"Think globally,
act
locally"
Run your GitHub Actions locally! Why would you want to do this? Two reasons:
- Fast Feedback - Rather than having to commit/push every time you want to test out the changes you are making to your
.github/workflows/
files (or for any changes to embedded GitHub actions), you can useact
to run the actions locally. The environment variables and filesystem are all configured to match what GitHub provides. - Local Task Runner - I love make. However, I also hate repeating myself. With
act
, you can use the GitHub Actions defined in your.github/workflows/
to replace yourMakefile
!
How Does It Work?
When you run act
it reads in your GitHub Actions from .github/workflows/
and determines the set of actions that need to be run. It uses the Docker API to either pull or build the necessary images, as defined in your workflow files and finally determines the execution path based on the dependencies that were defined. Once it has the execution path, it then uses the Docker API to run containers for each action based on the images prepared earlier. The environment variables and filesystem are all configured to match what GitHub provides.
Let's see it in action with a sample repo!
Installation
To install with Homebrew, run:
brew install nektos/tap/act
Alternatively, you can use the following:
curl https://raw.githubusercontent.com/nektos/act/master/install.sh | sudo bash
If you are running Windows, download the latest release and add the binary into your PATH.
If you are using Chocolatey then run:
choco install act-cli
If you are using Scoop then run:
scoop install act
If you are running Arch Linux, you can install the act package with your favorite package manager:
yay -S act
If you are using NixOS or the Nix package manager on another platform you can install act globally by running
nix-env -iA nixpkgs.act
or in a shell by running
nix-shell -p act
Commands
# List the actions
act -l
# Run the default (`push`) event:
act
# Run a specific event:
act pull_request
# Run a specific job:
act -j test
# Run in dry-run mode:
act -n
# Enable verbose-logging (can be used with any of the above commands)
act -v
Flags
-b, --bind bind working directory to container, rather than copy
-C, --directory string working directory (default ".")
-n, --dryrun dryrun mode
--env-file string environment file to read (default ".env")
-e, --eventpath string path to event JSON file
-h, --help help for act
-j, --job string run job
-l, --list list workflows
-P, --platform stringArray custom image to use per platform (e.g. -P ubuntu-18.04=nektos/act-environments-ubuntu:18.04)
-p, --pull pull docker image(s) if already present
-q, --quiet disable logging of output from steps
-r, --reuse reuse action containers to maintain state
-s, --secret stringArray secret to make available to actions with optional value (e.g. -s mysecret=foo or -s mysecret)
--secret-file file with list of secrets to read from (e.g. --secret-file .secrets)
-v, --verbose verbose output
--version version for act
-w, --watch watch the contents of the local repo and run when files change
-W, --workflows string path to workflow files (default "./.github/workflows/")
Known Issues
MODULE_NOT_FOUND during docker cp
command #228
steps:
- name: Checkout
uses: actions/checkout@v2
with:
path: "your-action-root-directory"
Runners
GitHub Actions offers managed virtual environments for running workflows. In order for act
to run your workflows locally, it must run a container for the runner defined in your workflow file. Here are the images that act
uses for each runner type:
GitHub Runner | Docker Image |
---|---|
ubuntu-latest | node:12.6-buster-slim |
ubuntu-18.04 | node:12.6-buster-slim |
ubuntu-16.04 | node:12.6-stretch-slim |
windows-latest | unsupported |
windows-2019 | unsupported |
macos-latest | unsupported |
macos-10.15 | unsupported |
Default runners are intentionally incomplete
These default images do not contain all the tools that GitHub Actions offers by default in their runners.
Alternative runner images
If you need an environment that works just like the corresponding GitHub runner then consider using an image provided by nektos/act-environments:
- nektos/act-environments-ubuntu:18.04 - built from the Packer file GitHub uses in actions/virtual-environments.
*** WARNING - this image is >18GB 😱***
Use an alternative runner image
To use a different image for the runner, use the -P
option:
act -P ubuntu-latest=nektos/act-environments-ubuntu:18.04
Secrets
To run act
with secrets, you can enter them interactively or supply them as environment variables. The following options are available for providing secrets:
act -s MY_SECRET=somevalue
- usesomevalue
as the value forMY_SECRET
.act -s MY_SECRET
- check for an environment variable namedMY_SECRET
and use it if it exists. If the environment variable is not defined, prompt the user for a value.
Configuration
You can provide default configuration flags to act
by either creating a ./.actrc
or a ~/.actrc
file. Any flags in the files will be applied before any flags provided directly on the command line. For example, a file like below will always use the nektos/act-environments-ubuntu:18.04
image for the ubuntu-latest
runner:
# sample .actrc file
-P ubuntu-latest=nektos/act-environments-ubuntu:18.04
Additionally, act supports loading environment variables from an .env
file. The default is to look in the working directory for the file but can be overridden by:
act --env-file my.env
Events
Every GitHub event is accompanied by a payload. You can provide these events in JSON format with the --eventpath
to simulate specific GitHub events kicking off an action. For example:
{
"pull_request": {
"head": {
"ref": "sample-head-ref"
},
"base": {
"ref": "sample-base-ref"
}
}
}
act -e pull-request.json
Act will properly provide github.head_ref
and github.base_ref
to the action as expected.
Support
Need help? Ask on Gitter!
Contributing
Want to contribute to act? Awesome! Check out the contributing guidelines to get involved.
Building from source
- Install Go tools 1.11.4+ - (https://golang.org/doc/install)
- Clone this repo
git clone git@github.com:nektos/act.git
- Pull the default docker image
docker pull nektos/act-environments-ubuntu:18.04
- Run unit tests with
make test
- Build and install:
make install