[codex] Switch image publishing to GHCR

.github/workflows/docker-image.yml

@@ -7,30 +7,42 @@ on:
   pull_request:
     branches: [ "main" ]
 
+permissions:
+  contents: read
+  packages: write
+
+env:
+  IMAGE_NAME: ghcr.io/sprocketbot/elo-service
+
 jobs:
 
   build:
 
     runs-on: ubuntu-latest
 
     steps:
+    - name: Check out repository
+      uses: actions/checkout@v4
+
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v2
 
-    - name: Log in to Docker Hub
+    - name: Log in to GitHub Container Registry
+      if: github.event_name != 'pull_request'
       uses: docker/login-action@v2
       with:
-        username: ${{ secrets.docker_username }}
-        password: ${{ secrets.docker_access_token }}
+        registry: ghcr.io
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
 
     - name: Extract branch name
       shell: bash
-      run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF#refs/heads/})"
+      run: echo "branch=${GITHUB_HEAD_REF:-${GITHUB_REF#refs/heads/}}" >> "$GITHUB_OUTPUT"
       id: extract_branch
 
     - name: Build And Push Image
       uses: docker/build-push-action@v3
       with:
-        push: true
-        tags: ${{secrets.docker_username}}/elo-service:${{ steps.extract_branch.outputs.branch }}
+        push: ${{ github.event_name != 'pull_request' }}
+        tags: ${{ env.IMAGE_NAME }}:${{ steps.extract_branch.outputs.branch }}
         platforms: linux/amd64