git-local-backup

A solution to automatically backup git repos on local / cloud-synced folders (Nextcloud, Dropbox, Google Cloud, etc.)

How to enable backup in a git repository

1. Clone git-local-backup repository:

   $ git clone https://github.com/dcommisso/git-local-backup.git
   

2. Link (or copy) hooks/post-commit to the repo to backup:

   $ ln -s git-local-backup/hooks/post-commit <YOUR-REPO>/.git/hooks/post-commit
   

3. Enter your repo and configure the directory where the backups will be saved:

   $ cd <YOUR-REPO>
   
   $ git config set gitlocalbackup.directory <BACKUP-DIRECTORY>
   

4. (Optional) Set the number of bundle files to keep:

   $ git config set gitlocalbackup.backupstokeep <NUMBER-OF-BACKUPS>
   

   Since a git bundle already contains all the repo's history, there's really no need to keep a lot of bundles, a value of 1 or 2 should be fine.

Configuring backup for new repositories

It's also possible to use git-local-backup repo as template for new repository, in order to create and install backup using just one command:

$ git init --template=git-local-backup <NEW-REPOSITORY>

Restore backup

Just run git clone on bundle file:

$ git clone <BACKUP-DIR>/<REPO-NAME>.bundle

Uninstall git-local-backup

Just delete the post-commit script in your repository:

$ rm <YOUR-REPO>/.git/hooks/post-commit

Rationale

I find it very convenient to use git for single user personal projects (not only programming but also for other stuff, e.g. literature projects or miscellaneous documentation). I don't need synchronization with other users but I still need a backup. Since it's private stuff I don't want to use public git servers, but at the same time I also don't want the hassle of maintaining (and backupping) a private git server or to encrypt them. The ideals solution for me is using local directories synchronized with private cloud, but syncing a git repo in this way would most likely break it. So I ended up writing a bash script configured as post-commit git hook that runs git bundle after each commit, plus some logic to avoid cluttering backup folder with a lot of useless backups.

How it works

Since the script is configured as post-commit git hook, it will be automatically executed after each commit. The script runs git bundle create --all and saves the bundle in backup directory defined in gitlocalbackup.directory, creates/moves the link to the last backup file and deletes older bundles (if configured) according to gitlocalbackup.backupstokeep git option. Please check the console logs after each commit to make sure the backup worked properly.

Sync a repository between devices

If the directory where the backup is stored is accessible by other devices it's possible to keep repositories in sync:

$ git clone <BACKUP-DIR>/<REPO-NAME>.bundle

... the repository is updated and backupped from a different device

$ git pull

however this is dangerous and shouldn't be abused: if the shared directory is not promptly updated there is a risk of losing data. If a robust sync is needed, it's better to rely on a git server.