Add push image functionality to GitLab Migration Build Pipeline Workflow (#20)

* Initial plan

* Add push container functionality to GitLab migration workflow

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Fix version logic and improve workflow robustness

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Remove automatic triggers and keep only manual workflow dispatch

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Remove version input and rename workflow to build.yaml

Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>

* Remove tar artifacts and push images directly to GHCR

Co-authored-by: jenslehnhoff <1427862+jenslehnhoff@users.noreply.github.com>

* Remove unused CI=true build args and rename jobs to include push

Co-authored-by: jenslehnhoff <1427862+jenslehnhoff@users.noreply.github.com>

* Rename workflow from "Build Pipeline" to "Build & Push"

Co-authored-by: jenslehnhoff <1427862+jenslehnhoff@users.noreply.github.com>

* Rename workflow file from build.yaml to build-and-push.yaml

Co-authored-by: jenslehnhoff <1427862+jenslehnhoff@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: darthkali <46423967+darthkali@users.noreply.github.com>
Co-authored-by: jenslehnhoff <1427862+jenslehnhoff@users.noreply.github.com>

Author: 3 people

.github/workflows/build-and-push.yaml

@@ -0,0 +1,107 @@
+---
+name: Build & Push
+
+# Migrated from GitLab CI - supports manual dispatch
+"on":
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  # Build and push frontend container - migrated from build-container-ui
+  build-and-push-frontend:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set version
+        id: version
+        run: |
+          if [ "${{ github.ref_type }}" == "tag" ]; then
+            echo "VERSION=${{ github.ref_name }}" >> $GITHUB_ENV
+          else
+            echo "VERSION=${{ github.sha }}" >> $GITHUB_ENV
+          fi
+          echo "SHORT_SHA=${GITHUB_SHA:0:8}" >> $GITHUB_ENV
+          # Set image name for frontend
+          RAG_EVAL_UI_IMAGE="ghcr.io/${{ github.repository }}/rag-eval-ui"
+          echo "RAG_EVAL_UI_IMAGE=${RAG_EVAL_UI_IMAGE}" >> $GITHUB_ENV
+
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push frontend container
+        uses: docker/build-push-action@v6
+        with:
+          context: frontend/
+          file: frontend/Dockerfile
+          build-args: |
+            VERSION=${{ env.VERSION }}
+          push: true
+          tags: |
+            ${{ env.RAG_EVAL_UI_IMAGE }}:${{ env.SHORT_SHA }}
+            ${{ github.ref_type == 'tag' &&
+                format('{0}:{1}', env.RAG_EVAL_UI_IMAGE,
+                       github.ref_name) || '' }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+  # Build and push backend container - migrated from build-container-backend
+  build-and-push-backend:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set version
+        id: version
+        run: |
+          if [ "${{ github.ref_type }}" == "tag" ]; then
+            echo "VERSION=${{ github.ref_name }}" >> $GITHUB_ENV
+          else
+            echo "VERSION=${{ github.sha }}" >> $GITHUB_ENV
+          fi
+          echo "SHORT_SHA=${GITHUB_SHA:0:8}" >> $GITHUB_ENV
+          # Set image name for backend
+          LLM_EVAL_BACKEND_IMAGE="ghcr.io/${{ github.repository }}"
+          LLM_EVAL_BACKEND_IMAGE="${LLM_EVAL_BACKEND_IMAGE}/llm-eval-backend"
+          echo "LLM_EVAL_BACKEND_IMAGE=${LLM_EVAL_BACKEND_IMAGE}" >> \
+            $GITHUB_ENV
+
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push backend container
+        uses: docker/build-push-action@v6
+        with:
+          context: backend/
+          file: backend/Dockerfile
+          build-args: |
+            VERSION=${{ env.VERSION }}
+          push: true
+          tags: |
+            ${{ env.LLM_EVAL_BACKEND_IMAGE }}:${{ env.SHORT_SHA }}
+            ${{ github.ref_type == 'tag' &&
+                format('{0}:{1}', env.LLM_EVAL_BACKEND_IMAGE,
+                       github.ref_name) || '' }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max