This tutorial will show you how to set up a fully fledged Git server using SSH keys for authentication. It will not have a web interface, this will just cover getting Git installed and your access to it set up. We'll use the host "git.droplet.com" in place of the domain you will use for your VPS.
This can be a great option if you want to keep your code private while you work. While open-souce tends to be the status quo, there are some times when you don't want to have your code freely available. An example would be if you are developing a mobile app, especially a paid one. Keep in mind this code can be read by anyone if they know the URL address to use for a clone, but that is only if they know it.
There is one major concern for many and that is a web interface to your repositories. GitHub accomplishes this amazingly well. There are applications that you can install such as Gitosis (https://wiki.archlinux.org/index.php/Gitosis), GitList (http://gofedora.com/insanely-awesome-web-interface-git-repos/), and Goblet (http://git.kaarsemaker.net/). We don't go over those in this tutorial, but if you rely heavily on a graphic interface then you may want to look over those and think about installing one of them as soon as you done installing your Git server.
Next, the VPS will need a user specifically for Git. Most people will simply create a user called "Git", and that is what we'll do for this tutorial but feel free to name this user whatever you'd like.
Setup a Git User and Install Git on your VPS
Log into your VPS, and gain root*:
*Some people feel uncomfortable using root in this manner. If your VPS is set up to use sudo, then do so.
Add the Unix user (not necessarily Git user names) to handle the repositories:
Then give your Git user a password:
Now it's as easy as:
CentOS/Fedora: yum install git
Ubuntu/Debian: apt-get install git
Add your SSH Key to the Access List
At this point, you'll want to be logged in as the Git user. If you haven't already logged in to that user, use this command to switch to it:
Now you need to upload your id_rsa.pub file to your Git user's home directory. Once you have done that, we need let the SSH daemon know what SSH keys to accept. This is done using the authorized keys file, and it resides in the dot folder "ssh". To create this, input:
mkdir ~/.ssh && touch ~/.ssh/authorized_keys
Note: Using the double '&' in your command chains them, so it tells the system to execute the first command and then the second. Using the 'tilde' at the beginning of the path will tell the system to use your home directory, so '~' becomes /home/git/ to your VPS.
We are going to use the 'cat' command, which will take the contents of a file and return them to the command line. We then use the '>>' modifier to do something with that output rather than just print it in your console. Be careful with this, as a single '>' will overwrite all the contents of the second file you specify. A double '>' will append it, so make sure you know what you want to do and in most cases it will be easier to just use ">>" so that you can always delete what you append rather than looking to restore what you mashed over.
Each line in this file is an entry for a key that you wish to have access to this account. To add the key that you just uploaded, type the following, replacing :
cat .ssh/id_rsa.pub | ssh email@example.com "cat >> ~/.ssh/authorized_keys"
Now you can see the key there if you use cat on the authorized key file:
If you want to add others to your access list, they simply need to give you their id_rsa.pub key and you append it to the authorized keys file.
Setup a Local Repository
This is a pretty simple process, you just call the Git command and initialize a bare repository in whichever directory you'd like. Let's say I want to use "My Project" as the project title. When creating the folder, I'd use all lower case, replace any spaces with hyphens, and append ".git" to the name. So "My Project" becomes "my-project.git".
To create that folder as an empty Git repository:
git init --bare my-project.git
Thats it! You now have a Git repository set up on your VPS. Let's move on to how to use it with your local computer.
Using your Git Server from your Local Computer
On Linux or Mac OS, you need to change the remote origin to your newly created server. If you already have a local repo that you want to push to the server, change the remote using this command:
git remote set-url origin firstname.lastname@example.org:my-project.git
If this is a new repository you are setting up, use this:
git init && git remote add origin email@example.com:my-project.git
Now you may add, push, pull, and even clone away knowing that your code is only accessible to yourself.
But what if you want a few trusted people to have access to this server and you want to keep things simple by sorting them by the names of your users? A simple and effective way to do that is to create a folder named after each person, so in the home folder for your Git user list, input:
mkdir user1 user2
Now when you specify the remote repository, it would look like this:
git remote add origin firstname.lastname@example.org:user1/user-project.git
Step 1: Create SSH Public/Private Key Using PuTTY
1. Download and start the puttygen.exe generator (download location: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html).
2. In the "Parameters" section choose SSH2 DSA and press Generate.
3. Move your mouse randomly in the small screen in order to generate the key pairs.
4. Enter a key comment, which will identify the key (useful when you use several SSH keys).
5. Type in the passphrase and confirm it. The passphrase is used to protect your key. You will be asked for it when you connect via SSH.
6. Click "Save private key" and then "Save public key" to save both keys to your disk.