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Lab 5 - Introduction Amazon Web Services (AWS)

Overview​

This week's lab will cover the following:

  • Investigating the AWS Learner Lab.
  • Using the AWS Console interface.
  • Modifying Virtual Private Cloud (VPC) Security Groups.
  • Exploring Amazon Elastic Cloud Compute (EC2).
  • Adding an instance in AWS.
  • Creating SSH key pairs & paired key encryption.
  • Creating a Dotfiles repository in GitHub.

Investigating the AWS Learner Lab​

You should have received an email (in your Seneca Polytechnic email) from your professor inviting you to participate in the AWS Academy Learner Lab. If you have received and accepted this invitation you may proceed with this lab. If you have not received this invitation you should contact your professor immediately. You may continue with the rest of the lab once you have received the invitation. Here is a sample email.

AWS Invitation

The AWS Learner Lab provides a sandbox environment where you can build, configure and deploy AWS assets such as instances. There are some limitations as to what you can do, however it provides all the functionality we require for this course. You are limited to $100 credit at no cost within the learner lab. Once this runs out your learner lab will be disabled. Additionally, there is no way to add funds to this pool. If you follow the lab instructions properly you should not have any issues.

Once you have accepted your invitation and logged into the AWS Learner Lab navigate to Courses (on the left hand side) > Modules > Learner Lab. You should see a screen that looks like the following: AWS Learner Lab home

Some important things to note on this screen:

Start Lab: Starts the Learner Lab environment.

Stop Lab: Stops the Learner Lab environment.

Used $0 of $50: Shows the balance used of your $50 credit. If this hits $50 of $50 used, your learner lab is disabled. Be careful.

AWS with a red dot next to it: Once your lab has started, this will turn green. You can then click on this to open the environment.

Using the AWS Console interface​

Start your session in the Learner Lab by clicking on the Start Lab button. Once the red dot has turned green, click on it to enter the Learner Lab. This will take you to the AWS Console (depicted below), which will be where you will do most of your work. It also mirrors a production AWS interface. Note: Your screen may not look 100% identical to the one depicted, but should be mostly the same. AWS Console

If you click on Services in the top left corner (beside the AWS logo), you will see all the services you can configure in the AWS learner lab. Common ones we will use are EC2 and VPC. You can search for these in the search bar, or browse the categories. Recently visited services will show up under the heading Recently visited. If you hover over any service you will see a greyed out star to the left of the name. You can click on this to add it to your favourites for easy access.

Modifying VPC Security Groups​

An Amazon Virtual Private Cloud (VPC) is a dedicated virtual network within AWS' public cloud. It work similar to how a traditional network does in a data center. w3schools has some additional information.

Security Group settings are located in the left side navigation under Network & Security > Security Groups. Click on Security Groups.

Your screen should look like the following: AWS Security Groups

Make sure the box beside your Security Group is checked. Click on InBound rules > Edit InBound Rules and add the following rule:

  • Type: SSH or Port Range: 22 (both will accomplish the same thing)
  • The box beside the magnifying glass: 0.0.0.0/0
  • Click Save Rules

This will allow incoming SSH connections from anywhere. We will use this in the next part to connect to your instance. The screenshot below shows what your inbound rules should look like: AWS Inbound Rules - Lab 1

Exploring Amazon Elastic Cloud Compute (EC2)​

EC2 is where you will end up spending the most amount of time configuring things in this course. From here you can do things like launch instances, manage networking services and much more. To access EC2, click on Services (top left corner beside the AWS icon), and navigate to Compute > EC2. You may wish to add this to your favourites for easy access by hovering over and clicking the star. Your initial screen should look something like the following. w3schools has some additional information

AWS EC2

Adding an instance in AWS​

Click on Launch instance just below the Resources pane. From the Launch an instance screen, select the following options:

  • Name: first
  • OS: Ubuntu
  • Amazon Machine Image(AMI): Make sure Ubuntu Sever 24.04 is selected

Creating SSH key pairs & using public key cryptography​

Under Key pair (login) click Create new key pair. Give it the name ops345, accept the rest of the defaults and click "Create key pair".

Important: Do not lose your key pair or you will be unable to connect to your instance using SSH.

Under Network Settings click Select existing security group. Click the dropdown and check the default. Click Launch instance. Once it has finished completing (you should see a success message), click Connect to instance.

Note there are a few ways to connect to your instance from here. The easiest to use are:

  • EC2 Instance Connect: Allows you to connect to your instance from within your web browser.
  • SSH client: Allows you to connect to your instance using the SSH key pair.

You will be accessing our new Linux VM remotely using SSH, which is a command-line (CLI) only protocol.

Requirements: An SSH Client​

  • Windows: Use the built-in Command Prompt application.
  • macOS/Linux: Use the built-in Terminal application.

