[core]
    repositoryformatversion = 0
    filemode = true
    bare = false
    logallrefupdates = true
[branch "master"]
    remote = origin
    merge = refs/heads/master
[remote "origin"]
    url = git@1.2.3.4:/opt/git/repo.git
    fetch = +refs/heads/*:refs/remotes/origin/*

[ec2-user@ip-10-0-0-111 html]$ sudo git pull
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

ssh git@1.2.3.4

debug1: Offering RSA public key: /home/ec2-user/.ssh/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug1: Authentication succeeded (publickey).

Feb 22 15:45:44 hostname sshd[20142]: Connection from 4.5.6.7 port 50409
Feb 22 15:45:44 hostname sshd[20142]: Found matching RSA key: <fingerprint>
Feb 22 15:45:44 hostname sshd[20142]: Accepted publickey for git from 4.5.6.7 port 50409 ssh2
Feb 22 15:45:44 hostname sshd[20142]: pam_unix(sshd:session): session opened for user git by (uid=0)

Feb 22 15:46:41 hostname sshd[20177]: Connection from 4.5.6.7 port 50410

git pull

sudo ssh git@1.2.3.4

$ whoami
nodejh

# It will generate the ssh key for user: nodejh
$ ssh-keygen -t rsa -C "jianghangscu@gmail.com

# Check that you are connecting to the correct server
$ ssh -T git@github.com
Hi username! You've successfully authenticated...

# change the current user to admin
$ su admin
# generate ssh key for `admin`
$ ssh-keygen -t rsa -C "jianghangscu@gmail.com`