eb-sqs-imdsv2

What Is It?

Running [this script][https://gist.github.com/ryuheechul/b2301f0ed9714b98bb410a567b683b2f/c543d4fba8502cc4acf8217140fa5a36d0fe3fbd) caused a service outage once.

Only after the outage, a better method was discovered

In case with CloudFormation

- Namespace: aws:autoscaling:launchconfiguration
  OptionName: DisableIMDSv1
  Value: "true"

or with CLI

aws ec2 modify-instance-metadata-options \
  --region "${region}" --instance-id "${instance_id}" \
  --http-token required \
  --http-endpoint enabled \
  --http-put-response-hop-limit 2 # important

The service was running via AWS Elastic Beanstalk depending on a AWS SQS queue.

The purpose of this repo is to reconstruct environment that can:

• provision an environment that simulate the outage (via --http-put-response-hop-limit 1)
• simulate DisableIMDSv1 working fine with
• Celery functionality with SQS

Prerequisites

Install Earthly and its pre-requisites

How to Run

make integration-test to test locally - using Redis for messaging instead of SQS in this case.

make deploy to deploy to AWS via CDK - using SQS for messaging but Redis is still being used as a result backend. I assume aws configure has been done on the host machine

make destroy to tear down.

cat Makefile to see the rest of things you can do.

Key Files

Build & Deploy

• Makefile - all you need to run things, it's a gateway and a manual
• Earthfile - all actual builds and triggers are written here
• ./gen-dc-integration-test.sh - generate docker-compose.it.yml for integration tests
• ./gen-dc-elasticbeanstalk.sh - generate docker-compose.yml and other files for Elasticbeanstalk
• docker-compose.cdk.yml - used to run cdk deployments
• cdk/eb-sqs-imdsv2/lib/eb-sqs-imdsv2-stack.ts - the meat of cdk deployments

Python

• requirements.txt - PYPI packages to install
• tasks.py - Celery tasks
• server.py - Flask server to handle requests that delegates to Celery

Tests

• deps.ts - Deno packages
• test.ts - Integration test code using Deno

What I Learned

Earthly Is a Fantastic Tool

It was my first opportunity to use Earthly. Prior to Earthly I always felt awkward use Makefile and Dockerfile together. Now we are talking with Earthfile and it makes the job a lot smoother. I highly recommend you giving it a go if you haven't already.

Logs on Elastic Beanstalk

I admit that I didn't even know there is such a thing in Elastic Beanstalk. I don't find EB exactly a user friendly platform. When Events didn't have much information I debugged things in the dark until I discovered this menu. This is a must.

EB > Logs > Request Logs > Last 100 Lines (or Full Logs) It will show you the missing information (such as docker engine logs) from Event page.

Arm Version With Graviton Processors

Initially I naively built the image with this BUILD --platform=linux/arm/v7 --platform=linux/amd64 +push (yes, I blinly copy-pasted from https://docs.earthly.dev/docs/guides/multi-platform)

And this is the error I've got:

ERROR: for server  no matching manifest for linux/arm64/v8 in the manifest list entries

ERROR: for worker  no matching manifest for linux/arm64/v8 in the manifest list entries
no matching manifest for linux/arm64/v8 in the manifest list entries

So I changed to BUILD --platform=linux/arm64 --platform=linux/amd64 +push and it all worked fine after.

Trailing comma make the values to be tuple on Python

region = environ['REGION'],

expected it to be "ca-central-1" (because I didn't notice , at the end of the line) but it actually became ("ca-central-1,)

So if you are copying lines from a JSON-looking dictionary, make sure to delete the trailing comma

Deno Can Be Good Choice for a Quick and Simple Integration Test

Because it has a built-in testing framework and fetch API is available from the standard module. This gets rid of the needs of having to choose and set up third party framework/library options like a case of working with NodeJS.