Using multiple github accounts with ssh keys

using-multiple-github-accounts-with-ssh-keys.md

Problem

I have two Github accounts: oanhnn (personal) and superman (for work). I want to use both accounts on same computer (without typing password everytime, when doing git push or pull).

Solution

Use ssh keys and define host aliases in ssh config file (each alias for an account).

How to?

1. Generate ssh key pairs for accounts and add them to GitHub accounts.

2. Edit/Create ssh config file (~/.ssh/config):

   # Default github account: oanhnn
   Host github.com
      HostName github.com
      IdentityFile ~/.ssh/oanhnn_private_key
      IdentitiesOnly yes
      
   # Other github account: superman
   Host github-superman
      HostName github.com
      IdentityFile ~/.ssh/superman_private_key
      IdentitiesOnly yes
   

   NOTE: If you use any account frequently, you should use the default hostname (github.com).

3. Add ssh private keys to your agent:

   $ ssh-add ~/.ssh/oanhnn_private_key
   $ ssh-add ~/.ssh/superman_private_key

4. Test your connection

   $ ssh-keyscan github.com >> ~/.ssh/known_hosts
   $ ssh -T git@github.com
   $ ssh -T git@github-superman

   If everything is OK, you will see these messages:

   Hi oanhnn! You've successfully authenticated, but GitHub does not provide shell access.

   Hi superman! You've successfully authenticated, but GitHub does not provide shell access.

5. Now all are set, you need remeber

   git@github-superman:org/project.git => user is superman
   git@github.com:org/project.git.     => user is oanhnn
   

• If you need clone a repository, just do:

$ git clone git@github-superman:org1/project1.git /path/to/project1
$ cd /path/to/project1
$ git config user.email "superman@example.com"
$ git config user.name  "Super Man"

• If you already have the repo set up, after the ssh config instructions, you need change the URL of origin, just do:

$ cd /path/to/project2
$ git remote set-url origin git@github-superman:org2/project2.git
$ git config user.email "superman@example.com"
$ git config user.name  "Super Man"

• If you are creating a new repository on local:

$ cd /path/to/project3
$ git init
$ git remote add origin git@github-superman:org3/project3.git
$ git config user.email "superman@example.com"
$ git config user.name  "Super Man"
$ git add .
$ git commit -m "Initial commit"
$ git push -u origin master

Done! Goodluck!

Addon:

The bash script that prompts for your git account. Thank @davorpa

#!/bin/bash

# silent prompt
read -p 'GIT profile: ' profile

# switch
case $profile in
  superman)
    git config user.email "superman@example.com"
    git config user.name "superman" 
    git config user.signingKey "superman_gpg_public_key"
    ;;
  oanhnn)
    git config user.email "oanhnn@example.com"
    git config user.name "oanhnn" 
    git config user.signingKey "oanhnn_gpg_public_key"
    ;;
  # default case: raise error
  *)
    >&2 echo "ERR: Unknown profile: $profile"
    exit 1
esac

This is super! However I couldnt get the "ssh -T" verify step to work without adding:

Host git@...
        ...
	User git
	...

So something to be awared maybe.

@y-he2 Can you show debug log (ssh -T git@github-alias) in case Host github-alias?

@y-he2 Can you show debug log (ssh -T git@github-alias) in case Host github-alias?

Heres what I could dig up from log with ChatGPT:
(Without "User git") It seems with "ssh -v HostName" even the SHA is matching, but it just give:
...
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
my_os_username @ github.com: Permission denied (publickey).

@y-he2
In your case, ssh will use a username from the logged-in user in the shell.

Host github-alias
   HostName github.com
   IdentityFile ~/.ssh/account1_private_key
   IdentitiesOnly yes

oanhnn@localhost:~$ ssh -vT github-alias
oanhnn@localhost:~$ ssh -vT oanhnn@github.com

Two commands have the same effect.
You should set it up one of two ways.

1 (your solution)

Host github-alias
   HostName github.com
   User git
   IdentityFile ~/.ssh/account1_private_key
   IdentitiesOnly yes

ssh -vT github-alias

2 (like my guide):

Host github-alias
   HostName github.com
   IdentityFile ~/.ssh/account1_private_key
   IdentitiesOnly yes

ssh -vT git@github-alias

@y-he2 In your case, ssh will use a username from the logged-in user in the shell.

Host github-alias
   HostName github.com
   IdentityFile ~/.ssh/account1_private_key
   IdentitiesOnly yes

oanhnn@localhost:~$ ssh -vT github-alias
oanhnn@localhost:~$ ssh -vT oanhnn@github.com

Two commands have the same effect. You should set it up one of two ways.

1 (your solution)

Host github-alias
   HostName github.com
   User git
   IdentityFile ~/.ssh/account1_private_key
   IdentitiesOnly yes

ssh -vT github-alias

2 (like my guide):

Host github-alias
   HostName github.com
   IdentityFile ~/.ssh/account1_private_key
   IdentitiesOnly yes

ssh -vT git@github-alias

Ah that "git@" is obviously what I have been missing, thanks for the clarification!

What about this solution from GitHub docs?
https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-personal-account-on-github/managing-your-personal-account/managing-multiple-accounts#contributing-to-multiple-accounts-using-ssh-and-git_ssh_command

What about this solution from GitHub docs? https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-personal-account-on-github/managing-your-personal-account/managing-multiple-accounts#contributing-to-multiple-accounts-using-ssh-and-git_ssh_command

👍 That solution is good. But the only issue is that typing that command is somewhat long and tiring.

👍 That solution is good. But the only issue is that typing that command is somewhat long and tiring.

That is nota problem at all. Just add an alias for this command, a short one! ☺️

problem with this is that only allows you to use your keys for cloning. But it won't work for installing dependencies that points to ssh@github.com/some/repo.

Thanks bunch it worked for me. Saved my time. Stay happy and posting amazing stuff.

please add one thing in your gist suppose there is an github-superman account so you have to update your package.json like this

{
  "dependencies": {
      ......
      ......
      testRepo: "git+ssh://git@github-superman:org/testRepo.git#main"
  }
}

Very useful!

Now is fixed. (I had the same Host I misunderstood, and put the same Hostname instead of the same Host.
The Host must be differ.

NOTE: If you use any account frequently, you should use the default hostname (github.com)

I have a problem, I have configured the config and add the pair of SSH keys both locally (to agent) and the remote server (GitHub) to two of my GitHub accounts. The pair of keys works fine independently if only have one pair of keys (moving the other outside), but if I have the two pairs of keys in the ~/.ssh/ the test only show me

ssh -T git@github.com
Hi <other-user> ! You've successfully authenticated, but GitHub does not provide shell access.

Here's is my config, I have two "Host github.com" but this should work fine and I think I have used in the past.

# Default github account: david7ce
Host github.com
   HostName github.com
   User git
   IdentityFile ~/.ssh/david7ce

# Second github account: <other-user> 
Host github.com
   HostName github.com
   User git
   IdentityFile ~/.ssh/<other-user> 

You have two keys for the same door, but they're getting mixed up. Let's label one key for your main account and the other for your second account, so each key knows which door to open.

# Default github account: david7ce
Host github.com
   HostName github.com
   User git
   IdentityFile ~/.ssh/david7ce

# Second github account: <other-user> 
Host github-other
   HostName github.com
   User git
   IdentityFile ~/.ssh/<other-user>

@IbroRebronja yes that was the issue, thanks for explanation