Shutdown Experiment Pack

Tammy Butow
Principal SRE
Last Updated:
February 3, 2020
Categories:
Chaos Engineering
,

Description

This Gremlin Shutdown Experiment Pack shares how you can utilise the Gremlin Shutdown attack. Shutdown is available with your Gremlin account.

What’s Included

  • Ability to shutdown cloud infrastructure hosts & containers on AWS, Azure, GCP & more
  • Ability to shutdown containers running locally with Docker

What we’ll break

With Gremlin, you have the ability to shutdown any host or container wherever it may reside.

This pack includes 4 x 5 minute experiments:

  • Experiment 1: Shutdown a cloud infrastructure host using Gremlin
  • Experiment 2: Shutdown a cloud infrastructure Docker container using Gremlin
  • Experiment 3: Shutdown a Kubernetes pod using Gremlin
  • Experiment 4: Shutdown a local Docker container using Gremlin
  • Experiment 5: Shutdown a cloud infrastructure host using the Gremlin API

What you’ll need

Get ready to unleash chaos, get your credentials!

After you have created your Gremlin account (request a trial here) you will need to get your Gremlin daemon credentials.

Login to the Gremlin App using your Company name and sign-on credentials. These details were emailed to you when you signed up to start using Gremlin. Make a note of your Team ID and Secret.

Experiment 1: Shutdown a cloud infrastructure host using Gremlin

Step 1.0 - Installing the Gremlin Daemon and CLI

First, ssh into your server and add the Gremlin Debian repository:

BASH

echo "deb https://deb.gremlin.com/ release non-free" | sudo tee /etc/apt/sources.list.d/gremlin.list

Import the repo’s GPG key:

BASH

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

Then install the Gremlin daemon and CLI:

BASH

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

Step 1.1 - Register your server to the Gremlin control plane

Using your Gremlin login credentials (which were emailed to you when you created your account), log in to the Gremlin App. Open Settings and copy your Team ID and Secret.

SSH into your server:

BASH

ssh -i your-key.pem ubuntu@server-ip

Initialise Gremlin by running the following command and follow the prompts to enter your Gremlin Team ID and Secret

BASH

gremlin init

Now you’re ready to run attacks using Gremlin.

Step 1.2 - Run a Shutdown Attack Using Gremlin

First click Create Attack.

First choose your target by selecting the host you registered with Gremlin.

Select target

Next we will use the Gremlin App to create a Shutdown Attack. Choose the State Category and Select the Shutdown Attack. If you like, you can change the delay to 0 and turn reboot off to trigger an immediate full shutdown.

Select shutdown

Click Unleash Gremlin and the Gremlin Shutdown Attack will shutdown your host.

Experiment 2 - Shutdown a cloud infrastructure container using Gremlin

Step 2.0 - Install Docker

In this step, you’ll install Docker.

Add Docker’s official GPG key:

BASH

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

Use the following command to set up the stable repository.

BASH

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

Update the apt package index:

BASH

sudo apt-get update

Make sure you are about to install from the Docker repo instead of the default Ubuntu 16.04 repo:

BASH

apt-cache policy docker-ce

Install the latest version of Docker CE:

BASH

sudo apt-get install docker-ce

Docker should now be installed, the daemon started, and the process enabled to start on boot. Check that it’s running:

BASH

sudo systemctl status docker

Make sure you are in the Docker usergroup, replace $USER with your username:

BASH

sudo usermod -aG docker $USER

Log out and back in for your permissions to take effect, or type the following:

BASH

su - ${USER}

Step 2.1 - Create an htop container for monitoring

Htop is an interactive process viewer for UNIX. We’ll use it to monitor the progress of our attacks.

First create the Dockerfile for your htop container:

BASH

vim Dockerfile

Add the following to the Dockerfile:


FROM alpine:latestRUN apk add --update htop && rm -rf /var/cache/apk/*ENTRYPOINT ["htop"]

Build the Dockerfile and tag the image:

BASH

sudo docker build -t htop .

Run htop inside a container, this will monitor the host:

BASH

sudo docker run -it --rm --pid=host htop

To exit htop, enter q.

