Possible to use conditional in the "env" section of a job?

[bagel-dawg]

I have several use cases where the environment variables for a job change depending on if I am on the master branch or not, or for example if the build up to the point has failed.

My code for sending a slack message based on build status looks something like this:

- name: Success Send Build Notification
  uses: rtCamp/action-slack-notify@v2.1.0
  if: github.ref == 'refs/heads/master' &&  success()
  env:
    SLACK_COLOR: "good"
    SLACK_USERNAME: "Github Actions"
    SLACK_ICON_EMOJI: ":ocotcat:"
    SLACK_TITLE: "This is a GitHub Actions build!"
    SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
    SLACK_CHANNEL: "#channel"
    SLACK_MESSAGE: "This build has passed!."

name: Failed Send Build Notification

uses: rtCamp/action-slack-notify@v2.1.0

if: github.ref == 'refs/heads/master' &&  failure()

env:

SLACK_COLOR: "danger"

SLACK_USERNAME: "Github Actions"

SLACK_ICON_EMOJI: ":ocotcat:"

SLACK_TITLE: "This is a GitHub Actions build!"

SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}

SLACK_CHANNEL: "#channel"

SLACK_MESSAGE: "This build has failed. :("

It would be much more convenient if I could instead combine this into a single code block which conditional env vars, something like this?

- name: Send Build Notification
  uses: rtCamp/action-slack-notify@v2.1.0
  if: github.ref == 'refs/heads/master' &&  success()
  env:
    SLACK_COLOR: "${{ job.status }} === 'success' ? 'good' : 'danger'"
    SLACK_USERNAME: "Github Actions"
    SLACK_ICON_EMOJI: ":ocotcat:"
    SLACK_TITLE: "This is a GitHub Actions build!"
    SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
    SLACK_CHANNEL: "#channel"
    SLACK_MESSAGE: "This job has ${{ job.status }} === 'success' ? 'passed!' : 'failed. :('"

Is there a way to do this, or perhaps another creative, compact way of accomplishing the same goal?

[Simran-B]

There is no support for a ternary operator, but there are workarounds. You can try the following:

- name: Send Build Notification
  uses: rtCamp/action-slack-notify@v2.1.0
  if: github.ref == 'refs/heads/master' &&  success()
  env:
    SLACK_COLOR: "${{ job.status == 'success' && 'good' || 'danger' }}"
    SLACK_USERNAME: "Github Actions"
    SLACK_ICON_EMOJI: ":ocotcat:"
    SLACK_TITLE: "This is a GitHub Actions build!"
    SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}
    SLACK_CHANNEL: "#channel"
    SLACK_MESSAGE: "This job has ${{ job.status == 'success' && 'passed!' || 'failed. :(' }}"

A limitation here is that the value after && must not be falsey, because in that case the || (or) branch would be taken incorrectly. Not a problem here however, because it’s not an empty string or the like.

Another pseudo ternary expression that I haven’t tested yet, but which should work in principle and doesn’t suffer from above limitation:

fromJSON('["danger", "good"]')[job.status == 'success']

This relies on type coercion, an implicit cast from boolean true to 1 or false to 0, which is then used as array index. As array literals aren’t supported (yet), fromJSON() is required to construct the array.

[devSajan]

when creating this variable it's not working
FILE_PATH: "${{ env.ACT && '$HOME/file_path' || '/home/file_path' }}"
I am getting FILE_PATH value as $HOME/file_path instead of /home/user/file_path
how can i do that?

[BrightRan]

@bagel-dawg,

Possible to use conditional in the “env” section of a job?

This is not supported currently.

