Using git clean in a deployment hook

A typical post-receive hook for updating a target directory based on the most recent commit might look like this:


export GIT_WORK_TREE="../myproject"
git checkout -f master

However, this does not remove any untracked files or directories in ../myproject. When files are removed or renamed in later commits, their remnants will remain untouched in the deployment directory. How can we get rid of them?

Enter git clean! Remove all untracked files and directories like so.

git clean -fd
# -f forces removal of files without prompting
#    or disabling config variable `clean.requireForce`
# -d recurses into untracked directories

But what about all of those extra runtime files like databases and logs—how do we avoid deleting them? The strategy taken here is to add these files to .gitignore. git clean ignores these files by default.

The other tricky point is that git checkout should be run before git clean in order to ensure an up-to-date .gitignore. Otherwise, runtime files we later remember to add to .gitignore may be deleted before .gitignore gets updated.

Here’s what the final hook looks like:


# Enable immediate exit on error
set -e

# Set git directories
export GIT_WORK_TREE="../myproject"

# Checkout all files in the target directory to match the repository
# Must update .gitignore before running `git clean`
git -c advice.detachedHead=false checkout -f refs/heads/master

# Clean untracked files and directories in the target directory
# Do not remove files which are listed within .gitignore
git clean -fd