Next we will create an NGINX container and monitor it directly by joining the container’s pid namespace.

Step 2.2 - Create an NGINX container to attack

First we will create a directory for the html page we will serve using nginx:

BASH

mkdir -p ~/docker-nginx/html

BASH

cd ~/docker-nginx/html

Create a simple HTML page:

BASH

vim index.html

Paste in this content:


<html>    <head>        <title>Docker nginx tutorial</title>        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">    </head>    <body>        <div class="container">            <h1>Hello it is your container speaking</h1>            <p>This nginx page was created by your Docker container.</p>            <p>Now it’s time to create a Gremlin attack.</p>        </div>    </body></html>

Create a container using the nginx Docker image:

BASH

sudo docker run -l service=nginx --name docker-nginx -p 80:80 -d -v ~/docker-nginx/html:/usr/share/nginx/html nginx

Make sure the docker-nginx container is running:

BASH

sudo docker ps


CONTAINER ID        IMAGE               COMMAND                       CREATED                 STATUS                   PORTS                         NAMES352609a67e95        nginx               "nginx -g 'daemon of…"        33 seconds ago          Up 32 seconds       0.0.0.0:80->80/tcp              docker-nginx

Step 2.3 - Set up your Gremlin agent credentials

Using your Gremlin login credentials (which were emailed to you when you created your account), log in to the Gremlin App. Open Settings and copy your Team ID and Secret.

Set the following export variables:

BASH

export GREMLIN_TEAM_ID=your_team_id

BASH

export GREMLIN_TEAM_SECRET=your_team_secret

Step 2.4 - Run the Gremlin Daemon in a Container

Use docker run to pull the official Gremlin Docker image and run the Gremlin daemon:

BASH

sudo docker run -d \    --net=host \    --pid=host \    --cap-add=NET_ADMIN \    --cap-add=SYS_BOOT \    --cap-add=SYS_TIME \    --cap-add=KILL \    -e GREMLIN_TEAM_ID="${GREMLIN_TEAM_ID}" \    -e GREMLIN_TEAM_SECRET="${GREMLIN_TEAM_SECRET}" \    -v /var/run/docker.sock:/var/run/docker.sock \    -v /var/log/gremlin:/var/log/gremlin \    -v /var/lib/gremlin:/var/lib/gremlin \    gremlin/gremlin daemon

Make sure to pass in the three environment variables you set in Step 4. If you don’t, the Gremlin daemon cannot connect to the Gremlin backend.

Use docker ps to see all running Docker containers:

BASH

sudo docker ps


CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES7167cacb2536        gremlin/gremlin     "/entrypoint.sh daem…"   40 seconds ago      Up 39 seconds                            practical_benzfb58b77e5ef8        nginx               "nginx -g 'daemon of…"   10 minutes ago      Up 10 minutes       0.0.0.0:80->80/tcp   docker-nginx

Jump into your Gremlin container with an interactive shell (replace 7167cacb2536 with the real ID of your Gremlin container):

BASH

sudo docker exec -it 7167cacb2536 /bin/bash

From within the container, check out the available attack types:

BASH

gremlin help attack-container


Usage: gremlin attack-container CONTAINER TYPE [type-specific-options]Type "gremlin help attack-container TYPE" for more details:  blackhole # An attack which drops all matching network traffic  cpu   # An attack which consumes CPU resources  io    # An attack which consumes IO resources  latency # An attack which adds latency to all matching network traffic  memory  # An attack which consumes memory  packet_loss # An attack which introduces packet loss to all matching network traffic  shutdown  # An attack which forces the target to shutdown  dns   # An attack which blocks access to DNS servers  time_travel # An attack which changes the system time.  disk    # An attack which consumes disk resources  process_killer  # An attack which kills the specified process

Then exit the container.

Step 2.5 - Run a Shutdown Attack against the NGINX container from a Gremlin Container

In this step we will run gremlin attack-container to target the NGINX container by its ID and run a Shutdown Attack against it.

