Mocking Terraform AWS using Docker

Terraform is a good tool for infrastructure provisioning.  However to test terraform it could be pretty difficult. So you will create some terraform scripts and upload to the cloud a run some slow Jenkins job? and if your syntax is wrong? Well, this process can be very painful. So I want to share some simple sandbox I built in order to speed up terraform + aws development in your local machine. I might be wondering how is that possible─? Well, my secret sauce is Localstack. So we are limited to all endpoints that localstack mocks. As Localsttack adds more endpoints we benefit from that. The main idea behind this simple project is to show how easy is to docker-ize somDevOpsps tools and make engineering easy.  Currently is very often to spend 40mim or more doing baking and that's is wrong. So that's kind of mainframe era so the idea is to save time and run things local - as much as possible. Docker helps a lot with that. I run software in production using AWS Amazon Linux. Now there is Amazon Linux docker image.  This is great because you can have some OS local as you will have it in PROD.



Getting Started

First of all, you need to have Docker and git installed. Them you can clone Terraform-Docker. Once you clone docker-terraform you can run bake command. That's needed just 1 time.  After baking the docker images we can run localstack(this will need to be in another terminal). After running Localstack we can run terraform-docker.

The Terraform Project

Under the src directory you will see:

  • main.tf:        Which is our terraform "code"
  • outputs.tf:     Which are all the things Terraform will output when it finishes.
  • variables.tf:  Which are custom variables and parameters we use for terraform.
For this sample, I will create a bucket on S3 using terraform. There are some special changes that need to be made in order to this work locally. For instance, we need to point to Localstack endpoints instead of AWS ones. 


So this file is where you can see a specific IP for the S3 endpoint. I can do this because I created a Docker Network which allows me to control and define IP address for docker networks. You can see how I create a docker network and attach IPs here.

The Dockerfile

Dockerfile is pretty simple. We are using the latest Amazon Linux as base Docker image and we are installing terraform 0.11.7 and we are copying local terraform project. There is a run.sh which pretty much does terraform init and terraform apply in order to run terraform as soon as you start this container.



That's it! Now we mocked Terraform and are running all in the local machine. You can get a full project with all source code and scripts here.

Cheers,
Diego Pacheco

Popular posts from this blog

C Unit Testing with Check

Image
When I start on IT, several years ago(+15), C was the first language that I learned. But was not the first language I mastered and deployed in production which was...surprisingly Visual Basic 6.0. However, when I learned C or any language back on that old and arcane time noddy was into testing. However now is impossible to work professionally in any language without tests. C is a low-level language but still kicks ass and has several interesting libs/frameworks. People use to fear C a lot because of lack of syntactical sugar but once you get used to it is not that hard at all. Today I want to show how you can do Unit Testing with C. I will not show how to do Unit Testing with C++ but with C ANSI actually. We will be using Check a unit test lib for C ANSI.
read more »

Having fun with Zig Language

Image
Zig is a general-purpose language created in 2016 by Andrew Kelly .  Zig aims to fix the issues C language has while being pragmatic and simple at the same time. Zig really shines as being simple by not having any hidden control flows, not having hidden memory allocations, no pre-processors, and no macros. Basically, it's one language and one language only. Since pre-processors and macros can get really complex and become their own universe. Sure it's not the Zig Philosophy.  Zig Compiler(Zig cc) also is a C compiler, and the interoperability from C to Zig is very good. Clearly, we can see influence from other languages like Go and Rust; however, Zig is pretty unique and different from Go and Rust.  Zig is fast. Zig is perfect for system programming. I bet we will see a lot of solutions being built in Zig. As a languages aficionado, I like to learn at least one language per year and sometimes more; Zig was my 2021 pick, did not regret it. Even if you dont use all languages in p
Keep reading

HMAC in Java

Image
In 2018 AWS CTO(Vogels) said : "Security is everyone's job". For the last 2 years, there was so many famous and big data leaks and breaks that made that statement be very true more than ever. Security often could mean worst performance and worst user experience so in order to get it right you really need to think about the designs before jumping into to code and consider performance and user experience has main requirements.  I was thinking about writing about how to do HMAC in Java for a while and recently Redis 6.0.0 come out and to my surprise, there was a refactoring on the password part in order to use HMAC.  Security easily could scare engineers often because it is not something well spread yet but I believe this will change soon. It does not matter if you have to deal with PII Data or not, security is super relevant because everybody is running their workloads at the cloud or with IoT and Edge devices which means more distribution, more code, more points of fail
read more »