Lab: Setting up your environment

The purpose of this lab is to provide you with step-by-step instructions for setting up your local environment and to get you comfortable with the command line and ancillary tools that you will use constantly in this course.

You must read all the instructions carefully before beginning and lab/assignment. Follow the instructions step-by-step. Do not jump around. This lab and almost every other lab/assignments in this course are designed to be followed in a linear manner. If you don't, then some later items may not work. Also, the screenshots may look slightly different than what you are seeing given things change.

After completing this lab, you will be able to:

• Create your public/private ssh key pair, know where these files are located, and know how to extract their contents
• Accept a GitHub Classroom assignment/lab, how to clone it on a remote machine, and how to submit an assignment/lab
• Connect to a remote machine using ssh
• Use ssh agent forwarding to be able to work with your GitHub repositories in a remote machine
• Work with command line text editors
• Download a file using the command line
• Do some data wrangling with the command line

Definitions

Term(s)	Definition
Terminal shell command line	Terms used interchangeably to refer to opening up a terminal session
command prompt	The terminal position where you enter a command. Prompts for different systems may look different.
local machine	The machine you are interacting with (desktop, laptop)
remote machine	The machine you connect to

WiFi (for Georgetown Students when on campus)

If you are a Georgetown student, and you are on campus, you must be connected to Saxanet wifi. Otherwise you will not be able to connect to your cloud resources or remote machines.

Step 1 - Terminal Setup

Windows Users

PowerShell

Windows users will be using the Windows Powershell. Windows Powershell is most likely installed if you have Windows 10. If you don't have Powershell, take a look at this article that explains how to install it.

You can find Powershell by typing "Powershell" into the search bar:

Once Powershell is running, this is your terminal:

Additional Powershell Configuration (you must do this)

You need to perform this sequence of steps only once to be able to use agent forwarding which is explained further in the lab.

1. Exit Powershell if running
2. Start a new Powershell session using run as Administrator
3. Type Get-Service ssh-agent | Set-Service -StartupType Automatic
4. Close Admin Powershell

Mac and Linux Users

For Mac and Linux users, you will open up the Terminal. Macs and Linux have a built in Terminal. I prefer using iTerm app as another Terminal application for your Mac. I’ve been using it for years and I love it. This is not required, but truly recommended.

In Linux, most distributions will open the terminal by using Ctrl-Alt-T.

Step 2 - SSH Keypair Setup

2a) Create your ssh key pair

NOTE: You only need to create your ssh public/private keypair one time only. If you already have a public/private keypair on your laptop let us know.

1. Open the terminal for your operating system if not already open. By default, every time you open a terminal it will open in your home directory.
2. At the command prompt, type: ssh-keygen -t rsa -b 2048, press enter
3. You will see this prompt, just press enter

Generating public/private rsa key pair.
Enter file in which to save the key (/home/User/.ssh/id_rsa):

1. You will see this prompt, just press enter

Created directory '/home/User/.ssh'.
Enter passphrase (empty for no passphrase):

1. You will see this prompt, just press enter

Enter same passphrase again:

1. You will see these messages (your randomart will look different) and your keypair has been created.

Your identification has been saved in /home/User/.ssh/id_rsa.
Your public key has been saved in /home/User/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:xPJtMLmJSO73x/NQo3qMpqF6r6St4ONmshS8QZqfmHA User@WinDev1802Eval
The key's randomart image is:
+---[RSA 2048]----+
|                 |
|       . .       |
| .  . . *        |
|+. o . = *       |
|++E o . S o o    |
|.=+o     . o .   |
|+oo o o  +o      |
|+= +.o oo.*.     |
|*+=++ooooo o.    |
+----[SHA256]-----+

2b) See the contents of your key files

1. Open a terminal if not already open

2. Change to the .ssh directory. The .ssh directory is a hidden directory inside your home directory. If you list your files using ls you won't see it. To see all files, use ls -la. To change into the directory, use the cd command: cd .ssh.

3. Type pwd (print working directory) which prints your current working directory to make sure you are in the ~/.ssh directory.

   On a Mac, you should see something like:

   $ pwd
   /Users/myusername/.ssh
   

   If you are using Powershell in Windows you will see something like:

   PS C:\Users\marck> pwd
   
   Path
   ----
   C:\Users\marck
   
   PS C:\Users\marck>
   

   If you are using Linux you'll see something like

   $ pwd
   /home/myusername/.ssh
   

4. Type ls -la to list the files in the directory. What is displayed is my output and yours may look different.

   • The id_rsa is your private key and this file will not leave your computer. Treat this file as a password and don't share it with anyone.
   • The id_rsa.pub file is the public key, whose contents we will upload to cloud services and other services so you authenticate with your pricate key
   • The known_hosts is a file that gets generated as you connect to different remote systems
   • You will not have a config file unless you have already created one.