Before running the Shutdown attack, use htop to monitor the docker-nginx container (replace f291a040a6aa with your docker-nginx container ID):

BASH

sudo docker run -it --rm --pid=container:f291a040a6aa htop

You will see the following:


1  [                                                                           0.0%]   Tasks: 3, 0 thr; 1 running  2  [|                                                                          0.7%]   Load average: 0.72 0.41 0.21   Mem[|||||||||||||||||||||||||                                            141M/3.86G]   Uptime: 00:30:34  Swp[                                                                          0K/0K]  PID USER      PRI  NI  VIRT   RES   SHR S CPU% MEM%   TIME+  Command             47 root       20   0  4488  2236   932 R  0.0  0.1  0:00.07 htop    1 root       20   0 32428  5180  4504 S  0.0  0.1  0:00.03 nginx: master process nginx -g daemon off;    8 101        20   0 32900  2476  1448 S  0.0  0.1  0:00.00 nginx: worker process

Run the following to create the Shutdown container attack against the container (replace f291a040a6aa with your docker-nginx container ID):

BASH

sudo docker run -d -it \    --cap-add=NET_ADMIN \    -e GREMLIN_TEAM_ID="${GREMLIN_TEAM_ID}" \    -e GREMLIN_TEAM_CERTIFICATE_OR_FILE="${GREMLIN_TEAM_CERTIFICATE_OR_FILE}" \    -e GREMLIN_TEAM_PRIVATE_KEY_OR_FILE="${GREMLIN_TEAM_PRIVATE_KEY_OR_FILE}" \    -v /var/run/docker.sock:/var/run/docker.sock \    gremlin/gremlin attack-container f291a040a6aa shutdown

Experiment 3 - Shutdown a Kubernetes pod using Gremlin

Kubernetes is a container management system which is built with reliability in mind. Architecture is commonly 1 master and 2 or more nodes which are replicated from the master. When the master dies the nodes are ready to replace it. When one node dies another will be ready to replace it.

To create a Kubernetes cluster follow our guide on "How to Use and Install Kubernetes with Weave Net".

Step 3.0 - Retrieve Your Team ID and Secret Key

To install the Gremlin agent and Kubernetes agent, you will need your Gremlin Team ID and Secret Key. If you don’t know what your Team ID and Secret Key are, you can get them from the Gremlin web app.

Visit the Teams page in Gremlin, and then click on your team’s name in the list.

Gremlin Teams page

On the Teams screen click on Configuration.

Teams configuration screen

Make a note of your Team ID.

If you don’t know your Secret Key, you will need to reset it. Click the Reset button. You’ll get a popup reminding you that any running agents using the current Secret Key will need to be configured with the new key. Hit Continue.

Next you’ll see a popup screen that will show you the new Secret Key. Make a note of it.

Secret Key popup

Step 3.1 - Install the Gremlin Agent with Helm

The simplest way to install the Gremlin agent on your Kubernetes cluster is to use Helm. If you do not already have Helm installed, go here to get started. Once Helm is installed and configured, the next steps are to add the Gremlin repo and install the agent.

Add the Gremlin Helm chart:

BASH

helm repo add gremlin https://helm.gremlin.com

Create a namespace for the Gremlin Kubernetes agent:

BASH

kubectl create namespace gremlin

Next you will run the <span class="code-class-custom">helm</span> command to install the Gremlin agent. In this command there are three placeholder variables that you will need to replace with real data. Replace <span class="code-class-custom">$GREMLIN_TEAM_ID</span> with your Team ID from step1, and replace <span class="code-class-custom">$GREMLIN_TEAM_SECRET</span> with your Secret Key from step 1. Replace <span class="code-class-custom">$GREMLIN_CLUSTER_ID </span>with a name for the cluster.

