add: a workflow to check if docker containers can be built if the files are modified.

Author: sayakpaul

.github/workflows/test_docker_build.yml

@@ -0,0 +1,41 @@
+name: Test Docker images (scheduled)
+
+on:
+  pull_request:
+  paths:
+    # Run only when DockerFile files are modified
+    - "docker/**"
+
+concurrency:
+  group: docker-image-builds
+  cancel-in-progress: false
+
+jobs:
+  name: "Build all modified docker images"
+  runs-on: ubuntu-latest
+  steps:
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v1
+    - name: Check out code
+      uses: actions/checkout@v3
+    - name: Get changed files
+      id: changed-files
+      uses: tj-actions/changed-files@3f54ebb830831fc121d3263c1857cfbdc310cdb9 #v42
+      with:
+        files: docker/**
+    - name: Run step if only the files listed above change
+      if: steps.changed-files.outputs.only_changed == 'true'
+      env:
+        CHANGED_FILES: ${{ steps.changed-files.outputs.all_changed_files}}
+      run: |
+        for file in ${CHANGED_FILES}; do
+          echo "$file was changed"
+        done
+    - name: Build Docker images
+      strategy:
+        matrix:
+          docker-file: ${{ steps.changed-files.outputs.all_changed_files}}
+      uses: docker/build-push-action@v4
+      with:
+        context: ${{ matrix.docker-file }}
+        push: False