Is it possible to have different Git configuration for different projects?

As of git version 2.13, git supports conditional configuration includes. In this example we clone Company A's repos in ~/company_a directory, and Company B's repos in ~/company_b.

In your .gitconfig you can put something like this.

[includeIf "gitdir:~/company_a/"]
  path = .gitconfig-company_a
[includeIf "gitdir:~/company_b/"]
  path = .gitconfig-company_b

Example contents of .gitconfig-company_a (the core section can be omitted if the global ssh key can be used)

[user]
name = John Smith
email = [email protected]

[core]
sshCommand = ssh -i ~/.ssh/id_rsa_companya

Example contents of .gitconfig-company_b

[user]
name = John Smith
email = [email protected]

[core]
sshCommand = ssh -i ~/.ssh/id_rsa_companyb

There are 3 levels of git config; project, global and system.

• project: Project configs are only available for the current project and stored in .git/config in the project's directory.
• global: Global configs are available for all projects for the current user and stored in ~/.gitconfig.
• system: System configs are available for all the users/projects and stored in /etc/gitconfig.

Create a project specific config, you have to execute this under the project's directory:

$ git config user.name "John Doe" 

Create a global config:

$ git config --global user.name "John Doe"

Create a system config:

$ git config --system user.name "John Doe" 

And as you may guess, project overrides global and global overrides system.

Note: Project configs are local to just one particular copy/clone of this particular repo, and need to be reapplied if the repo is recloned clean from the remote. It changes a local file that is not sent to the remote with a commit/push.