How I handle multiple Git configurations

I do work on multiple repositories all the time, be it for personal stuff like my Neovim configuration, this webpage, or for my clients. That means that I need to manage different user.name and user.email settings for my Git configuration (in addition to SSH keys).

Direnv

#

For years, I used direnv to solve this problem of multiple Git configurations.

direnv is an extension for your shell. It augments existing shells with a new feature that can load and unload environment variables depending on the current directory.

Direnv lets you define certain aspects of your shell, e.g. exported variables, on a per directory basis. Direnv “hooks” into your zsh (or bash) and whenever you cd into a directory containing a .envrc file it gets sourced. Direnv also looks for .envrc in the parent directories allowing you to define one .envrc file for a whole bunch of subdirectories, e.g. for a certain client or project.

The second part of my old approach is a bash script to set global Git settings:

case $param in
    client1 )
        notify "Generating client1 config"
        git config --global user.email "michael.peter@client1.de"
        git config --global user.name "Michael Peter"
        git config --global credential.username "michael.peter"
        ;;
    github )
        notify "Generating github config"
        git config --global user.email "michaeljohannpeter@gmail.com"
        git config --global user.name "Michael"
        git config --global credential.username "allaman"
        ;;
esac

Combining those results in a .envrc file containing the call to the script and the appropriate parameter like so

~/.local/bin/gitconfig.sh github

Those .envrc files are place in the root folder of my projects (with the appropriate argument):

kunden
└── client1
    ├── project1
    ├── project2
    └── .envrc
└── client2
    ├── project1
    ├── project2
    └── .envrc
workspace
└── github
    ├── project1
    ├── project2
    └── .envrc
└── gitea
    ├── project1
    ├── project2
    └── .envrc

Every time I cd into a project the .envrc of the root directory is read and my global Git configuration is updated.

There are two major disadvantages of this approach:

1. It is “slow”. Each time I cd into a project folder the script is called by Direnv. Even when my Git credentials are already correct. I could implement a check in the bash script but the check alone would probably be more logic than the configuration logic itself. I don’t know why executing such a small script via Direnv takes a notable time but maybe because of the little misuse ;). I use Direnv farther for setting project specific ENV variables.
2. It is not as “safe” as I would like it to be. As I said when ever I cd into a directory my Git configuration is altered. Imagine I work for client1 in one Tmux window and suddenly must switch to client2 in another Tmux window. When switching back to client1 and its Tmux window my Git is configured to client2 because I did not cd into a client1 project! So I always have to be somehow aware of my contexts and of course I forgot it from time to time resulting in a wrong commit author.

IncludeIf

#

Due to those disadvantages I was thinking about a new approach how to handle my various Git configurations. I came across the IncludeIf directive which looks like it exists for some years now facepalm. This allows me to configure my user.name and user.email setting (and more) in a separate file per client and reference it in my global ~/.gitconfig. Refer to the previously linked documentation for more filter options.

cat ~/.gitconfig

[includeIf "gitdir:~/kunden/client1/"]
  path = ~/.gitconfig-client1
[includeIf "gitdir:~/workspace/github.com/"]
  path = ~/.gitconfig-gh

cat .secrets/gitconfig-gh-allaman

[user]
	email = michaeljohannpeter@gmail.com
	name = Michael

The benefits over this approach are as follows:

1. No shell manipulation or scripting is involved
2. No need to cd into a folder to activate the correct settings (or do so manually)

SSH keys

#

To be able to authenticate I specify the SSH key for each repository in my ~/.ssh/config e.g.

Host github.com
 HostName github.com
 User git
 AddKeysToAgent yes
 IdentityFile ~/.ssh/id_rsa