Github Actions Notes

README.md

• Context variables - availability varies based on workflow step

  • github e.g. ${{ github.actor }}
  • env
  • vars
  • job, jobs
  • steps
  • runner
  • secrets
  • strategy
  • matrix
  • needs
  • inputs

• Triggers

  • Events
  • Manual
  • Filters
  • Schedule ...

• Define Actions used in workflow

  • Same repo as the workflow file e.g. {owner}/{repo}@{ref} or ./path/to/dir syntax
  • Any public repo e.g. {owner}/{repo}@{ref}
  • Docker Image e.g. docker://{image}:{tag}
  • Refs can be - tags, SHAs, branches

• Inputs & Outputs

• Environment variables using env:

• Scripts using run: - command or script location e.g. ./.github/scripts/build.sh

• Conditions

  • if e.g. if: ${{ <expression> }}

• Functions

  • contains( search, item ), contains(github.event.issue.labels.*.name, 'bug'), contains(fromJSON('["push", "pull_request"]'), github.event_name)
  • startsWith( searchString, searchValue )
  • endsWith( searchString, searchValue )
  • format( string, replaceValue0, replaceValue1, ..., replaceValueN)
  • join( array, optionalSeparator )
  • toJSON(value)
  • fromJSON(value)
  • Status checks
    • if: ${{ success() }}
    • if: ${{ cancelled() }}
    • if: ${{ failure() }}

• Pass Values

  • Job to Job - use job output
  • Between steps in a Job - use env var & GITHUB_ENV file

• Job dependency - needs

• Cache dependencies

• Workflow commands

  • echo "::debug::Set the Octocat variable"
  • group log lines ::group::{title}::endgroup::

• Starter Workflows

• Reusing Workflows

  • Called Workflow workflow_call:, inputs, secrets
  • Caller Workflow uses, with

• Cache dependencies

• Jobs

  • Run on containers

• Service Containers