Update Docker workflow for private image publishing

Author: BuxtonCalvin

.github/workflows/docker-private.yml

@@ -1,30 +1,42 @@
-name: Docker Private
+name: Publish Docker Private Image
+
 on:
-  [workflow_dispatch]
+  push:
+    branches:
+      - TSDB_dev
+  workflow_dispatch: 
 
 jobs:
- push:
-
+  build-and-push:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Checkout code
+        uses: actions/checkout@v4
+      
+      - name: Prepare Docker Metadata
+        id: prep
+        run: |
+          REPO_LC=$(echo "${{ github.event.repository.name }}" | tr '[:upper:]' '[:lower:]')
+          echo "repo=${REPO_LC}" >> $GITHUB_OUTPUT
+          echo "date=$(date +'%Y-%m-%d')" >> $GITHUB_OUTPUT        
 
-      - name: Get current date for tag
-        id: date
-        run: echo "NOW=$(date +'%Y-%m-%d')" >> $GITHUB_OUTPUT
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_TOKEN }}
 
-      - name: Log into registry
-        run: docker login -u ${{ secrets.DOCKER_USERNAME }} -p ${{ secrets.DOCKER_TOKEN }}
-      
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3      
- 
+        uses: docker/setup-buildx-action@v3
+
       - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with:
           context: .
           push: true
+          # This builds once and applies both tags to a single image
           tags: |
-            buxtoncalvin/ppg:latest
-            buxtoncalvin/ppg:${{ steps.date.outputs.NOW }}
+            ${{ secrets.DOCKER_USERNAME }}/ppg:latest
+            ${{ secrets.DOCKER_USERNAME }}/ppg:${{ steps.prep.outputs.date }}
+