allow to run docker ci manually by entering a branch name

date time will be used so multiple images can be built and publish per branch.

.github/workflows/docker-custom.yaml

@@ -0,0 +1,80 @@
+# This workflow builds docker images on given custom 'branch name'.
+name: Custom Docker
+
+# Limit concurrent runs of this workflow within a single PR
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+on:
+  workflow_dispatch:
+    inputs:
+      branch_name:
+        type: string
+        description: 'Used to publish a hydra-node-{datetime}-{branch_name} docker image'
+        required: true
+        default: "master"
+
+permissions:
+  packages: write
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+    - name: 📥 Checkout repository
+      uses: actions/checkout@v4
+      with:
+        ref: ${{ github.event.inputs.branch_name }}
+
+    - name: 🐳 Login to GitHub Container Registry
+      uses: docker/login-action@v3
+      with:
+        registry: ghcr.io
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: ❄ Prepare nix
+      uses: cachix/install-nix-action@v30
+      with:
+        extra_nix_config: |
+          accept-flake-config = true
+          log-lines = 1000
+
+    - name: ❄ Cachix cache of nix derivations
+      uses: cachix/cachix-action@v15
+      with:
+        name: cardano-scaling
+        authToken: '${{ secrets.CACHIX_CARDANO_SCALING_AUTH_TOKEN }}'
+
+    - name: 🔨 Build image using nix
+      run: |
+        IMAGE_NAME=ghcr.io/${{github.repository_owner}}/hydra-node
+        echo "IMAGE_NAME=${IMAGE_NAME}" >> $GITHUB_ENV
+        nix build .#docker-hydra-node
+        ./result | docker load
+        
+        VERSION_NAME=${{github.ref_name}}
+
+        BRANCH_NAME="${{ github.event.inputs.branch_name }}"
+        [[ -z "${BRANCH_NAME}" ]] && { echo "branch_name is required"; exit 1; }
+            
+        DATETIME=$(date '+%Y%m%d%H%M')
+        CUSTOM_TAG="${DATETIME}-${BRANCH_NAME}"
+        echo "CUSTOM_TAG=${CUSTOM_TAG}" >> $GITHUB_ENV
+        
+        # Use 'FROM' instruction to use docker build with --label
+        echo "FROM hydra-node" | docker build \
+          --label org.opencontainers.image.source=https://github.com/cardano-scaling/hydra \
+          --label org.opencontainers.image.licenses=Apache-2.0 \
+          --label org.opencontainers.image.created=$(date -Is) \
+          --label org.opencontainers.image.revision=${{github.sha}} \
+          --label org.opencontainers.image.version=${VERSION_NAME:-unstable} \
+          --tag ${IMAGE_NAME}:${CUSTOM_TAG} -
+        
+        docker images
+        docker inspect ${IMAGE_NAME}:${CUSTOM_TAG}
+
+    - name: 📤 Push to registry
+      run: |
+        docker push "${IMAGE_NAME}:${CUSTOM_TAG}"