Cloud Formation – Main Menu

February 18, 2018 Amazon Web Services (AWS), CloudFormation

Main Menu

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sudo apt-get update
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A declarative way of outlining your aWS Infrastructure for any resource
Example, “I need”
- A Security Group
- 2 EC2 Instances
- 2 Elastic IPs for the instances
- An S3 bucket
- An ELB
CloudFormation creates these for you, in the right order, with the exact configuration that you specify

Infrastructure as code
- No manually created resources, great for control
- Code can be version controlled using GIT
- Changes are reviewed through code
Cost
- Each resources with the stack are tagged with an identifier to easily see how much a stack costs
- You can estimate the cost of your resources using the template
- Savings: In Dev, you can automate deletion of a stack at 5:00pm and recreate safely at 8:00am
Productivity
- Re-create and destroy infrastructure on the fly
- Automatic Diagram generation (What??? How Cool!)
- Declarative programming
Separation of concern
- VPC stacks
- Network stacks
- App stacks
Don’t reinvent the wheel
- Leverage existing templates
  - Tweak as required
- Leverage the documentation

Adding a new Stack
- CloudFormation > [Create a new stack]
  - Upload File
  - Name Stack (Introduction)
    - Stack names cannot be edited after creation!
  - Add tags
    - awe:cloudformation:logical-id
    - aws:cloudformation:stack-id
    - aws:cloudformation:stack-name
  - [Create]
  - CloudFormation will provision items in the correct order. You do not have to plan this out.
Changing an Existing Stack
- Upload the file
- Edit tags
- Preview will show you the changes
  - Existing EC2 Instances that have been modified will be deleted and replaced.
Delete a Stack
- CloudFormation > Select Stack > Actions > Delete Stack
- This will delete the entire stack (all services created with the script) in the correct order.

Templates are uploaded in S3 and then referenced in CloudFormation
You cannot edit previous templates. You must re-upload a new version.
- AWS will determine what changes, does not change, needs to be added or deleted, etc., and in the correct order.
Stacks are identified by name, so use unique names
Deleting a stack deletes every single artifact that was created by CloudFormation.

Which of the following is a benefit of using CloudFormation
- Infrastructure as Code
- Cost
- Productivity
- Separation of Concerns
- Don’t reinvent the wheel
- All of the above
When we delete a CloudFormation stack, we have to delete everything that was created by it manually.
- Yes
- No
Stacks must have unique names
- Yes
- No
- * All stacks are identified by name, per Region