How to Use Git Hooks to Automate Your Workflows
What Is a Git Hook
Git hooks are scripts that help automate tasks before or after certain Git commands are executed. These events are generally used for pre-commit checks on the server side.
Git hooks can be used to:
- Check commits for errors before they are pushed.
- Ensure code meets project standards.
- Notify team members about changes.
- Push code into a production environment, and more.
Why You Should be Using Git Hooks for Automation
Although you can use git hooks for a variety of reasons, they are very effective if you have or are implementing Continuous Integration/ Continuous Delivery (CI/CD). It can help remove bottle necks in your workflow and keep teams productive.
For example, you can push changes to your staging area or a production environment without ever having to leave Git. This makes developers’ changes available immediately for testing.
How Do Git Hooks Work
Working with hooks is a matter of writing scripts in the .git/hooks subdirectory for a repository. This subdirectory is preloaded with example scripts to get your started.
Git hooks support both client-side and server-side automation.
Client-Side Git Hooks
Client-side hooks are available for pre-commit, pre-rebase, post-checkout, and post-merge, etc. They provide a fair amount of flexibility for workflows on a local machine. These are not copied with cloning a repository.
Adding hooks to client-side will not enforce a policy across your organization. To implement automation, you need to use a server-side hook.
Server-Side Git Hooks
Server-side hooks work like client hooks, but they are stored in the server repository. They run before or after changes are pushed to the server. If conditions are not met, these hooks can reject a push and send an error back to the client. Examples include:
- Pre-receive hooks that run when changes are pushed from a client.
- Update hooks that run once on each branch being updated prior to changes being accepted.
- Post-receive hooks that run after the push process is completed to notify other users.
Setting Up Git Hooks
By default you’ll find the following in the .git/hooks folder :
applypatch-msg.sample commit-msg.sample post-update.sample pre-applypatch.sample pre-commit.sample pre-push.sample pre-rebase.sample prepare-commit-msg.sample update.sample
These files provide examples of how to build hook scripts for the various types of tasks. Built-in scripts are mostly written in PERL, but you can use any scripting language (as long as it can be executed).
To set them up you need to:
- Copy an example to the same name.
- Delete the .sample extension.
- Edit it as needed.
The hook will execute the next time it’s triggered.
Git Hooks in Perforce
Perforce offers a Git solution that gives you visibility into all your repositories and hooks. Using Helix TeamHub, you can see what hooks apply to what repos. And you can filter your repository hooks to display by the type of service.
Because all your repos can be in one big project, you get a single source of truth that allows for faster builds.
Want to learn more? Explore Git best practices.