build(docker): standardise docker build pipeline

Author: satterly

.github/workflows/docker.yml

@@ -1,16 +1,20 @@
-name: Docker Build and Push
+name: Docker
 
 on:
   push:
     branches: [ master, release/* ]
+    tags: [ '**' ]
+
+env:
+  SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
 
 jobs:
   build:
+    name: Build & Push
     runs-on: ubuntu-latest
     env:
-      REPOSITORY_URL: docker.pkg.github.com
-      IMAGE_NAME: ${{ github.repository }}/alerta-cli
-      SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+      REPOSITORY_URL: ghcr.io
+      IMAGE_NAME: ${{ github.repository_owner }}/alerta-cli
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -22,16 +26,18 @@ jobs:
         run: >-
           docker build
           -t $IMAGE_NAME
+          -t $REPOSITORY_URL/$IMAGE_NAME:$(cat VERSION)
           -t $REPOSITORY_URL/$IMAGE_NAME:${{ steps.vars.outputs.SHORT_COMMIT_ID }}
           -t $REPOSITORY_URL/$IMAGE_NAME:latest .
       - name: Docker Login
-        env:
-          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
-          DOCKER_PASSWORD: ${{ secrets.GITHUB_TOKEN }}
-        run: docker login $REPOSITORY_URL --username "$DOCKER_USERNAME" --password "$DOCKER_PASSWORD"
+        uses: docker/login-action@v1
+        with:
+          registry: ${{ env.REPOSITORY_URL }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Publish Image
         id: docker-push
-        run: docker push $REPOSITORY_URL/$IMAGE_NAME
+        run: docker push --all-tags $REPOSITORY_URL/$IMAGE_NAME
 
       - uses: act10ns/slack@v1
         with: