How to change ssh git user

Question

I am using git with multiple accounts (two) on the same local machine. I created a new ssh-key for the new user (id_rsa_new_user) and I have changed the config file accordingly to allow multiple users, by adding

#new_user's account
Host github.com-new_user
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_rsa_new_user

I logged-in with new git credential by

 git config --local user.name "new_user_ID"
 git config --local user.email "[email protected]"

and I checked that the login is successful by running

git config --global --list

Problem: when I run

ssh -T [email protected]

I am still logged in with the previous user, and this does not allow me to git push or pull properly. How can I authenticate myself via ssh on github with the new user?

Thank you all

Answer 1

When you define an entry in your ~/.ssh/config file, you need to use that entry in your SSH URL, or it won't select the right private key:

ssh -Tv github.com-new_user

No need to add git@ in front of that SSH URL: everyhing is already specified in the config file.

As noted, user.name/user.email are for commit authorship and play no role in authentication (SSH or HTTPS)