How to setup extra ssh keys when using different

multiple-ssh-keys-for-git.md

Setup multiple SSH Keys for different github accounts

For osx

Create different public key

Create different ssh key according the article: Generate new SSH key

$ ssh-keygen -t ed25519 -C "my_email@provider.com"

for example, 2 keys created at:

~/.ssh/id_rsa
~/.ssh/id_other-account

then, add these two keys as following

$ ssh-add -K ~/.ssh/id_rsa
$ ssh-add -K ~/.ssh/id_other-account

-K saves it to the keychain

You can delete ALL cached keys with

$ ssh-add -D

You can check saved keys with

$ ssh-add -l

Modify the ssh config

$ vim ~/.ssh/config

Then add:

# Main account
Host github.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_rsa
  IdentitiesOnly yes

# Other account
Host github.com-other-account
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_other-account
  IdentitiesOnly yes

Host *
  AddKeysToAgent yes
  UseKeychain yes

The last bit is only needed if you supplied -K with ssh-add.
So you won't have to re-type your password after restart computer

Of course you can use a single key for other git providers as well, like gitlab or bitbucket.

Clone/update the repo

When cloning a repo, provide the host of the account you want to use

$ git clone git@github.com-other-account:<username>/<repo>.git targetdir

If you need to update an existing repo, you can update the targetdir/.git/config file by typing

$ git remote set-url origin git@<host-in-ssh-config>:<username>/<repo>

Or manually edit the config file

Automaticly match account with organization

If you use your "other-account" only for one organization, say "acme-org" you can supply the line below so that it is automatically used when cloning.

git config --global url."git@github.com-other-account:acme-org/".insteadOf "git@github.com:acme-org/"

Set git username

This is not required for access, but used in commits.
You can set this globally for your main account and locally for your "other-account".

Set globally for your main account:

$ git config --global user.name "Jorn"
$ git config --global user.email "my_email@provider.com"

Set in project for the other account:

$ git config user.name "Jorn"
$ git config user.email "my_email@some-project.com" 

If there are multiple repo's connected to the other account this becomes tedious.
You can extend the global config by a directory match pattern:

~/.gitconfig

[user]
    name = Jorn
    email = my_email@provider.com

# note the trailing /
[includeIf "gitdir:~/workdir/"]
    path = ~/workdir/.gitconfig

~/workdir/.gitconfig

[user]
    email = my_email@some-project.com

This will enable the alternate email address for ~/workdir/ recursively.

Ready, set, go!

Credits:

• https://gist.github.com/jexchan/2351996
• https://www.freecodecamp.org/news/how-to-manage-multiple-ssh-keys/
• https://stackoverflow.com/questions/4220416/can-i-specify-multiple-users-for-myself-in-gitconfig/43654115#43654115
• https://docs.github.com/en/account-and-profile/how-tos/account-management/managing-multiple-accounts#contributing-to-multiple-accounts-using-ssh-and-multiple-keys

Note that [includeIf "gitdir:~/workdir/"] should end with a / to catch all sub dirs.