1. TA Section 2017-4-1 Zhenyu Zhao
DevOps Engineer at HUIT Infrastructure Technology Services

2. Agenda
CloudFormation template anatomy: built-in functions, mappings, parameters
How to update a stack without deleting it
Demo Building a simple infrastructure from the scratch with VPC, subnet, route table, network ACL, security group, an EC2 instance with User Data
Q & A

3. How CloudFormation Works

4. How CloudFormation Change Set Works

5. JSON Components
Structurally, starts with an object and key-value pairs are building block and every item is represented by a string literal
{} represents an object (like a dictionary of key-value pairs)
[] represents an array (a list of string values)
The goal is to represent data structure relationship
Syntactically, JSON is straightforward. Semantically, it is up to JSON parser to interpreter the code. CloudFormation template uses JSON to structure the code

6. CloudFormatrion Boilerplate code
See code File: boilerplate

7. Built-in functions, Mappings and Parameters
Built-in Functions that we are using here:
Ref
Fn::FindInMap
Fn::Join
Fn::Select
Fn::GetAZs
Fn::Base64
Reference:
function-reference.html

8. Built-in functions, Mappings and Parameters
Multi-dimentional data structure
Analogous to Python dictionary data structure
Always use Fn::FindInMap to look up a key

9. Built-in functions, Mappings and Parameters
Dynamic and user-driven
Always use Ref to return pointer to a parameter

10. Demo We are building a simple infrastructure from the scratch: A VPC
A Internet gateway
A public subnet
A network ACL that is attached to the public subnet
A route table that is attached to the public subnet
A security group
An EC2 instance with User Data to set up Apache, MySQL, & PHP
zhen-ta-tempate5-base => zhen-ta-tempate5-update1 => zhen-ta-tempate5-update2 =>
zhen-ta-tempate5-update3 => zhen-ta-tempate5-update4 => zhen-ta-tempate5-update5 => zhen-ta-tempate5-update6

11. Q & A
When creating a new CloudFormation stack, how do you correctly reference existing resources (such as a VPC or subnet) in your script? (From Harry) Can you have two AWS resource of same type with same value for the Name tag? where are the files from section stored on the course site?

12. Q & A
Can we get this vlcid using Parameters?Like a dropdown Explore the parameter type in AWS documentation Zhen, if “ZhenVPC” was an existing VPC in my account, would I just delete the “ZhenVPC” section you have in “Resources”?