# Git - Create Operation In this chapter, we will see how to create a remote Git repository; from now on, we will refer to it as Git Server. We need a Git server to allow team collaboration. ## Create New User ``` # add new group [root@CentOS ~]# groupadd dev # add new user [root@CentOS ~]# useradd -G devs -d /home/gituser -m -s /bin/bash gituser # change password [root@CentOS ~]# passwd gituser ```

The above command will produce the following result. ``` Changing password for user gituser. New password: Retype new password: passwd: all authentication token updated successfully. ```

## Create a Bare Repository Let us initialize a new repository by using **init** command followed by **--bare** option. It initializes the repository without a working directory. By convention, the bare repository must be named as **.git**. ``` [gituser@CentOS ~]$ pwd /home/gituser [gituser@CentOS ~]$ mkdir project.git [gituser@CentOS ~]$ cd project.git/ [gituser@CentOS project.git]$ ls [gituser@CentOS project.git]$ git --bare init Initialized empty Git repository in /home/gituser-m/project.git/ [gituser@CentOS project.git]$ ls branches config description HEAD hooks info objects refs ```

## Generate Public/Private RSA Key Pair Let us walk through the process of configuring a Git server, **ssh-keygen** utility generates public/private RSA key pair, that we will use for user authentication. Open a terminal and enter the following command and just press enter for each input. After successful completion, it will create a **.ssh** directory inside the home directory. ``` tom@CentOS ~]$ pwd /home/tom [tom@CentOS ~]$ ssh-keygen ```

The above command will produce the following result. ``` Generating public/private rsa key pair. Enter file in which to save the key (/home/tom/.ssh/id_rsa): Press Enter Only Created directory '/home/tom/.ssh'. Enter passphrase (empty for no passphrase): ---------------> Press Enter Only Enter same passphrase again: ------------------------------> Press Enter Only Your identification has been saved in /home/tom/.ssh/id_rsa. Your public key has been saved in /home/tom/.ssh/id_rsa.pub. The key fingerprint is: df:93:8c:a1:b8:b7:67:69:3a:1f:65:e8:0e:e9:25:a1 tom@CentOS The key's randomart image is: +--[ RSA 2048]----+ | | | | | | | . | | Soo | | o*B. | | E = *.= | | oo==. . | | ..+Oo | +-----------------+ ```

**ssh-keygen** has generated two keys, first one is private (i.e., id\_rsa) and the second one is public (i.e., id\_rsa.pub). **Note:** Never share your PRIVATE KEY with others. ## Adding Keys to authorized\_keys Suppose there are two developers working on a project, namely Tom and Jerry. Both users have generated public keys. Let us see how to use these keys for authentication. Tom added his public key to the server by using **ssh-copy-id** command as given below − ``` [tom@CentOS ~]$ pwd /home/tom [tom@CentOS ~]$ ssh-copy-id -i ~/.ssh/id_rsa.pub gituser@git.server.com ```

The above command will produce the following result. ``` gituser@git.server.com's password: Now try logging into the machine, with "ssh 'gituser@git.server.com'", and check in: .ssh/authorized_keys to make sure we haven't added extra keys that you weren't expecting. ```

Similarly, Jerry added his public key to the server by using ssh-copy-id command. ``` [jerry@CentOS ~]$ pwd /home/jerry [jerry@CentOS ~]$ ssh-copy-id -i ~/.ssh/id_rsa gituser@git.server.com ```

## Push Changes to the Repository We have created a bare repository on the server and allowed access for two users. From now on, Tom and Jerry can push their changes to the repository by adding it as a remote. Git init command creates **.git** directory to store metadata about the repository every time it reads the configuration from the **.git/config** file. Tom creates a new directory, adds README file, and commits his change as initial commit. After commit, he verifies the commit message by running the **git log** command. ``` [tom@CentOS ~]$ pwd /home/tom [tom@CentOS ~]$ mkdir tom_repo [tom@CentOS ~]$ cd tom_repo/ [tom@CentOS tom_repo]$ git init Initialized empty Git repository in /home/tom/tom_repo/.git/ [tom@CentOS tom_repo]$ echo 'TODO: Add contents for README' > README [tom@CentOS tom_repo]$ git status -s ?? README [tom@CentOS tom_repo]$ git add . [tom@CentOS tom_repo]$ git status -s A README [tom@CentOS tom_repo]$ git commit -m 'Initial commit' ```

The above command will produce the following result. ``` [master (root-commit) 19ae206] Initial commit 1 files changed, 1 insertions(+), 0 deletions(-) create mode 100644 README ```

Tom checks the log message by executing the git log command. ``` [tom@CentOS tom_repo]$ git log ```

The above command will produce the following result. ``` commit 19ae20683fc460db7d127cf201a1429523b0e319 Author: Tom Cat Date: Wed Sep 11 07:32:56 2013 +0530 Initial commit ```

Tom committed his changes to the local repository. Now, it’s time to push the changes to the remote repository. But before that, we have to add the repository as a remote, this is a one-time operation. After this, he can safely push the changes to the remote repository. **Note** − By default, Git pushes only to matching branches: For every branch that exists on the local side, the remote side is updated if a branch with the same name already exists there. In our tutorials, every time we push changes to the **origin master** branch, use appropriate branch name according to your requirement. ``` [tom@CentOS tom_repo]$ git remote add origin gituser@git.server.com:project.git [tom@CentOS tom_repo]$ git push origin master ```

The above command will produce the following result. ``` Counting objects: 3, done. Writing objects: 100% (3/3), 242 bytes, done. Total 3 (delta 0), reused 0 (delta 0) To gituser@git.server.com:project.git * [new branch] master −> master ```

Now, the changes are successfully committed to the remote repository.