Switched from GITHUB_ENV to GITHUB_OUTPUT (step outputs)

I couldn’t find any official statement on which is the recommended approach.
But I did see this warning that says “set-output” is deprecated, switch to using environment files:
https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Note that this doesn’t say that “steps.output” is deprecated; it says “set-output” is deprecated.
So, step outputs are still valid and we essentially have to choose between: GITHUB_ENV and GITHUB_OUTPUT

One argument in favor of GITHUB_OUTPUT is this:
- This comment mentions that Environment variables are only available in the same job.
- https://github.com/orgs/community/discussions/55294#discussioncomment-5884935

- Github_Output documentation mentions that job outputs available to all dependent downstream jobs.
- https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/passing-information-between-jobs#:~:text=Job%20outputs%20are%20available%20to%20all%20downstream%20jobs%20that%20depend%20on%20this%20job

- Right now we do have just one job in the dashboard build workflows.
- But in the future if we have more jobs, then GITHUB_OUTPUT could be more suited.

.github/workflows/image_build_push.yml

@@ -2,7 +2,7 @@ name: docker-image-push-public-dash
 
 on:
   push:
-    branches: [ main ]
+    branches: [ main, cleanup-cicd ]
 
   workflow_dispatch:
     inputs:
@@ -17,60 +17,56 @@ env:
 jobs:
   build:
     runs-on: ubuntu-latest
-
-    env:
-      DOCKER_TAG_FROM_WORKFLOW_DISPATCH: ${{ github.event.inputs.docker_image_tag }}
 
     steps:
     - uses: actions/checkout@v4
 
-    - name: Set docker image tag from .env file
+    - name: Set docker image tags
+      id: set-tags
       run: |
         set -a; source .env; set +a
-        echo "Restoring latest server image tag from .env"
-        echo "DOCKER_TAG_FROM_PUSH=${SERVER_IMAGE_TAG}" >> $GITHUB_ENV
+        echo "DOCKER_TAG_FROM_PUSH=${SERVER_IMAGE_TAG}" >> "$GITHUB_OUTPUT"
+        echo "DOCKER_TAG_FROM_WORKFLOW_DISPATCH=${{ github.event.inputs.docker_image_tag }}" >> "$GITHUB_OUTPUT"
 
     - name: Set docker image tag from .env.repoTags file
+      id: set-frontend-tag
       run: |
         set -a; source .env.repoTags; set +a
-        echo "Restoring latest frontend image tag from .env.repoTags"
-        echo "FRONTEND_IMAGE_TAG=${FRONTEND_IMAGE_TAG}" >> $GITHUB_ENV
+        echo "FRONTEND_IMAGE_TAG=${FRONTEND_IMAGE_TAG}" >> "$GITHUB_OUTPUT"
 
     - name: Print input docker image tag
       run: |
         echo "Event name: ${{ github.event_name }}"
-        echo "Latest docker image tag (push): ${{ env.DOCKER_TAG_FROM_PUSH }}"
-        echo "Latest docker image tag (workflow_dispatch): ${{ env.DOCKER_TAG_FROM_WORKFLOW_DISPATCH }}"
-        echo "Current frontend image tag (push): ${{ env.FRONTEND_IMAGE_TAG }}"
+        echo "Latest docker image tag (push): ${{ steps.set-tags.outputs.DOCKER_TAG_FROM_PUSH }}"
+        echo "Latest docker image tag (workflow_dispatch): ${{ steps.set-tags.outputs.DOCKER_TAG_FROM_WORKFLOW_DISPATCH }}"
+        echo "Current frontend image tag (push): ${{ steps.set-frontend-tag.outputs.FRONTEND_IMAGE_TAG }}"
 
     - name: docker login
       run: | # log into docker hub account
         docker login -u $DOCKER_USER -p $DOCKER_PASSWORD
 
     - name: Get current date # get the date of the build
       id: date
-      run: echo "::set-output name=date::$(date +'%Y-%m-%d--%M-%S')"
+      run: echo "date=$(date +'%Y-%m-%d--%M-%S')" >> "$GITHUB_OUTPUT"
 
     - name: Run a one-line script
       run: echo running in repo ${GITHUB_REPOSITORY#*/} branch ${GITHUB_REF##*/} on ${{ steps.date.outputs.date }}
 
     - name: build docker image
       run: |
         if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
-          SERVER_IMAGE_TAG=$DOCKER_TAG_FROM_WORKFLOW_DISPATCH docker compose -f docker-compose.yml build
+          SERVER_IMAGE_TAG=${{ steps.set-tags.outputs.DOCKER_TAG_FROM_WORKFLOW_DISPATCH }} docker compose -f docker-compose.yml build
         else
-          SERVER_IMAGE_TAG=$DOCKER_TAG_FROM_PUSH docker compose -f docker-compose.yml build
+          SERVER_IMAGE_TAG=${{ steps.set-tags.outputs.DOCKER_TAG_FROM_PUSH }} docker compose -f docker-compose.yml build
         fi
         docker images
 
     - name: rename docker images
       run: |
         if [ "${{ github.event_name }}" == "push" ]; then
           docker image tag em-pub-dash-prod/frontend:latest $DOCKER_USER/${GITHUB_REPOSITORY#*/}_frontend:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
-          echo "FRONTEND_IMAGE_TAG=${{ steps.date.outputs.date }}" >> $GITHUB_ENV
         fi
         docker image tag em-pub-dash-prod/viz-scripts:latest $DOCKER_USER/${GITHUB_REPOSITORY#*/}_notebook:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
-        echo "NOTEBOOK_IMAGE_TAG=${{ steps.date.outputs.date }}" >> $GITHUB_ENV
 
     - name: push docker images
       run: |
@@ -83,7 +79,7 @@ jobs:
       run: |
         if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
           echo "Workflow_dispatch: New server image built and pushed, Updating image tag in .env"
-          echo "SERVER_IMAGE_TAG=$DOCKER_TAG_FROM_WORKFLOW_DISPATCH" > .env
+          echo "SERVER_IMAGE_TAG=${{ steps.set-tags.outputs.DOCKER_TAG_FROM_WORKFLOW_DISPATCH }}" > .env
         else
           echo "Push event: New frontend image built and pushed, Updating image tag in .env.repoTags"
           echo "FRONTEND_IMAGE_TAG=${{ steps.date.outputs.date }}" > .env.repoTags
@@ -103,8 +99,12 @@ jobs:
    
     - name: Create tag files
       run: |
-        echo ${{ env.FRONTEND_IMAGE_TAG }} > frontend_tag_file.txt
-        echo ${{ env.NOTEBOOK_IMAGE_TAG }} > notebook_tag_file.txt
+        if [ "${{ github.event_name }}" == "push" ]; then
+          echo ${{ steps.date.outputs.date }} > frontend_tag_file.txt
+        else
+          echo ${{ steps.set-frontend-tag.outputs.FRONTEND_IMAGE_TAG }} > frontend_tag_file.txt
+        fi
+        echo ${{ steps.date.outputs.date }} > notebook_tag_file.txt
         echo "Created tag text files"
 
     - name: Upload Frontend Tag Artifact