Handle multiple GitHub accounts on Mac

README.md

Multiple identities

Inspired by article How to Handle Multiple Git Accounts

Work with multiple SSH keys for authorization and commit signing.

Create SSH key

1. Generate a new ssh key

ssh-keygen -t ed25519 -C "firstname@work-email.com"

2. Use custom name, e.g. github-work-user
3. Add passphrase to your password manager (e.g. 1Password)
4. Add ssh key to keychain

ssh-add --apple-use-keychain ~/.ssh/github-work-user

5. Ensure that ssh keys from Github use keychain (otherwise you need to type passphrase for each git commit/push/pull etc)

~/.ssh/config

Host github.com
  AddKeysToAgent yes
  UseKeychain yes

Add ssh key to github

Adding a new SSH key to your GitHub account

1. Copy content of SSH key

pbcopy < ~/.ssh/github-work-user.pub

2. Add the public key as Authentication Key in /settings/keys
3. Add the public key as Signing Key in /settings/keys

Create gitconfig

Global git config points to local configs depending on folder to differentiate git users.

This assumes a folder structure for projects that looks like this. All projects in the work-projects/ folder will use the work github ssh key for authentication and signing.

~/Sites/
  - work-projects/
  - personal-projects/

~/.gitconfig

[gpg]
    format = ssh

# The trailing slashes below are required to match
# any subdirectory and not just the exact path
[includeIf "gitdir:~/Sites/work-projects/"]
    path = ~/.gitconfig.work-user
[includeIf "gitdir:~/Sites/personal-projects/"]
    path = ~/.gitconfig.personal-user

Local git config used for folder ~/Sites/work-projects/ (change name and email)

~/.gitconfig.work-user

[user]
    name = Firstname Lastname
    email = firstname@work-email.com
    signingkey = ~/.ssh/work-user.pub
[commit]
    gpgsign = true
[core]
    sshCommand = "ssh -i ~/.ssh/github-work-user"

Local git config used for folder ~/Sites/personal-projects/ (change name and email)

~/.gitconfig.personal-user

[user]
    name = Firstname Lastname
    email = firstname@lastname.com
    signingkey = ~/.ssh/github-personal-user.pub
[commit]
    gpgsign = true
[core]
    sshCommand = "ssh -i ~/.ssh/github-personal-user"