Learn GitHub Actions #494

Workflow file for this run

.github/workflows/cheat-sheet.yml at 6605c18

	# This is a GitHub Actions workflow file
	# Workflows are defined in YAML files in your repository's .github/workflows/ directory
	# Comments in YAML look like this.

	# Name of the workflow (displayed in the Actions tab)
	name: Learn GitHub Actions

	# Optional: The name for workflow runs generated from the workflow.
	run-name: Learning GitHub Actions workflow triggered by ${{ github.actor }}

	# Events that trigger the workflow
	on:
	# Trigger on push
	push:
	# Path filters
	paths:
	- "src/**" # Any file in src/ and subdirectories
	- "docs/*.md" # Markdown files in docs/ only
	- "**.js" # JavaScript files anywhere
	- "!src/test/**" # Exclude test files
	- "config/[a-z]*.yml" # YAML files starting with lowercase letter
	- ".github/workflows/**" # Any workflow file changes

	# Branch filters
	branches:
	- main # main branch
	- "release/v[0-9].[0-9]" # release/v1.0, release/v2.1, etc.
	- "feature/*" # Any feature branch
	- "!experimental" # Exclude experimental branch

	# Tag filters
	tags:
	- "v[0-9]+.[0-9]+.[0-9]+" # Semantic version tags
	- "!*-alpha" # Exclude alpha tags

	# Trigger on pull requests targeting main
	pull_request:
	branches: [main]

	# Trigger on pull request reviews
	pull_request_review:
	types: [submitted]

	# Trigger manually from the GitHub UI
	workflow_dispatch:
	# Optional: Define inputs for manual trigger
	inputs:
	example-input:
	description: "An example input for manual trigger"
	required: false # Whether this input is required
	default: "default-value"
	type: string # type can be string, boolean, choice, environment, or number

	# Trigger on a schedule (cron syntax)
	schedule:
	- cron: "0 0 * * *" # Daily at midnight UTC

	# Environment variables available to all jobs
	env:
	NODE_VERSION: 24
	PYTHON_VERSION: "3.9"

	# Use permissions to modify the default permissions granted to the GITHUB_TOKEN
	# Start read-only at the top level and grant writes per job that needs them.
	permissions:
	read-all # write-all\|read-all or disable with {}
	# actions: read\|write\|none
	# attestations: read\|write\|none
	# checks: read\|write\|none
	# contents: read\|write\|none
	# deployments: read\|write\|none
	# id-token: write\|none
	# issues: read\|write\|none
	# models: read\|none
	# discussions: read\|write\|none
	# packages: read\|write\|none
	# pages: read\|write\|none
	# pull-requests: read\|write\|none
	# security-events: read\|write\|none
	# statuses: read\|write\|none

	# Provide defaults for steps
	defaults:
	run:
	shell: bash # Default shell for all run steps
	working-directory: ./ # Default working directory for all run steps

	# Concurrency allows you to control the concurrency of workflow runs.
	concurrency:
	# The concurrency key is used to group workflows or jobs together into a concurrency group.
	group: ci-${{ github.ref }}
	# Cancel any in-progress job or run
	cancel-in-progress: true

	# Jobs are the core building blocks of workflows
	# All jobs run in parallel by default, each job is a new clean runner environment
	jobs:
	# Job ID (can be referenced by other jobs)
	basic-job:
	# Human-readable name for the job
	name: Basic Job Example

	# The type of runner to use
	runs-on: ubuntu-latest
	timeout-minutes: 10 # Maximum time this job can run before being cancelled

	permissions: # Permissions for the GITHUB_TOKEN in this job
	contents: read # Read access to repository contents
	issues: write # Write access to issues

	# Job level environment variables
	env:
	JOB_ENV: "development"

	# Conditionally run this job
	if: 1 == 1

	# Outputs from this job can be used by other jobs
	outputs:
	example-output: "Hello, World!"

	# List of steps to execute
	steps:
	# GitHub Actions are called with the uses keyword
	- uses: sormuras/hello-world-java-action@v1 # {owner}/{repo}/{path}@{ref}
	name: My first step # Steps can have names for better readability
	timeout-minutes: 5 # The maximum time this step can run before being cancelled
	continue-on-error: true # Whether to continue running the workflow if this step fails
	with:
	# Inputs are parameters passed to the action
	who-to-greet: "Mona the Octocat"

	# Reference a specific commit
	- uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
	# Reference the major version of a release
	- uses: actions/checkout@v7
	# Reference a specific version
	- uses: actions/checkout@v7.0.1
	# Reference a branch
	- uses: actions/checkout@main

