Git Version Control

Install

Mac

1. Install Apple Xcode developer tools
   • xcode-select --install
2. Download Homebrew: https://brew.sh/
   • Homebrew helps you easily manage installs on a Mac from command-line
3. Install git using homebrew
   
   • brew install git

Windows

1. From PowerShell, open your Ubuntu Linux distribution with wsl and run the command apt install git
   • 
   • NOTE: If you forgot your password (or were not prompted to set one upon initial WSL install), you can reset your password using the following steps:
     • Exit the Linux distribution you are in with the command exit
     • Re-enter the Linux distribution as the root user wsl -u root
     • Enter the command passwd {your username} and type in the new password
       • 
       • NOTE: your username is what you saw in the command prompt when you weren't at the root
         • 
     • Exit the Linux Distribution with exit

Red Hat Linux

1. Switch to the super user (a.k.a root user)
   • sudo su
2. Enter your password
3. Install git
   • yum install git
4. Switch back to a normal user
   • exit

Set Git Username and Email

In order to commit/ push code to Git you must configure your username and email.

1. git config --global user.name {your username}
2. git config --global user.email {your email}

Configure SSH Auth

To easily authenticate with Github/ Bitbucket (i.e. not need to enter your username/ password every time you pull/push to the repo) you can set up SSH authentication.

Setting up git authentication on a personal machine (i.e. one that only you will be using) is very simple. However, if multiple user may be using the machine (i.e. a Linux Machine shared by a development team) you will want to follow a few additional step so that commits can be distinguished by user.

Personal Machine SSH Auth

1. Create an SSH key pair with the command ssh-keygen and press enter to accept all the default
   • 
2. Copy the content of the id_rsa.pub file using the cat {path to your file} command
   • For example, cat ~/.ssh/id_rsa.pub
3. See the Machine Type Agnostic Steps section for remaining steps

Shared Machine SSH Auth

1. Create an SSH key pair with the command ssh-keygen, adding your git profile to the end of the id_rsa file name instead of accepting all default
   • For example: Users/jillvillany/.ssh/id_rsa_jillvillany
     • 
2. Navigate to where the ssh key pair was created using the cd {path to ssh folder} command
   • For example: cd Users/jillvillany/.ssh
3. Create the config file

   touch config
   vim config
   

   • NOTE: Git username vairable is case sensitive
   • If using Github, add the below to your config file:

     Host github-{git username}
      HostName github.com
      IdentityFile ~/.ssh/id_rsa_{git username}
      IdentitiesOnly yes
     

   • If using Github Enterprise (i.e. IBM), add the below to yuur config file:

     Host github-{git username}
         HostName github.ibm.com
         IdentityFile ~/.ssh/id_rsa_{git username}
         IdentitiesOnly yes
     

   • If Bitbucket:

     Host bitbucket.org-{git username}
      HostName bitbucket.org
      User git
      IdentityFile ~/.ssh/id_rsa_{git username}
      IdentitiesOnly yes
     

   • NOTE: If you have other users to add, create similar entries below in the file
4. Copy the contents of the id_rsa_{git username}.pub file using the cat id_rsa_{git username}.pub command

Machine Type Agnostic Steps

1. Add SSH key in Github or Bitbucket
   • In Github:
     • Navigate to Settings > SSH and GPG keys
     • 
     • Click New SSH key and add the contents of your id_rsa_{git username}.pub file in the key field
   • In Bitbucket:
     • Navigate to personal settings
     • 
     • Select SSH Key > Add Key add the contents of your id_rsa_{git username}.pub file in the key field
2. Add the SSH key to the SSH agent

   ssh-add ~/.ssh/id_rsa_{git username}
   

   • NOTE: if you get an error about connecting to the ssh agent, you need to start the agent in the background with eval $(ssh-agent -s)
   • 
3. Test your SSH connection
   • If on a personal machine:
     • Github: ssh -T git@github.com
       • 
     • Github Enterprise (i.e. IBM): ssh -T git@github.ibm.com
     • Bitbucket: ssh -T git@bitbucket.org
   • If on a shared machine:
     • Github: ssh -T git@github-{your username}
     • Github Enterprise (i.e. IBM): ssh -T git@github.ibm-{your username}
     • Bitbucket: ssh -T git@bitbucket.org-{your username}