As a workaround, you can try to configure your workflow like as below:

jobs:
  build:
    . . .
send_slack_msg:

needs: [build]

if: ${{ github.ref == 'refs/heads/master' && always() }}

runs-on: ubuntu-latest

steps:

- name: Set environment variables

run: |

echo "SLACK_USERNAME=Github Actions" >> $GITHUB_ENV

echo "SLACK_ICON_EMOJI=:ocotcat:" >> $GITHUB_ENV

echo "SLACK_TITLE=This is a GitHub Actions build!" >> $GITHUB_ENV

echo "SLACK_WEBHOOK=${{ secrets.SLACK_WEBHOOK }}" >> $GITHUB_ENV

echo "SLACK_CHANNEL=#channel" >> $GITHUB_ENV
      if [[ ${{ needs.build.result }} == success ]]; then
        echo "SLACK_COLOR=good" >> $GITHUB_ENV
        echo "SLACK_MESSAGE=This build has passed!" >> $GITHUB_ENV
      else
        echo "SLACK_COLOR=danger" >> $GITHUB_ENV
        echo "SLACK_MESSAGE=This build has failed." >> $GITHUB_ENV
      fi

  - name: Send Build Notification
    uses: rtCamp/action-slack-notify@v2.1.0

[bagel-dawg]

Thanks! I’ll try out both solutions and select one.

[ansiwen]

I would recommend fromJSON('{"false": "danger", "true": "good"}')[job.status == 'success'] because it is more explicit and is a clean solution. With this pattern you can also do more sophisticated mapping like fromJSON('{"Linux":"so","macOS":"dylib","Windows":"dll"}')[runner.os].

[ansiwen]

For anybody who's trying to use this to set an env var, the runner context is not available for env.

Why would you think that? I'm using it to set an env variable: https://github.com/Nitrokey/nethsm-pkcs11/blob/b43302dfc0352a07f86de2869c35bdd12b4d1944/.github/workflows/go.yml#L28

[m4heshd]

Why would you think that? I'm using it to set an env variable: https://github.com/Nitrokey/nethsm-pkcs11/blob/b43302dfc0352a07f86de2869c35bdd12b4d1944/.github/workflows/go.yml#L28

I'm not sure what kind of magic you're using there but here's the documentation. Check env. Only github, secrets, inputs contexts are available for env. So it working just for you is pretty magical.

Here's the error I ended up with, when I tried to use runner context.

Yes, I tried to use it exactly how you're utilizing it, in a job. Then I changed it to inputs (because I actually have inputs on my workflow) and it immediately worked. Didn't change anything else.

One difference I'm seeing in your case is the matrix strategy. But I don't need that if I'm using a matrix. I can simply use include which I use all the time. BTW you can too. Yes, it's not a one liner but pretty straight forward and provides much better readability.

Simply do:

  build:
    name: Build on ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macOS-latest]
        include:
          - os: ubuntu-latest
            lib_suffix: so
          - os: windows-latest
            lib_suffix: dll
          - os: macOS-latest
            lib_suffix: dylib
    steps:
    - uses: actions/checkout@v2

    - name: Set up Go
      uses: actions/setup-go@v2
      with:
        go-version: 1.17

    - name: Build
      run: go build -o out/p11nethsm.${{ matrix.lib_suffix }} -buildmode=c-shared -ldflags=-w -v

Or this:

include:
  - {os: ubuntu-latest, lib_suffix: so}
  - {os: windows-latest, lib_suffix: dll}
  - {os: macOS-latest, lib_suffix: dylib}

[m4heshd]

UPDATE:

Ok I just realized, runner is available for jobs.<job_id>.steps.env which you're utilizing. It's just not available for job's top level env. That's pretty odd since the runner is already initialized prior to starting a job. Oh well.. 🤷🏼

[ansiwen]

Oh, I see. No, that cannot work, because the runner is part of the job context. Actually it's even itself an environment variable of the job context, so that would be a recursion: Detecting the operating system

[m4heshd]

I know, that's why I said "That's pretty odd". It's not like a new runner is spawned for each step. It feels like it should clearly be available for job's env. That can be the last task executed just before running the first step. It makes perfect sense since that env is not available for any other top level key. Just for the steps and jobs that needs this particular job. It's just like setting an output on the very first step.