Configure Your AWS CloudShell Environment

Prerequisites

Please read Workshops Organisation if you haven’t done so.

If you are attending a workshop using a Cloud-SPAN AWS account, you don’t need to complete this episode.

If you are self-studying the course or attending a workshop using your AWS account, you must complete either this episode or the previous one: Configure Your Terminal Environment.

To complete this episode you will need:

• to have created and configured your AWS account as described in the episodes Create Your AWS Account and Configure Your AWS Account.
• the login page, username and password of your IAM user account. You can find them in the .csv file you downloaded once you created your IAM account as part of configuring your AWS account.

Introduction

This episode will guide you to configure the AWS CloudShell so that you can run the Scripts therein to create and manage instances in your AWS account.

The AWS CloudShell is a browser-based [Bash] shell that gives you command-line access to your AWS resources in the selected AWS region.

The AWS CloudShell:

• can only be used while you are logged in to the AWS Console.
• has the AWS CLI installed and configured with programmatic access to your AWS account using temporary security credentials based on the credentials to access the AWS Console — this is completely transparent to the user.
• has other software tools installed including: Python, Node.js, git, make, pip, curl, zip, unzip, ssh.
• runs on a Linux AWS instance whose input and output are directed to the browser tab where it is invoked. The instance has 1 GB storage as a Linux file system.
• preserves data and software that you install within your home directory between sessions, but only for 120 days — you will receive warning emails before they are deleted so you can access the AWS CloudShell again. You can install software at system-wide level but you will have to reinstall it every time you access the AWS CloudShell.

For some applications, the key bindings in the AWS CloudShell may be slightly different to the key bindings for same applications in a desktop/laptop machine.

Overview

These are the main steps you will follow to configure your AWS CloudShell environment:

1. Download the Scripts from GitHub.
   You will login to the AWS Console with your IAM user account, launch the AWS CloudShell, and download the Scripts from GitHub.

2. Make the Scripts accessible through the execution path.
   You will configure your AWS CloudShell environment so that the Scripts can be run from any location in the AWS CloudShell file system.

1. Download the Scripts from GitHub

Login to the AWS Console

To access the AWS CloudShell environment and download the Scripts therein, you need to be logged in to the AWS Console with your IAM user account.

Open a new browser window and enter the address of the login page for your account IAM users. The address contains the account alias or your 12-digit account number:

• https://youraccountalias.signin.aws.amazon.com/console
• https://123456789012.signin.aws.amazon.com/console

Enter your IAM username and password. You may also get a Security check to complete.

Once you are logged in, a page like the one below will appear.

IMPORTANT: On the top right, check that the region is set to Ireland. Set it to Ireland if it is not:

An AWS CloudShell that you launch can only operate on resources within a selected region. Since the Cloud-SPAN Amazon Machine Image (AMI) from which you will create AWS instances with the Scripts is located in the Ireland region, you need to select this region before launching the AWS CloudShell.

If you are using an institutional account and you cannot set the region to Ireland, set it to the region which your institutional account is enabled to. Hence you will be installing and running the Scripts in the CloudShell for that region. However, before running the Scripts (in the next lesson), you will need to ask your IT department to copy the Cloud-SPAN AMI to your AWS account.

Note: you can launch multiple AWS CloudShells, each operating on a different region, but this is not needed and hence not covered in the course.

Launch the AWS CloudShell

To launch the AWS CloudShell, click on its icon at the top: the little square with these two characters “>_” inside.

.

You will be presented with the message “Welcome to AWS CloudShell” below.

If you would like to learn more about the AWS CloudShell (software available, installing software, etc.), click on Learn more. A new browser tab will be opened with the online documentation about the AWS CloudShell.

Click on Close to get to the AWS CloudShell.

.

You will now be presented with the AWS CloudShell terminal, like the one below.

