep.outputs.created }}
+            org.opencontainers.image.revision=${{ github.sha }}
+            org.opencontainers.image.licenses=${{ github.event.repository.license.spdx_id }}
+          tags: ghcr.io/${{ github.repository }}:latest
+      #- name: Generate artifact attestation
+      #  uses: actions/attest-build-provenance@v2
+      #  with:
+      #    subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
+      #    subject-digest: ${{ steps.push.outputs.digest }}
+      #    push-to-registry: true
+