Setting multiple GitHub accounts & ssh keys

Sometimes, we have multiple projects using different GitHub accounts and so, ssh keys. When come the moment to set and use a second account / ssh key, the first one will "always" be used by default. The solution is to configure ssh agent and then use it the right way with git commands.

Step 1: ssh keys

Create a ssh key:

ssh-keygen -t ed25519 -C "[email protected]"
# Enter a file name (eg.: id_ed25519_work)

Start the user-agent before adding key:

eval "$(ssh-agent -s)"
# Agent pid 59566

Add the key to the user-agent:

ssh-add ~/.ssh/id_ed25519_work

Checking if the key is registered to the user-agent:

ssh-add -l
# 2048 6d:65:b9:3b:ff:9c:5a:54:1c:2f:6a:f7:44:03:84:3f [email protected] (ed25519)

Modifying ssh key file permissions:

# For public key: 644 (-rw-r--r--)
chmod 644 ./id_ed25519_work.pub
# For private key: 600 (-rw-------)
chmod 600 ./id_ed25519_work.pub
# Checking permissions octal level
stat -c "%a %n" *

Step 2: ssh config

Set up multiple ssh profiles by creating/modifying ~/.ssh/config file:

Default GitHub

Host github.com
    HostName github.com
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/id_rsa

"Work" GitHub

Host work.github.com
    User workerName
    HostName github.com
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/id_ed25519_work

| Note the slightly differing Host values

Step 3: test

Verifying the ssh connection with the correct keys:

ssh -T [email protected]
# Hi <userName>! You've successfully authenticated, but GitHub does not provide shell access.
ssh -T [email protected]
# Hi workerName! You've successfully authenticated, but GitHub does not provide shell access.

| Note the correspondence between [email protected] and the .ssh/config Host work.github.com

Step 4: clone a a repository

Now it's possible to clone a repository using a specific ssh config/key.

git clone [email protected]:userName/projectName.git

Similar solutions

Solutions that will maybe works when there are multiple ssh keys, but only one account.

Ssh cloning by specifying the ssh key:

git clone -c core.sshCommand="/usr/bin/ssh -i ~/.ssh/id_ed25519_work" [email protected]:userName/projectName.git

Modifying an existing project by forcing a key to be used:

git config --local core.sshCommand "/usr/bin/ssh -i ~/.ssh/id_ed25519_work"

links

• Create a ssh key
• Add ssh key on Github
• Test ssh connection
• Multiple GitHub Accounts & SSH Config