How to setup a git server on Ubuntu 20.04

how-to-setup-git-server.md

Installing Git server

First, lets update our packages list by running:

sudo apt update

To install Git, run the following command:

sudo apt install git

Verify that Git was successfully installed on your system:

git version

It’s highly recommended to create a new Linux user for managing the Git repositories, run:

sudo useradd -m -r -U -d /home/git-repos git

The home directory of git user is located at /home/git-repos. To increase security, we’ll create an ssh key to log in to the git user.

Switch to the log-in session of git user by running:

sudo su - git

To create the SSH directory and file for holding the authorized ssh key for git user, run the following commands:

mkdir -p ~/.ssh
chmod 700 ~/.ssh
touch ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys

Once, the server was successfully set-up, it’s time to create a new git repository:

git init --bare ~/test-teo.git

Configuring Git repository

Now, we have to add our local user’s public SSH key to the authorized_keys file of the git user. If we already have generated an SSH key for our local user, we can skip the following step:

ssh-keygen -t rsa

Now, we can copy our public SSH key to the server by running (replace <user> and <host>):

ssh-copy-id -i ~/.ssh/id_rsa.pub <user>@<host>

Note: Manually copy the public ssh key to the server

• Sub-step 1: Get the public key

  Ask the end user to provide the public key by typing the following command:

  cat ~/.ssh/id_rsa.pub

  It will show a long random string starting with ssh-rsa:

  ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQ3GIJzTX7J6zsCrywcjAM/7Kq3O9ZIvDw2OFOSXAFVqilSFNkHlefm1iMtPeqsIBp2t9cbGUf55xNDULz/bD/4BCV43yZ5lh0cUYuXALg9NI29ui7PEGReXjSpNwUD6ceN/78YOK41KAcecq+SS0bJ4b4amKZIJG3JWm49NWvoo0hdM71sblF956IXY3cRLcTjPlQ84mChKL1X7+D645c7O4Z1N3KtL7l5nVKSG81ejkeZsGFzJFNqvr5DuHdDL5FAudW23me3BDmrM9ifUmt1a00mWci/1qUlaVFft085yvVq7KZbF2OP2NQACUkwfwh+iSTP username@hostname

  Now we can copy the above public SSH key into the authorized_keys file of the git user.

• Sub-step 2: Create ssh directory in the git user’s home directory (as a sysadmin)

  Keep in mind that we have to create these new directories and files in the git user’s home directory, not your own (root/sysadmin).

  mkdir -p /home/git-repos/.ssh && touch /home/git-repos/.ssh/authorized_keys

  Now open this /home/git-repos/.ssh/authorized_keys file with a text editor like Vim and add the public key of the user here:

  vim /home/git-repos/.ssh/authorized_keys

  Save and close the file. It’s almost ready.

• Sub-step 3: Set appropriate permission to the file Having appropriate file permission on the ssh file is very important otherwise we’ll see errors like Permission denied (publickey).

  First, make sure to set the correct file permissions:

  chmod 700 /home/git-repos/.ssh && chmod 600 /home/git-repos/.ssh/authorized_keys

  We created those file with either root or our own admin accounts for some other user. So we need to change the ownership to the git user:

  chown -R git:git /home/git-repos/.ssh

On our local Ubuntu 20.04 machine, assuming that you already had an unversioned directory, for example, ~/go. Change the current directory to it:

cd ~/go
git init .

Next, you have to add a git remote to track your local repository on Git server:

git remote add origin git@git-server-ip-address:test-teo.git

Verify that your Git server was successfully installed and configured, run the following command:

cd ~/go
touch README
git add .
git commit -m "Add file Readme"
git push origin master