For all clients​

  • In the Linux EC2 Instance summary page, click the Connect button.
  • In the new Connect to instance page, click on the SSH client tab.
  • Copy the example command near the bottom of the page. (Use your example command)
  • Choose the proper OS below and continue.

On Windows, Using Command Prompt:​

  • Open Command Prompt.
  • Change directories to your default Downloads folder with the following command: cd Downloads (If you saved your .pem file elsewhere, navigate there. Or move the .pem file into Downloads.)
  • Paste the example command from the Connect to instance page, and press Enter.
  • The SSH command will ask you to confirm connecting. Type yes and press Enter.
  • If login is successful, you should see a prompt like this: ubuntu@ip-172-31-91-76:~$
  • To quit, type exit.

On macOS/Linux, Using Terminal:​

  • Open Terminal.
  • Change directories to your default Downloads folder with the following command: cd Downloads (If you saved your .pem file elsewhere, navigate there. Or move the .pem file into Downloads.)
  • Change the file permissions of your .pem file with this command: chmod 400 *.pem
  • Paste the example command from the Connect to instance page, and press Enter.
  • The SSH command will ask you to confirm connecting. Type yes and press Enter.
  • If login is successful, you should see a prompt like this: ubuntu@ip-172-31-91-76:~$

Creating a dotfiles repository in GitHub​

A GitHub dotfiles repository is used to store and manage your configuration files (often called "dotfiles" because their filenames start with a dot, e.g., .bashrc, .vimrc, .gitconfig). These files are used to customize your development environment. By keeping them in a GitHub repository, you can easily share your configurations across different machines and with other developers. This practice helps in maintaining consistency in your development setup and makes it easier to set up new environments quickly. A dotfiles repo can also be used to host scripts you wish run upon the creation of any Codespace you create using your GitHub account (ie account wide).

You are going to create a dotfiles repository using an existing template repository. Template repositories are used for creating new repositories from a common base. This is how the GitHub Classroom assignments you have accepted have worked. The template repository has a script in it that will add your AWS ssh key (.pem file) to any Codespace you create allowing you to access your instance via SSH from the terminal in Codespaces.

  • In your web browser, navigate to the dotfiles template repository in the OSL745 organization.
  • In the top right corner, click Use this template
  • Make sure owner is set to your GitHub user, and provide the repository name as dotfiles. Your screen should look similar the picture below. You can set it's visibility to private if you wish. With a private repo, no one will even see it exists. Creating a dotfiles repo

Adding your .pem file as a GitHub secret​

Browse to your dotfiles repository.

  • Click on Settings
  • Click on Secrets and variables
  • Click on Codespaces
  • Click the Green button labelled New repository secret
  • Add the secret With the following
    • name SSH_KEY
    • In the Secret field, paste in the contents of your .pem file. You can use cat from your local command line (yes, even from the Windows Terminal / PowerShell) and copy/paste.

Your screen should look as follows (note, in the screenshot the secret field has been left empty) New Repository Secret New Repository Secret

  • Click the green button labelled Add secret

Automatically installing your dotfiles repository for every Codespace you create​

In your web browser, navigate to your GitHub Profile.

  • Click on your GitHub profile (top right corner)
  • Click on Settings
  • Click on Codespaces

Under Dotfiles:

  • Check the box beside Automatically install dotfiles
  • Browse to your dotfiles repository. Note, it may automatically populate.

Connecting to your AWS instance from the terminal in Codespaces​

You may need to rebuild the container for any existing Codespaces you own. Note: Keys added via your dotfiles repo will be installed over top of per-repo keys with this configuration.

Launch Codespaces from any of your previous GitHub Classroom assignments (or even for your dotfiles repo). In the terminal (in the bottom) copy paste the SSH command from EC2 Instance Connect and remove the path to the key. Since the script wrote your private key to the default location, you do not need to specify the path to the key. It should look similar to following.

ssh ubuntu@ec2-23-20-90-70.compute-1.amazonaws.com

Once you have confirmed this works, you can logout from your Codespaces terminal and shut everything down (Codespaces and the AWS Learner Lab). For proof, show your professor a successful connection to your instance (either via ec2 instance connect, SSH from Codespaces or both).

Lab 5 Sign-Off (Show Instructor)​

Show your professor a successful connection to your instance. The following Exploration Questions are for furthering your knowledge only, and may appear on quizzes or tests at any time later in this course.

Exploration Questions​

  1. How do you start/stop the AWS learner lab?
  2. How do you enter the AWS learner lab once you have started it?
  3. What happens to your learner lab if your credits hit $50 of $50 used?
  4. Where do you go to edit networking configuration options such as security groups?
  5. Where do you go to launch an instance?
  6. What is an instance?
  7. What command do you use to access an instance in AWS from your command line?
  8. What is public-key cryptography?