Git config with multiple identities and multiple repositories

multiple-repository-and-identities-git-configuration.md

Setup multiple git identities & git user informations

/!\ Be very carrefull in your setup : any misconfiguration make all the git config to fail silently ! Go trought this guide step by step and it should be fine 😉

Setup multiple git ssh identities for git

• Generate your SSH keys as per your git provider documentation.

• Add each public SSH keys to your git providers acounts.

• In your ~/.ssh/config, set each ssh key for each repository as in this exemple:

    Host github.com
    	HostName github.com
    	User git
    	IdentityFile ~/.ssh/github_private_key
    	IdentitiesOnly=yes
    Host gitlab.com
    	Hostname gitlab.com
    	User git
    	IdentityFile ~/.ssh/gitlab_private_key
    	IdentitiesOnly=yes

Setup dynamic git user email & name depending on folder

/!\ Require git 2.13+ for conditional include support.

The idea here is to use a different git user name & email depending on the folder you are in.

• In your ~/.gitconfig, remove the [user] block and add the following (adapt this exemple to your needs) :

    [includeIf "gitdir:~/code/personal/"]
    	path = .gitconfig-personal
    [includeIf "gitdir:~/code/professional/"]
    	path = .gitconfig-professional

• In your ~/.gitconfig-personal, add your personnal user informations:

    [user]
    	email = [email protected]     # note we use the noreply github mail
    	name = personal_username

• In your ~/.gitconfig-professional, add your professional user informations:

    [user]
    	email = [email protected]
    	name = professional_username

Setup a GPG key

If you need to add a GPG key and bind it to a user to sign your commits, you can do so like this:

You should have GPG installed and configured like the GPG suite

• Add the GPG key ID to your ~/.gitconfig-<PROFILE> config and enable commit signing:

  [user]
    email = [email protected]
    name = Your NAME
    signingkey = SIGNING_KEY_ID
  [commit]
    gpgsign = true

• Make sure to register the right GPG binary in your ~/.gitconfig:

  [program]
    pgp = /path/to/your/gpg2/bin

Test your setup

• Now each repository will use the custom user info setup depending on the top-level folder.

• Check your settings are taken into account, for instance in ~/code/personal/ :

  $ cd ~/code/personal/
  $ git config --get user.email    	# should return [email protected] as per the exemple
  $ git config --get user.name     	# should return personal_username as per the exemple
  $ git config --get user.signingkey	# should return the GPG key ID as configured for the user

• Do the same for each folder you have setup.

• You can also display and check the global git config: git config --list --global

  • Or just the local config for the repository folder you are in: git config --list

• Done !

Roadmap

• use git config commands instead of config file manual editions (editing config directly is kind of dangerous but is more understandable, maybe keep it like this ?)

I originally had a problem with using two hosts and when I signed my commits, the signature would be invalid on the web UI because my global git email was set to github only. What I wanted to do was figure out a way to automatically change the user.email variable to the respective noreply addresses.

That can be done using the IncludeIf directive, just have to use the right globbing pattern.
My config is like this :

[includeIf "hasconfig:remote.*.url:**github.com:*/*.git"]
	path = github_config 

[includeIf "hasconfig:remote.*.url:**codeberg.org:*/*.git"]
	path = codeberg_config

Where github_config and codeberg_config are files with their respective emails. The globbing pattern is just :

**example.com:*/*.git

for ssh remote urls.

@shellheim nice tip 👍