   $ ls -la
   total 32
   drwxr-xr-x   6 marck  staff   192 May 29 20:39 .
   drwxr-xr-x+ 75 marck  staff  2400 May 30 13:35 ..
   -rw-r--r--@  1 marck  staff   181 May 29 15:50 config
   -r--------@  1 marck  staff  3243 May 29 15:50 id_rsa
   -rw-r--r--@  1 marck  staff   742 May 29 15:50 id_rsa.pub
   -rw-r--r--   1 marck  staff   363 May 29 20:42 known_hosts
   

5. View the contents of your public_key file: cat id_rsa.pub (what is shown is my public key, yours will be different.)

   $ cat id_rsa.pub
   ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCnKuIRXwZu0JZH0/Q2XNrYYTaJT7bMtXGhGQaSSOZs6MhQ4SkSbHiygO7RauQf741buLnASzY27GKMMMml6InwfxJWrF60KhNK0r869POQkuZa9v9/cmYcEIzmAJe1xRPABEZ2yfbTG9Wq4sg9cU0mwt1Bx7wiN4QNf0Bak62EC8JWTbcKLduuzO1zabIb5xW9gfR9b4K3HwmqRLl18S8bNsfYQZfvtlwd0mCWQUeuEGbDOgqh//nLIj6DeXdyxbD5xrz79iOAuAK2nXAjNCEtKpxNGQr2Py7aWQjlH+U5laDEHVg4hzmBY7yoZ5eC3Ye45yPqpQA1y8JrbXVhPJRP User@WinDev1802Eval
   

6. Open a text editor (Notepad on Windows or Textpad on Mac, NOT MICROSOFT WORD) and select the output of your terminal from the ssh-rsa beginning all the way to the end, and paste it in your text editor as-is. We will use this in the next step. You can also just leave it here and copy/paste from your terminal screen.

Step 3 - GitHub Setup

3a) Create a GitHub Account if you do not already have one

Go to www.github.com to create a GitHub account if you do not already have one. Your username has to be globally unique, and the email address you use to register GitHub can be any email address you own.

3b) Upload your Public key to GitHub

1. Log into to your GitHub account if you are not already logged in
2. Click on your profile icon on the top-right of the screen and select Settings from the dropdown
3. Click on SSH and GPG keys from the left hand menu
4. Click on the New SSH key button on the top-right
5. Give your key a name. This is just a name and is meaningful to you.
6. Paste the contents of the public key in the Key box, and click the Add SSH Key button

3c) Test that your ssh key works with GitHub

1. Open a terminal if not already open on your laptop
2. At the command prompt, type ssh -T git@github.com and press enter to test. If it works, you will see something like this, with your GitHub username:

The authenticity of host 'github.com (192.30.253.112)' can't be established.
RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'github.com,192.30.253.112' (RSA) to the list of known hosts.
Hi wahalulu! You've successfully authenticated, but GitHub does not provide shell access.

You are now ready to use ssh authentication with GitHub.

3d) Create a Personal Access Token

1. Log into to your GitHub account if you are not already logged in

2. Click on your profile icon on the top-right of the screen and select Settings from the dropdown

3. Click Developer settings

4. Click the Personal access tokens tab

5. Click the Generate new token button

6. Enter a token description (you can call it big-data-class)

7. Select the repo permission, and then click the Generate token button

   

8. Copy the token and save it in a text file. You will need this token later and if you lose it you will need to re-generate a token

Step 4 - GitHub Classroom Sample Assignment/Lab

We are using GitHub Classroom as the platform for labs and assignments. Working with GitHub classroom is very easy. When an assignment/lab is created, we will provide you a link to the assignment in the LMS platform (Canvas, Blackboard, etc.).

1. Check the GitHub Classroom Assignment URL in the LMS. Click on it.

2. The first time you access a classroom assignment, you will be taken to the Join the Classroom page. In this page, scroll through the list of names and find yours. Make sure you click on yours and your only. This will happen only once. You need to be logged into GitHub as well.

   

3. Click OK in the confirmation popup:

   

4. In future assignments, you will be taken directly to the Accept the Assignment page. Here, click on the green button:

   

5. An assignment confirmation page will show and GitHub will begin the process of creating and a repository with the contents of the assignment. You will be notified when the creation of your repository is complete

   Each student has their own repository created for every lab/assignment. The repository name usually includes your GitHub account name as part of the name of the repo. Your repository is private and must remain private. Only the intructional team and the individual student have access to each student's repo.

6. You are now ready to visit your repository and follow the instructions.