Install cfn_nag on Windows

When writing any type of code you always want it to follow best practices or be as secure as it can be.

When writing AWS CloudFormation templates you can use cfn_nag to perform some basic security tests on your templates.

The tool can validate both JSON and YAML AWS CloudFormation templates against the AWS CloudFormation Resource Specification.

I recently wanted to use the cfn-nag tool on some templates I was writing but couldn't find any instructions to install on Windows, but I have found a way to do it.

Step 1 - Install Windows Subsystem for Linux

Windows has a tool called Windows Subsystem for Linux (WSL), that allows you to run a GNU/Linux environment on your Windows machine without the overhead of having to run a dual booting system on your machine.

To install WSL on your machine open up an elevated PowerShell command and type:

wsl --install

This will download the latest Linux kernel, and install a Linux distribution, by default this is Ubuntu.

Once WSL has been installed you will be asked to set up a username and password.  Follow best practices with this.  If you ever forget the password, you can reset it.

Step 2 - Install Ruby

The cfn-nag tool has a dependency on Ruby so we need to ensure that is installed.  We can do this by issuing the command within our WSL terminal:

sudo apt install ruby

Step 3 - Install the cfn-nag tool

Now you have all the dependencies installed you can install the tool itself.  To do that we use the following command:

sudo gem install cfn-nag

Start to use cfn-nag

Everything is now installed and ready for you to use!