It may take up to a couple of minutes for the AWS CloudShell terminal to be ready the first time you open it in a Console session because:

• first, an AWS instance called the environment will be launched — you may see one of these messages (not shown below) “Waiting for the environment to run ..” or “Creating the environment ..”.
• then the terminal program will be run — you may see the message “Preparing your terminal …”.
• finally, you will see the terminal prompt, something like this: [cloudshell-user @ip-10-134-43-226 ~]$ — the numbers in the prompt are the IP address of the instance and may differ every time you open the AWS CloudShell t.

.

Download the Scripts

To download the Scripts, enter or copy-paste the git command below into the CloudShell terminal and press Enter.

Code

git clone https://github.com/Cloud-SPAN/aws-instances.git ~/_tmp_cloudspan_aws

Now enter the command ls -a ~ to list all the files (visible and hidden) in your home directory which is represented by the ~ character:

Code

ls -a ~

The CloudShell terminal should now look similar to the following. If so, you have downloaded the Scripts into the _tmp_cloudspan_aws directory in your home directory.

.

2. Make the Scripts accessible through the execution path

There are many ways to make the Scripts accessible through the execution path. To avoid any conflicts with the current configuration of the CloudShell terminal, we are going to:

1. create a new “bin” directory
2. copy the Scripts to the new bin directory
3. add the new bin directory to the execution path

You can copy-paste the commands below to carry out those three steps using ~/.local/bincsaws as the new bin directory, but please note:

If ~/.local/bincsaws already exists in your environment (which you can check with the command ls ~/.local), choose another name for bincsaws and use the new name instead of bincsaws in the three commands below:

Code

mkdir -p ~/.local/bincsaws
cp ~/_tmp_cloudspan_aws/*.sh  ~/.local/bincsaws
echo "PATH=\"\$HOME/.local/bincsaws:\$PATH\"" >> ~/.bashrc

The command echo ... >> ~/.bashrc adds an assignment shell statement at the end of the Bash configuration file ~/.bashrc. The statement adds the new bin directory to the execution path which is held by the shell variable PATH.

Since the terminal program runs the commands in ~/.bashrc every time it is launched, the assigment shell statement will add the “new” bin directory to the execution path on every subsequent launch of the CloudShell terminal.

That means that the Scritps are not yet accessible through the execution path.

For the Script to become thus accessible, we need either to restart the CloudShell terminal, or to restart the CloudShell environment (the AWS instance mentioned earlier), or to run the source command to make the current CloudShell terminal run the commands in ~/.bashrc again, and thus get the PATH variable updated within this terminal session.

Let’s use the source command to test the Scripts are accessible through the execution path, and then look at how to restart the CloudShell terminal and the CloudShell environment.

Enter or copy-paste the following commands:

Code

csinstances_create.sh
source ~/.bashrc
csinstances_create.sh

The CloudShell terminal should now look like this:

.

The script csinstances_create.sh is one the Scripts installed in ~/.local/bincsaws. You can see in the screenshot that it was not found by the terminal before source was run to update the execution path, but thereafter it was found and run. As it requires a parameter (the name of a file), csinstances_create.sh only displayed the usage message and finished.

Your AWS CloudShell environment is now configured to use the Scripts in the next lesson: Managing AWS Instances.

Warning

Don’t delete the directory ~/_tmp_cloudspan_aws where the Scripts were downloaded

Please don’t delete that directory just yet. We will use some files there in the next lesson. Once we use those files you will delete that directory.

Restarting the CloudShell terminal and the CloudShell environment

You can restart the terminal by simply logging out of the terminal through entering the command exit or typing Ctrl-d (pressing the keys Ctrl and d simultaneously). Once you are logged out, press any key for the terminal to be launched again. Restarting the terminal is lightweight in that it is relatively quick because only the terminal program is restarted.

You can restart the CloudShell environment by closing the browser tab and launching CloudShell again, or by clicking on the Actions drop-down menu on the top right of the screen and then clicking on Restart.

.

Restarting the AWS CloudShell through that menu is heavyweight in that it will first stop and then relaunch the AWS Linux instance on which the AWS CloudShell terminal runs. It may be useful if you get stuck within a program and you don’t know how to get out (it happened to one of the authors).