Rotate your credentials and don’t forget MFA

by Gernot Glawe 14.03.2020 in aws security, iam, level-300, well-architected

According to the Well-Architected Framework and the least privileges principle, you should change your access keys and login password regularly. Therefore the user should have the right to edit their credentials. But only their own. Also using MFA - multi-factor authentication enhances the security even more. Therefore the user should be able to change MFA. But only their own. But how to do that? You have to combine two parts of AWS documentation. We will show you how you provide a “self-editing” group for your users with the CDK.

Building a Fargate-based container app with Cognito Authentication

by Maurice Borgmeier 11.03.2020 in aws level-400, fargate, cognito, alb, cdk, python

In this post I’m going to show you how to use Cognito User Authentication in combination with a Docker app running in Fargate behind an Application Load Balancer and we’re going to build all this with the Cloud Development Kit (CDK).

Why would you want to use this? You’re running your web application inside a docker container and don’t want to deal with user authentication.

The declarative vs imperative Infrastructure as Code discussion is flawed

by Gernot Glawe 23.02.2020 in aws cdk, terraform, iac

“Infrastructure definition has to be declarative”. Let’s see where this presumption gets us. My guess why some ops guys prefer pure terraform or CloudFormation is that these languages seem to be easier to understand. There is precisely one way of creating a specific resource in the language. If you use a programming language, there are many ways to solve one specific problem. The problem which could occur later in the project is that both declarative languages have boundaries in what they can do, with a programming language you do not have these boundaries.

The case of the missing bucket notifications

by Maurice Borgmeier 10.02.2020 in aws s3, sns, lambda, kms

The case of the missing bucket notifications A few days ago I was trying to do something quite simple. I wanted to send S3 Put-Events to multiple Lambda functions for processing. This is a pretty common pattern. To implement it you have to use an architecture such as the one you can see in the title image above. This is because S3 has a limit on the event handlers (notification targets) per event type of exactly one.

Three hurdles to skip before using the secure Instance Metadata Service V2

by Gernot Glawe 15.01.2020 in aws security, iam, ec2

Do not use new Instance Metadata Service V2 (imdsv2) without proper prevention!

You may think you can use Instance Metadata Service V2 right away, but there are a few caveats: Many old modules do not work with imdsv2 yet. We look at aws cli, the Systems Manager agent and the Instance Connect service. Currently, these services will not work with imdsv2 on an EC2 instance with the latest Amazon Linux 2 image out of the box. Here you can read how to make them work!