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 = user.personal@users.noreply.github.com     # note we use the noreply github mail
    	name = personal_username

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

    [user]
    	email = user.professional@dns.com
    	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 = your.mail@domain.com
    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 user.personal@users.noreply.github.com 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 ?)