If you are using Helm v3, run this command:

BASH

helm install gremlin gremlin/gremlin \
    --namespace gremlin \
    --set gremlin.secret.managed=true \
    --set gremlin.secret.type=secret \
    --set gremlin.secret.teamID=$GREMLIN_TEAM_ID \
    --set gremlin.secret.clusterID=$GREMLIN_CLUSTER_ID \
    --set gremlin.secret.teamSecret=$GREMLIN_TEAM_SECRET

For older versions of Helm, use the --name option:

BASH

helm install gremlin/gremlin \
    --name gremlin \
    --namespace gremlin \
    --set gremlin.secret.managed=true \
    --set gremlin.secret.type=secret \
    --set gremlin.secret.teamID=$GREMLIN_TEAM_ID \
    --set gremlin.secret.clusterID=$GREMLIN_CLUSTER_ID \
    --set gremlin.secret.teamSecret=$GREMLIN_TEAM_SECRET

If you’re not sure which version of Helm you’re using, run this command:

BASH

helm version

For more information on the Gremlin Helm chart, including more configuration options, check out the chart on Github.

Step 3.2 - Creating attacks using the Gremlin App

Example: Creating a Shutdown Attack against a Kubernetes node using the Gremlin App

You can use the Gremlin App or the Gremlin API to trigger Gremlin attacks. You can view the available range of Gremlin Attacks in Gremlin Help.

To create a Shutdown Attack click Attacks in the left Navigation bar and New Attack.

Host targeting should be selected by default. Click on the Exact button to expand the list of available hosts, and select one of them. You’ll see the Blast Radius for the attack is limited to 1 host.

Click “Choose a Gremlin,” and then select State and Shutdown.

Leave the Delay set to 1 minute. This is the delay before the attack begins. Leave the Reboot radio button set to On. This will start the host up again after the shutdown.

When your attack is finished it will move to Completed Attacks in the Gremlin App. To view the logs of the Attack, click on the Attack in Completed Attacks then click to the arrow to view the logs.

Experiment 4 - Shutdown a local Docker container using Gremlin

Step 4.0 - Install Docker For Mac

First you will need to install Docker For Mac if you do not yet have it on your local computer, follow the instructions provided by Docker.

Step 4.1 - Set up your Gremlin credentials

The Gremlin daemon (gremlind) connects to the Gremlin backend and waits for attack orders from you. When it receives attack orders, it uses the CLI (gremlin) to run the attack.

BASH

export GREMLIN_TEAM_ID=your_team_id

BASH

export GREMLIN_TEAM_SECRET=your_team_secret

Step 4.2 - Create a Gremlin Docker container

Use docker pull to pull the official Gremlin Docker image:

BASH

docker pull gremlin/gremlin

Step 4.3 - Create an NGINX container to attack

First we will create a directory for the html page we will serve using nginx:

BASH

mkdir -p ~/docker-nginx/html
cd ~/docker-nginx/html

Create a simple HTML page:

BASH

vim index.html

Paste in this content:


<html>    <head>        <title>Docker nginx tutorial</title>        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">    </head>    <body>        <div class="container">            <h1>Hello it is your container speaking</h1>            <p>This nginx page was created by your Docker container.</p>            <p>Now it’s time to create a Gremlin attack.</p>        </div>    </body></html>

Create a container using the nginx Docker image:

BASH

sudo docker run -l service=nginx --name docker-nginx -p 80:80 -d -v ~/docker-nginx/html:/usr/share/nginx/html nginx

Make sure the docker-nginx container is running:

BASH

sudo docker ps


CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES7167cacb2536        gremlin/gremlin     "/entrypoint.sh daem…"   40 seconds ago      Up 39 seconds                            practical_benzfb58b77e5ef8        nginx               "nginx -g 'daemon of…"   10 minutes ago      Up 10 minutes       0.0.0.0:80->80/tcp   docker-nginx

Step 4.4 - Run A Gremlin Shutdown Attack

Now use the Gremlin CLI (gremlin) to run a Shutdown attack from within a Gremlin container:

BASH

sudo docker run -i \    --cap-add=NET_ADMIN \    -e GREMLIN_TEAM_ID="${GREMLIN_TEAM_ID}" \    -e GREMLIN_TEAM_SECRET="${GREMLIN_TEAM_SECRET}" \    -v /var/run/docker.sock:/var/run/docker.sock \    gremlin/gremlin attack-container docker-nginx shutdown

This attack will shutdown your nginx container.

