Question

How to use outputs from a reusable workflow in github?

Answer 1

A reusable workflow may generate data that you want to use in the caller workflow. To use these outputs, you must specify them as the outputs of the reusable workflow.

If a reusable workflow that sets an output is executed with a matrix strategy, the output will be the output set by the last successful completing reusable workflow of the matrix which actually sets a value. That means if the last successful completing reusable workflow sets an empty string for its output, and the second last successful completing reusable workflow sets an actual value for its output, the output will contain the value of the second last completing reusable workflow.

The following reusable workflow has a single job containing two steps. In each of these steps we set a single word as the output: "hello" and "world." In the outputs section of the job, we map these step outputs to job outputs called: output1 and output2. In the on.workflow_call.outputs section we then define two outputs for the workflow itself, one called firstword which we map to output1, and one called secondword which we map to output2.

YAML

name: Reusable workflow

on:
  workflow_call:
    # Map the workflow outputs to job outputs
    outputs:
      firstword:
        description: "The first output string"
        value: ${{ jobs.example_job.outputs.output1 }}
      secondword:
        description: "The second output string"
        value: ${{ jobs.example_job.outputs.output2 }}

jobs:
  example_job:
    name: Generate output
    runs-on: ubuntu-latest
    # Map the job outputs to step outputs
    outputs:
      output1: ${{ steps.step1.outputs.firstword }}
      output2: ${{ steps.step2.outputs.secondword }}
    steps:
      - id: step1
        run: echo "firstword=hello" >> $GITHUB_OUTPUT
      - id: step2
        run: echo "secondword=world" >> $GITHUB_OUTPUT

We can now use the outputs in the caller workflow, in the same way you would use the outputs from a job within the same workflow. We reference the outputs using the names defined at the workflow level in the reusable workflow: firstword and secondword. In this workflow, job1 calls the reusable workflow and job2 prints the outputs from the reusable workflow ("hello world") to standard output in the workflow log.

YAML

name: Call a reusable workflow and use its outputs

on:
  workflow_dispatch:

jobs:
  job1:
    uses: octo-org/example-repo/.github/workflows/called-workflow.yml@v1

  job2:
    runs-on: ubuntu-latest
    needs: job1
    steps:
      - run: echo ${{ needs.job1.outputs.firstword }} ${{ needs.job1.outputs.secondword }}