	# Run a simple shell command
	- run: echo "Hello, GitHub Actions!"

	# Run multiple commands with literal data types
	- name: Demonstrate data types and basic commands
	run: \|
	echo "Current directory: $(pwd)"
	echo "Files: $(ls -la)"
	echo "Node version: $NODE_VERSION" # print job level environment variable
	echo "GitHub Token: ${{ secrets.GITHUB_TOKEN }}" # Secrets are automatically masked in logs
	echo "Value: $myIntegerNumber" # print step level environment variable
	echo "step-output=Hello, World!" >> $GITHUB_OUTPUT # Set step output
	echo "::group::Examples"
	echo "::add-mask::This is secret and masked"
	echo "::debug::This is a debug message"
	echo "::notice file=app.js,line=1,col=5,endColumn=7::Missing semicolon"
	stopMarker=$(uuidgen)
	echo "::stop-commands::$stopMarker"
	echo '::error:: This will NOT be rendered as a error, because stop-commands has been invoked.'
	echo "::$stopMarker::"
	echo '::warning:: This is a warning again, because stop-commands has been turned off.'
	echo "::endgroup::"
	echo "### Hello world! :rocket:" >> $GITHUB_STEP_SUMMARY # Create a job summary
	echo "Contains: ${{ contains('hello world', 'hello') }}"
	echo "Starts with: ${{ startsWith('hello world', 'hello') }}"
	echo "Ends with: ${{ endsWith('hello world', 'world') }}"
	echo "Format: ${{ format('Hello {0}!', 'world') }}"
	echo "Join: ${{ join(fromJSON('["apple", "banana", "cherry"]'), ', ') }}"
	echo "Object to JSON: ${{ toJSON(fromJSON('{"name": "octocat", "type": "mascot"}')) }}"
	echo "Hash Files: ${{ hashFiles('**/package-lock.json') }}"
	env:
	# Literal data types in expressions
	myNull: ${{ null }}
	myBoolean: ${{ false }}
	myIntegerNumber: ${{ 711 }}
	myFloatNumber: ${{ -9.2 }}
	myHexNumber: ${{ 0xff }}
	myExponentialNumber: ${{ -2.99e-2 }}
	myString: Mona the Octocat
	myStringInBraces: ${{ 'It''s open source!' }}
	# Secrets are automatically masked in logs
	GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	id: example-step
	working-directory: ./

	# Contexts are a way to access information about workflow runs
	- name: Dump GitHub context
	run: \|
	echo '${{ toJSON(github) }}'
	echo '${{ toJSON(env) }}'
	echo '${{ toJSON(vars) }}'
	echo '${{ toJSON(job) }}'
	echo '${{ toJSON(steps) }}'
	echo '${{ toJSON(runner) }}'
	echo '${{ toJSON(secrets) }}'
	echo '${{ toJSON(strategy) }}'
	echo '${{ toJSON(matrix) }}'
	echo '${{ toJSON(needs) }}'
	echo '${{ toJSON(inputs) }}'
	printenv

	# Use the outputs from a previous step
	- run: echo "${{ steps.example-step.outputs.step-output }}"

	# Step that continues on error
	- name: Step that might fail
	continue-on-error: true
	run: exit 1

	# Upload artifacts
	- name: Create artifact
	run: \|
	mkdir -p artifacts
	echo "Build artifact" > artifacts/output.txt
	echo "Build number: ${{ github.run_number }}" >> artifacts/output.txt

	- name: Upload artifact
	uses: actions/upload-artifact@v7
	with:
	name: build-artifacts
	path: artifacts/
	retention-days: 30

	# Conditionally run a step
	# The github context contains information about the workflow run and the event that triggered the run.
	- if: contains(fromJSON('["push", "pull_request"]'), github.event_name)
	run: echo "Deploying to production server on branch $GITHUB_REF"

	- if: ${{ always() }}
	run: echo "This step always runs"

	- if: ${{ cancelled() }}
	run: echo "This step runs if the workflow is cancelled"

	- if: ${{ failure() }}
	run: echo "This step runs if any previous step failed"

	# Object Filter Example
	- if: ${{ github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'bug') }}
	run: echo "This PR has a bug label"

	# Composite actions let your group multiple steps into a single yml file
	- name: Inline Composite Action
	uses: ./.github/actions/hello-world
	with:
	name: "GitHub Actions"
	greeting: "Hello"