Experiment 5: Shutdown a cloud infrastructure host using the Gremlin API

It is also possible to run attacks programmatically using the Gremlin API. We will run these attacks from a Mac OS laptop.

Step 5.0 - Installing the Gremlin Daemon and CLI

First, ssh into your server and add the Gremlin Debian repository:

BASH

echo "deb https://deb.gremlin.com/ release non-free" | sudo tee /etc/apt/sources.list.d/gremlin.list

Import the repo’s GPG key:

BASH

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

Then install the Gremlin daemon and CLI:

BASH

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

Step 5.1 - Register your server to the Gremlin control plane

Using your Gremlin login credentials (which were emailed to you when you created your account), log in to the Gremlin App. Open Settings and copy your Team ID and Secret.

Initialise Gremlin by running the following command and follow the prompts to enter your Gremlin Team ID and Secret:

BASH

gremlin init

Now you’re ready to obtain your Gremlin API token.

Step 5.2 - Obtain your Gremlin API token

First access your Gremlin API token by providing your gremlin username and password to /users/auth, replacing your email, password and company name in the curl request below:

BASH

curl -X POST --header 'Content-Type: application/x-www-form-urlencoded' \    --data-urlencode 'email=name@youremail.com' \    --data-urlencode 'password=changeit' \    --data-urlencode 'companyName=changeit' \    'https://api.gremlin.com/v1/users/auth'

Your API token will be displayed on the screen. The example below shows "Bearer Y4MGE3MGMzOmdyZW1saW5AZ3JlbWxpbmluYy5jb206NWNhMWFiMWU" as the API token that will be used for interacting with the Gremlin API:


[  {   "expires_at": "2099-01-00T00:00:00.000Z",   "header": "Bearer Y4MGE3MGMzOmdyZW1saW5AZ3JlbWxpbmluYy5jb206NWNhMWFiMWU",   "identifier": "yourname@email.com",   "org_id": "e7352a6b-a9a0-513c-8000-980f680a70c3",   "org_name": "My Org (Production)",   "renew_token": "5ca1ab1e-ffff-0000ffff0001",   "role": "USER",   "token": "5ca1ab1e-ffff-0000ffff0000"  },]

Step 5.3 - Store your Gremlin API token

On your local computer (Mac OS), store your Gremlin API token as an environment variable:

BASH

curl --header "Content-Type: application/json" \    --header "Authorization: $bearertoken" \    https://api.gremlin.com/v1/attacks/new \    --data '    {        "command": { "type": "shutdown" },        "target": { "type": "Random" }    }'

Check to ensure you have set your token correctly:

BASH

echo $bearertoken

Your API token will be displayed on your terminal screen:


Bearer Y4MGE3MGMzOmdyZW1saW5AZ3JlbWxpbmluYy5jb206NWNhMWFiMWU

Now you’re ready to run attacks using the Gremlin API .

Step 5.4 - Run a Shutdown Attack Using The Gremlin API

Now you’re ready to run a shutdown attack using the Gremlin API . Run the following command on your local computer (Mac OS):

BASH

curl --header "Content-Type: application/json" \    --header "Authorization: $bearertoken" \    https://api.gremlin.com/v1/attacks/new \    --data '    {        "command": { "type": "shutdown" },        "target": { "type": "Random" }    }'

View the attack in progress using the Gremlin API:

BASH

curl -X GET "https://api.gremlin.com/v1/attacks/active" -H "Authorization: $bearertoken" -H "accept: application/json"

Your current attack will be displayed in terminal:


[  {    "target_type": "Host",    "targets": [      "docker-for-desktop"    ],    "org_id": "3f242793-018a-5ad5-8000-fb958f8dc084",    "args": [      "shutdown"    ],    "created_at": "2019-03-07T18:56:24.232Z",    "create_source": "Api",    "stage": "Pending",    "stage_lifecycle": "Active",    "guid": "b452e2a6-410a-11e9-95a4-0242cbd04b28",    "start_time": "2019-03-07T18:56:24.232Z",    "create_user": "youremail@email.com",    "updated_at": "2019-03-07T18:57:31.191Z",    "kind": "Api"  }

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