12 Weeks AWS Workshop Challenge

Week Six: Infrastructure-as-Code

AWS CloudFormation icon

Introduction to AWS CloudFormation

AWS CloudFormation is an IaaS (Infrastructure-as-a-Service) service, that allows you to design and deploy your infrastructure as either YAML or JSON code.

The benefits of provisioning your infrastructure as code is that you get to easily replicate your infrastructure quickly across regions. The ease of replicability is an automation process, which reduces human error, and enhances efficiency and consistency in your code across regions.

CloudFormation has two main components: Stacks & Templates. With templates, you can provision various resources such as EC2 Instances and S3 Buckets, amongst others, and with stacks, you can manage your infrastructure and view multiple. A stack is a collection of templates and other stacks, which means that it can consist of one or more templates which are easy to create, delete, update or rollback.

CloudFormation is free to use, you will be charged for the resources you provision.

Components of CloudFormation Templates

AWS Template Version: The format version is the first line you’ll see when working with a CloudFormation template. The current version is 2010–09–09.

Description (Optional): You can use the Description section to provide meaning about the purpose of the template.

Metadata (Optional): You can use the Metadata section to provide more information about your template.

Parameters (Optional): You can use Parameters to set inputs and and pass default values during creation.

Mappings (Optional): You can use Mappings to map (point) values based in different regions.

Conditions (Optional): You can use Conditions to specify what your template should do based on a particular value.

Resources (Required): Resources are mandatory. You should define at least one resource that needs to be provisioned.

Outputs (Optional): You can use the Outputs section to declare values that you can import to other stacks. As a best practice, and for security reasons, you should not include any sensitive information in the Outputs section.

Creating an AWS CloudFormation Template

Do you have an AWS CloudFormation template?

Yes? Well, that’s cool. See you in my next post then.

No? Ok, no big deal. Let’s provision some resources using a simple Sample Template on AWS CloudFormation.

Prerequisites

To create an AWS CloudFormation Template you will need:

(1) an AWS account to configure the resources.

(2) basic understanding of YAML (or just an ability to read YAML, it’s designed to be human readable and straightforward).

(3) an existing EC2 KeyPair.

Step by Step Guide

How to Create an AWS CloudFormation Template (via the Management Console)

1. Login to the AWS Management Console using your IAM user name.
2. We will be using the US East (N. Virginia) (us-east-1) region. So, on the top right navigation bar, make sure N. Virginia is selected.
3. On the top left corner, click on the Services button.
4. Select Management & Governance on the left side of the drop down menu.
5. Select CloudFormation.
6. Click on Stacks on the left side of your screen.
7. Click the Create Stack button.
8. Pre-requisite — Prepare template: Use sample template.
9. Select a sample template. Sample templates: Simple LAMP stack.
10. Click Next.
11. Stack name: MyStack.
12. DBName: MyDatabase.
13. DBPassword: MyPassword.
14. DBRootPassword: MyPassword.
15. DBUser: MyUser.
16. InstanceType: t2.micro.
17. KeyName: select an existing KeyPair in the N. Virginia region.
18. SSHLocation: 0.0.0.0/0
19. Click Next.
20. Configure Stack options: Leave everything as default.
21. Click Next.
22. Review my stack: click Submit.
23. Status: CREATE_IN_PROGRESS,
24. Wait for: CREATE_COMPLETE.
25. Click on Stack Info: This section shows you the StackID, Description, the Status of your stack, Creation time and whether or not Termination Protection is activated or deactivated.
26. To enable Termination Protection you can click on Stack Actions.
27. Select Edit Termination Protection.
28. Edit termination protection for MyStack? Make sure the Deactivated radio button is selected.
29. Click Save. In the Stack Info page, you can also view Tags, Stack Policy, Rollback Configurations, and Notification options. In our case, there is none.
30. Click on Events: This section shows you time, and status of the resources you’re provisioning
31. Click on Resources: This section shows the resources provisioned by your stack. In this case, it should be a WebServerInstance and WebServerSecurityGroup.
32. Click on Outputs: This section shows you the URL for your stack.
33. Click on the URL link.
34. You should see: Welcome to the AWS CloudFormation PHP Sample page.
35. Navigate back to your AWS CloudFormation page.
36. Click on Parameters: This section shows you the URL for your stack.
37. Click on Template: This section shows you what your template looks like.
38. Click View in Designer.
39. Select YAML, and analyze the template.
40. Click Components for a simpler view.
41. Click Parameters to view all the Parameters.
42. Click Mappings to view the Mappings.
43. Click Conditions. There are no Conditions in this template.
44. Click Metadata. There is no Metadata.
45. Click Outputs. Analyze the structure.
46. Click Close.

Resources Provisioned by Sample AWS CloudFormation Template

1. On the top left corner, click on the Services button.
2. Select Compute on the left side of the drop down menu.
3. Select EC2.
4. On the EC2 Instances dashboard, you should see the Instance and Security Group provisioned by your AWS CloudFormation Template.
5. Click Instances (running).
6. Click on the InstanceID.
7. Public IPv4 address: Click open address or copy and paste the Public IPv4 address in your browser.
8. You should see: Welcome to the AWS CloudFormation PHP Sample page. (If you don’t see the page, make sure you URL starts with HTTP and not HTTPS, because the Security Group allows HTTP Traffic on Port 80)
9. On the left side of your screen, under Network & Security, select Security Groups.
10. Click on the Security group provisioned by your Template.
11. Observe the Inbound rules HTTP (80) & SSH (22). Which means that you can privately access the instance through SSH and also access it publicly through HTTP.

Important: Clean Up Resources

Don’t get a Bill Shock by leaving unnecessary resources running.

1. Navigate back to CloudFormation.
2. Select myStack.
3. Click Delete.
4. Confirm Deletion by clicking Delete.
5. Status: DELETE_IN_PROGRESS
6. Click refresh. Your stack, and all the resources provisioned will be deleted.

End of Step by Step Guide

Conclusion

Congratulations! In this Step by Step Guide, you created a sample AWS CloudFormation Template, and launched an EC2 Instance and Security Group using the Template.

…And theoretically, you touched upon the basic concepts of an AWS CloudFormation template. The more you work with AWS CloudFormation Templates and Stacks, you will eventually configure more robust templates and stacks that can be launched in multiple Availability Zones & Regions.

Blog Post Summary

Theory

Introduction to AWS CloudFormation.

Practical

Launching resources using a sample AWS CloudFormation Template.