Create a Git Hook to pull data on another folder every time I push in the remote repository

Question

I'm currently creating a Github repository for a better structure of my project. I want my project to be viewed by other peoples via link-only (because they don't have github), but I don't have found a solution. So I'm trying to transfer my project files in OneDrive and I have succeeded : I have git init my folder in OneDrive and I have git pull my github repository. This OneDrive folder will only receive new files, I'm updating my project with an other folder in my computer. Now, I want this procedure to be automatic every time I git push my updates to my remote repository. I've tried to create that code (but I'm not sure if he's ok) :

cd "D:/Ewan/OneDrive/MyFolder" // Once I git push, I go to the folder to update it
git pull <github-repo> <my-branch>

I want to implement it into a git hook file, but I've now idea in which and where in the code already written...

Can you help me please ? Thanks !

PS : some hooks like post-receive are not in my .git folder.

Answer 1

First, let me note that combining two different "tracking systems" (Git and OneDrive here) for the same folder is error-prone and can lead to inconsistencies (for instance).

So, I'd suggest you work in one Git repository stored outside of the OneDrive folder; this repository can be synchronized with GitHub or other remotes anytime you want, and it is then possible to ensure that every time you pull or merge something in your local master branch, a Git hook also reliably copies the branch contents to your OneDrive folder, which can then be synchronized automatically.

Regarding hooks, note that this use case can be viewed as a somewhat non-standard one, given "auto-deploy hooks" are typically used in server-side bare repositories, using a post-receive hook that is triggered after receiving a Push. However, it appears that from local side as well (in a non-bare repository), the post-merge hook may provide a solution to address this specific use case!

In the sequel, I assume your repository is stored in $HOME/git/project and you want to auto-deploy its contents in $HOME/OneDrive/MyFolder every time you do a git pull or any git merge in the master branch (namely, git pull in feature branches won't make the hook to run).

A comprehensive proof-of-concept of this idea

#!/usr/bin/env bash
# PoC(post-merge); see https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks

# Assuming the ambient Git repo is NOT a bare repo (i.e., it has a working dir)

# Get unambiguous branch name; see https://stackoverflow.com/a/61808046/9164010
current_branch=$(git rev-parse --symbolic-full-name HEAD)
target_branch="refs/heads/master"

# TODO: Update this variable accordingly (a trailing slash is optional here):
dest_dir="$HOME/OneDrive/MyFolder"

# Redirect output to stderr
exec 1>&2

if [ "$current_branch" != "$target_branch" ]; then
    echo "post-merge: no-op (NOT on $target_branch)"
else
    echo "post-merge: on $target_branch (in $PWD)"

    # Use mktemp + git-archive to avoid issues with a "dirty working directory"
    # as well as with files to be ignored (e.g., the .git subdirectory itself);
    # this is just ONE possible approach (which resets timestamps in $dest_dir)
    # and other ones might be considered (e.g., using "rsync --exclude-from" …)
    temp_dir=$(mktemp -d) || { echo "Failed to create tmp directory"; exit 2; }
    set -exo pipefail
    git archive --format=tar HEAD -- . | ( cd "$temp_dir/" && tar xf -)
    rsync -a --delete-delay "$temp_dir/" "$dest_dir"
    # Note that in the param $temp_dir/ above, the trailing slash is mandatory.
    rm -fr "$temp_dir"
fi

Installation instructions

You'll just need to run:

touch ~/git/project/.git/hooks/post-merge
chmod a+x ~/git/project/.git/hooks/post-merge

# then edit this file with any text editor of your choice, pasting the code above
gedit ~/git/project/.git/hooks/post-merge &

Disclaimer: this Git hook relies on bash and rsync (which you may need to install beforehand); and I only tested it on GNU/Linux…

As an aside, if you need to extend or refactor this suggested shell code, I would recommend to always run the shellcheck linter on your script before using it in production.