Add conditional trigger for backend workflow

* The build is triggered for a specific service only if its files have been changes

Author: McNaBry

.github/workflows/backend.yml

@@ -4,9 +4,6 @@ on:
   push:
     branches: [ 'main' ]
     paths: [ 'services/match/**', 'services/question/**', 'services/user/**' ]
-  pull_request:
-    branches: [ 'main' ]
-    types: [ 'opened', 'reopened', 'synchronize'] 
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
@@ -41,12 +38,9 @@ jobs:
             service:
               - '.services/${{ matrix.service }}/**'
 
-      - name: Exit if no changes found
-        if: steps.changes.output.service == 'false'
-        run: exit 0
-
       - name: Configure AWS credentials
         id: aws-configure
+        if: steps.changes.output.service == 'true'
         uses: aws-actions/[email protected]
         with:
           role-to-assume: ${{ secrets.AWS_BACKEND_ROLE }}
@@ -55,10 +49,12 @@ jobs:
 
       - name: Login to AWS ECR
         id: login-ecr
+        if: steps.changes.output.service == 'true'
         uses: aws-actions/[email protected]
 
-      - name: Build and push ${{ matrix.service }} image to Amazon ECR
+      - name: Build and push ${{ matrix.service }} image to AWS ECR
         id: build-image
+        if: steps.changes.output.service == 'true'
         env:
           ECR_REGISTRY: ${{ steps.login-ecr.outputs.registry }}
           ECR_REPOSITORY: ${{ matrix.service }}
@@ -70,6 +66,7 @@ jobs:
 
       - name: Update AWS Service (${{ matrix.service }}) # Trigger re-deployment with latest image
         id: update-service
+        if: steps.changes.output.service == 'true'
         env:
           ECS_SERVICE: ${{ matrix.service }}-service
         run: |