chore(ci): Build modified backends on PR (#6086)

* chore(stablediffusion-ggml): rm redundant comment

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* chore(ci): Build modified backends on PR

Signed-off-by: Richard Palethorpe <io@richiejp.com>

---------

Signed-off-by: Richard Palethorpe <io@richiejp.com>

.github/workflows/backend_build.yml

@@ -55,9 +55,9 @@ on:
         type: string
     secrets:
       dockerUsername:
-        required: true
+        required: false
       dockerPassword:
-        required: true
+        required: false
       quayUsername:
         required: true
       quayPassword:
@@ -66,6 +66,8 @@ on:
 jobs:
   backend-build:
     runs-on: ${{ inputs.runs-on }}
+    env:
+        quay_username: ${{ secrets.quayUsername }}
     steps:
 
 
@@ -187,7 +189,7 @@ jobs:
           password: ${{ secrets.dockerPassword }}
 
       - name: Login to Quay.io
-        # if: github.event_name != 'pull_request'
+        if: ${{ env.quay_username != '' }}
         uses: docker/login-action@v3
         with:
           registry: quay.io
@@ -230,7 +232,7 @@ jobs:
           file: ${{ inputs.dockerfile }}
           cache-from: type=gha
           platforms: ${{ inputs.platforms }}
-          push: true
+          push: ${{ env.quay_username != '' }}
           tags: ${{ steps.meta_pull_request.outputs.tags }}
           labels: ${{ steps.meta_pull_request.outputs.labels }}
 
@@ -238,4 +240,4 @@ jobs:
 
       - name: job summary
         run: |
-          echo "Built image: ${{ steps.meta.outputs.labels }}" >> $GITHUB_STEP_SUMMARY 
+          echo "Built image: ${{ steps.meta.outputs.labels }}" >> $GITHUB_STEP_SUMMARY

.github/workflows/backend_pr.yml

@@ -0,0 +1,58 @@
+name: 'build backend container images (PR-filtered)'
+
+on:
+  pull_request:
+
+concurrency:
+  group: ci-backends-pr-${{ github.head_ref || github.ref }}-${{ github.repository }}
+  cancel-in-progress: true
+
+jobs:
+  generate-matrix:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+      has-backends: ${{ steps.set-matrix.outputs.has-backends }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
+
+      - name: Install dependencies
+        run: |
+          bun add js-yaml
+          bun add @octokit/core
+
+      # filters the matrix in backend.yml
+      - name: Filter matrix for changed backends
+        id: set-matrix
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_EVENT_PATH: ${{ github.event_path }}
+        run: bun run scripts/changed-backends.js
+
+  backend-jobs:
+    needs: generate-matrix
+    uses: ./.github/workflows/backend_build.yml
+    if: needs.generate-matrix.outputs.has-backends == 'true'
+    with:
+      tag-latest: ${{ matrix.tag-latest }}
+      tag-suffix: ${{ matrix.tag-suffix }}
+      build-type: ${{ matrix.build-type }}
+      cuda-major-version: ${{ matrix.cuda-major-version }}
+      cuda-minor-version: ${{ matrix.cuda-minor-version }}
+      platforms: ${{ matrix.platforms }}
+      runs-on: ${{ matrix.runs-on }}
+      base-image: ${{ matrix.base-image }}
+      backend: ${{ matrix.backend }}
+      dockerfile: ${{ matrix.dockerfile }}
+      skip-drivers: ${{ matrix.skip-drivers }}
+      context: ${{ matrix.context }}
+    secrets:
+      quayUsername: ${{ secrets.LOCALAI_REGISTRY_USERNAME }}
+      quayPassword: ${{ secrets.LOCALAI_REGISTRY_PASSWORD }}
+    strategy:
+      fail-fast: true
+      matrix: ${{ fromJson(needs.generate-matrix.outputs.matrix) }}