Communication, Outputs, and Environments

Outputs and Job Communication

Consolidated from GitHub_Actions_Outputs_and_Job_Communication.md with practical examples and patterns for step outputs, job outputs, artifacts.

Preserved content excerpts (from `GitHub_Actions_Outputs_and_Job_Communication.md`)

Step outputs (`$GITHUB_OUTPUT`)

Use step outputs to pass small pieces of data (strings) to later steps in the same job.

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - id: version
        run: echo "VERSION=1.2.3" >> "$GITHUB_OUTPUT"

      - name: Use version
        run: echo "Version is $VERSION"
        env:
          VERSION: ${{ steps.version.outputs.VERSION }}

Job outputs (`jobs.<job>.outputs`)

Use job outputs to pass data between jobs (requires needs: so the producer runs first).

jobs:
  job1:
    runs-on: ubuntu-latest
    outputs:
      release_url: ${{ steps.create.outputs.url }}
    steps:
      - id: create
        run: echo "url=https://example.com/release/123" >> "$GITHUB_OUTPUT"

  job2:
    runs-on: ubuntu-latest
    needs: job1
    steps:
      - run: echo "Release URL is ${{ needs.job1.outputs.release_url }}"

Artifacts (files between jobs)

If you need to share files (not small strings), upload/download artifacts between jobs.

Environments and Environment Variables

Consolidated from Environments_and_Variables.md covering scopes, contexts, GITHUB_ENV, GITHUB_OUTPUT, best practices, and troubleshooting.

Preserved content excerpts (from `Environments_and_Variables.md`)

Each step runs in its own process.
Steps in the same job share the same workspace on disk (filesystem changes persist).
Shell variables set inside a step do not automatically persist to the next step.

Persisting env vars across steps (`$GITHUB_ENV`)

steps:
  - name: Set env var for later steps
    run: echo "FOO=bar" >> "$GITHUB_ENV"

  - name: Read env var
    run: echo "$FOO"

Important caveat: secrets in `if:`

GitHub does not allow ${{ secrets.X }} directly in if:. If you need conditional logic, pass the secret to an env: var and test that.

Webhooks and External Notifications

Consolidated from Webhooks.md: ChatOps concepts, repository_dispatch, Teams/Slack/Discord examples, security considerations, and sample workflows.

Preserved content excerpts (from `Webhooks.md`)

Webhooks let external systems trigger workflows. This enables ChatOps-style controls (e.g., “deploy” from Slack/Teams/Discord).
For GitHub Actions, use repository_dispatch for externally-triggered workflows.

on:
  repository_dispatch:
    types: [deploy-production]

Security notes

Treat webhook triggers as production-impacting: require authentication and authorization.
Store webhook URLs/tokens in GitHub Secrets, and limit who can trigger dispatch events.