chore: add pull request build (#557)

.github/workflows/pull_request.yml

@@ -0,0 +1,64 @@
+name: build-pullrequest
+on:
+  pull_request:
+    branches:
+      - live
+    paths-ignore:
+      - "**.md"
+jobs:
+  bluebuild:
+    name: PR build
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+    strategy:
+      fail-fast: false 
+      matrix:
+        recipe:
+          - general/recipe-silverblue-main-userns.yml
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Maximize build space
+        uses: jlumbroso/free-disk-space@54081f138730dfa15788a46383842cd2f914a1be # v1.3.1
+
+      - name: Determine Vars
+        id: build_vars
+        shell: bash
+        env:
+          RECIPE: ${{ matrix.recipe }}
+        run: |
+          RECIPE_PATH=""
+          if [ -f "./config/${RECIPE}" ]; then
+            RECIPE_PATH="./config/${RECIPE}"
+          else
+            RECIPE_PATH="./recipes/${RECIPE}"
+          fi
+          echo "recipe_path=${RECIPE_PATH}" >> ${GITHUB_OUTPUT}
+          
+      - name: Install BlueBuild
+        shell: bash
+        env:
+          CLI_VERSION_TAG: ${{ steps.build_vars.outputs.cli_version }}
+        run: |
+          docker create \
+            --name blue-build-installer \
+            ghcr.io/blue-build/cli:v0.8.20-installer
+          docker cp blue-build-installer:/out/bluebuild /usr/local/bin/bluebuild
+          docker rm blue-build-installer
+          bluebuild --version
+
+      - name: Build Image
+        shell: bash
+        working-directory: ${{ inputs.working_directory }}
+        env:
+          RECIPE_PATH: ${{ steps.build_vars.outputs.recipe_path }}
+          RUST_LOG_STYLE: always
+          CLICOLOR_FORCE: '1'
+          GH_PR_EVENT_NUMBER: ${{ github.event.number }}
+        run: |
+          BUILD_OPTS="--build-driver podman --squash"
+          bluebuild build -v ${BUILD_OPTS} ${RECIPE_PATH}
+