	# Job with conditions and matrix strategy
	build-matrix:
	name: Build Matrix
	runs-on: ${{ matrix.os }}

	# Run this job only if the basic-job succeeds
	needs: basic-job

	# Run this job only on push events (not PRs)
	if: github.event_name == 'push'

	# Matrix strategy: run job multiple times with different configurations
	strategy:
	# Don't cancel other matrix jobs if one fails
	fail-fast: false
	# The maximum number of jobs to run in parallel
	max-parallel: 10
	matrix:
	os: [ubuntu-latest, windows-latest, macos-latest]
	node-version: [22, 24, 26]
	# Exclude specific combinations
	exclude:
	- os: windows-latest
	node-version: 26

	steps:
	- uses: actions/checkout@v7
	- name: Setup Node.js ${{ matrix.node-version }}
	uses: actions/setup-node@v7
	with:
	node-version: ${{ matrix.node-version }}
	cache: "npm"
	# Leverage caching to speed up builds
	- name: Cache node modules
	id: cache-npm
	uses: actions/cache@v6
	env:
	cache-name: cache-node-modules
	with:
	# npm cache files are stored in `~/.npm` on Linux/macOS
	path: ~/.npm
	key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
	restore-keys: \|
	${{ runner.os }}-build-${{ env.cache-name }}-
	${{ runner.os }}-build-
	${{ runner.os }}

	- if: ${{ steps.cache-npm.outputs.cache-hit != 'true' }}
	name: List the state of node modules
	continue-on-error: true
	run: npm list

	- run: npm i
	- run: npm run build
	- run: npm test

	container-job:
	runs-on: ubuntu-latest
	container:
	image: node:24
	env:
	NODE_ENV: development
	ports:
	- 80
	volumes:
	- my_docker_volume:/volume_mount
	options: --cpus 1
	steps:
	- name: Check for dockerenv file
	run: (ls /.dockerenv && echo Found dockerenv) \|\| (echo No dockerenv)

	# Job demonstrating services (databases, caches, etc.)
	services-job:
	name: Services Example
	runs-on: ubuntu-latest

	# Define service containers
	services:
	# PostgreSQL service
	postgres:
	image: postgres:13
	env:
	POSTGRES_PASSWORD: postgres
	POSTGRES_DB: testdb
	options: >-
	--health-cmd pg_isready
	--health-interval 10s
	--health-timeout 5s
	--health-retries 5
	ports:
	- 5432:5432

	# Redis service
	redis:
	image: redis:6
	options: >-
	--health-cmd "redis-cli ping"
	--health-interval 10s
	--health-timeout 5s
	--health-retries 5
	ports:
	- 6379:6379

	steps:
	- uses: actions/checkout@v7
	- name: Test database connection
	run: \|
	sudo apt-get update
	sudo apt-get install -y postgresql-client
	PGPASSWORD=postgres psql -h localhost -p 5432 -U postgres -d testdb -c '\l'
	- name: Test Redis connection
	run: \|
	sudo apt-get install -y redis-tools
	redis-cli -h localhost -p 6379 ping

	# Reusable workflows are reusable jobs
	reusable-job:
	uses: austenstone/actions-playground/.github/workflows/reusable-called.yml@main
	with:
	username: "GitHub Actions User"
	secrets: inherit # You must pass secrets explicitly to reusable workflows

	# Job for deployment (typically runs after tests pass)
	deploy:
	name: Deploy Application
	runs-on: ubuntu-latest

	# Only run on main branch and after other jobs succeed
	if: github.ref == 'refs/heads/main'
	needs: [basic-job, build-matrix]

	# Grant only what the commenting steps below actually need
	permissions:
	contents: read
	issues: write
	pull-requests: write

	# Use environments to track deployments and protect sensitive operations.
	# Deliberately a throwaway name: pointing a demo at a real environment
	# records fake deployments against it and trips its protection rules.
	environment:
	name: demo-production
	url: https://myapp.example.com

	steps:
	- uses: actions/checkout@v7

	# Download artifacts from previous jobs
	- name: Download artifacts
	uses: actions/download-artifact@v8
	with:
	name: build-artifacts
	path: ./artifacts
	- name: Deploy to production
	run: \|
	echo "Deploying to production..."
	echo "Artifact contents:"
	cat ./artifacts/output.txt

	# The GitHub CLI is pre-installed on GitHub-hosted runners
	- run: \|
	gh pr comment ${{ github.event.pull_request.number }} \
	--body "🚀 Deployment Successful!"
	if: github.event_name == 'pull_request' && success()
	# To use the GitHub CLI, you need to authenticate with a token
	env:
	GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

	# Basic GitHub Script example - create an issue comment
	- name: Comment on issue
	uses: actions/github-script@v9
	with:
	script: \|
	github.rest.issues.createComment({
	issue_number: context.issue.number,
	owner: context.repo.owner,
	repo: context.repo.repo,
	body: '👋 Comment from github-script!'
	})

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Learn GitHub Actions #494

Workflow file

Learn GitHub Actions #494

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Workflow file for this run