Get the duration of a GitHub Actions workflow run (in the workflow)

RajanM12

In GitHub Actions, in a post-build step I need to get the total build duration (or run duration up to that point) in order to output to log / Slack etc.

As far as I can see the GitHub API doesn't provide access to this, but seems like such a basic thing... is there really not a way to directly access??

robbie

Ah I've hit this before myself. Does seem mad they're still not giving access to this in the workflow run.

Obviously it's straight-forward to track it yourself (though annoying you have to):

Set a timestamp right at the start of the run, here I'm passing it to an output parameter called startTimestamp

      - name: Set start timestamp
        id: start-timestamp
        run: |
          printf 'startTimestamp=%(%s)T\n' >> "$GITHUB_OUTPUT"

Post-build, calculate the duration comparing the current time to start time. Can then use this in any following steps, whether sending to a log, Slack, etc!
Note in this example I'm assuming the workflow is broken into separate jobs - an initial "pre-build" job, and then the latter in a "post-build" job

      - name: Calculate build duration
        id: calculate-duration
        run: |
          printf -v now '%(%s)T'
          echo buildDuration=$((now - ${{ needs.pre-build.outputs.startTimestamp }})) >> "$GITHUB_OUTPUT"