How to Install and Use Gremlin on Google Compute Engine with Ubuntu 16.04

Ana M Medina

Sr. Chaos Engineer

Last Updated: November 7, 2018

Categories: Chaos Engineering

Introduction

Gremlin’s “Failure as a Service” makes it easy to find weaknesses in your system before they cause problems for your customers. Gremlin is a simple, safe and secure way to use Chaos Engineering to improve system resilience. This tutorial will provide a walkthrough of the following:

• How to setup an instance using GCE
• How to install Gremlin on the instance
• How to create a CPU Attack using the Gremlin Control Panel

Prerequisites Before you begin this tutorial, you’ll need the following:

• A Google account for Google Cloud access
• A Gremlin account (sign up here)

Step 1 - Create new Instance using GCE

In this step, you’ll use GCE to setup a new instance to use with Gremlin. Google Compute Engine (GCE) lets you use virtual machines that run on Google's infrastructure.

First, log in to Google Cloud Console and proceed to Compute Engine, create a project to continue. Now let’s create the instance we need, name it as you please and use the region that is closest to you. For Machine Type, we’ve selected 4 vCPUS / 15 GB Memory and for Boot disk select the ‘Ubuntu 16.04 LTS’ image with standard persistent disk of 10GB.

After this, press the ‘Create’ button to create the instance.

Step 2 - Connect to your instance using GCE tools

While on the 'VM Instances' tab, find the instance you’ve just created, click the SSH button and a pop-up window will open. We are now connected to the server you’ve created and can now install Gremlin!

Step 3 - Installing Gremlin

In this step, you'll install Gremlin

First, ssh into your host and add the gremlin repo:

1ssh username@your_server_ip
2
3echo "deb https://deb.gremlin.com/ release non-free" | sudo tee /etc/apt/sources.list.d/gremlin.list

Import the GPG key:

1sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C81FC2F43A48B25808F9583BDFF170F324D41134 9CDB294B29A5B1E2E00C24C022E8EF3461A50EF6

Then install the Gremlin agent:

1sudo apt-get update && sudo apt-get install -y gremlin gremlind

After you have created your Gremlin account (sign up here) you will need to find your Gremlin Daemon credentials. Login to the Gremlin App using your Company name and sign-on credentials. These were emailed to you when you signed up to start using Gremlin.

Navigate to Team Settings and click on your Team. Make a note of your Gremlin Secret and Gremlin Team ID.

Then initialise Gremlin and follow the prompts:

1gremlin init

You are now ready to create attacks using the Gremlin App.

Step 4 - Run a CPU Attack

We are going to use the Gremlin Control Panel to run a CPU Attack, you can also use the API or the CLI to do so. There are various attacks of attacks you can run using Gremlin, check out the list here. The CPU attack is the ‘Hello World’ of Chaos Engineering, it generates high load for one or more CPU cores. For “Choose the Targets”, we will select ‘Host’ and use 10.142.0.2.

We now have to Choose a Gremlin, the CPU attack is found under the “Resource” Gremlins. I’ve filled out the form for the attack to run on one core for 60 seconds.

Make sure to press the green ‘Unleash Gremlin’ button to unleash your first gremlin! While your attack is running you can run this command to see the gremlin attack in action:

1top

On the top, these processes displayed:

18160 gremlin   20   0   37736   9856   6180 S  99.7  0.1   0:16.30 gremlin
22682 gremlin   20   0   44720  11936   5632 S   0.7  0.1   0:16.68 gremlind

Conclusion

You've now set up an instance using GCE, installed Gremlin and unleashed your first Gremlin. Feel free to explore around using the other gremlins, you can learn about the full range of gremlins available at Gremlin Attacks.