AWS CloudFormation Macros Custom processing on CloudFormation templates @ AWS UserGroup Meetup 01.11.2018

1. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
AWS CloudFormation Macros
Custom processing on CloudFormation templates
code examples: https://github.com/mnwk/cloudformation-macro-example
contact: xing.to/mnwk
mail@maiknowak.de

2. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 2
Maik Nowak - IT-Freelancer
Serverless IoT platform
Tech stack:
TypeScript
CloudFormation
Gitlab-CI
AWS:
...

3. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
CloudFormation and Macros
3
describe and provision infrastructure resourcesCFN template:
IaC and automation
JSON or YAML
CFN macro: preprocessor for CFN templates
transformation of template fragments

4. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
macros?
4
# aws cloudformation deploy
?

5. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
macros?
5
fragment
local, CI, ... CloudFormation macro
# aws cloudformation deploy
template process each macro
processed fragment transform fragment
validation validation of the template
macros are processed before changeset
creation
CFN console: “processed template”
create
changeset
update
stack
preprocessing
execution

6. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 6
Resources:
MyBucket:
Type: AWS::S3::Bucket
Properties:
BucketName: MyBucket
'Fn::Transform':
Name: 'MyMacro'
local macros - Fn::Transform global macros - Transform section
Transform: 'MyMacro'
Resources:
MyBucket:
Type: AWS::S3::Bucket
Properties:
BucketName: MyBucket
use macros | scope | parameter

7. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 7
Resources:
MyBucket:
Type: AWS::S3::Bucket
MyApi:
'Fn::Transform':
Name: 'MyMacro'
Type: AWS::ApiGateway::RestApi
Properties:
...
MyFunction:
Type: AWS::Lambda::Function
Resources:
MyBucket:
Type: AWS::S3::Bucket
'Fn::Transform':
Name: 'MyMacro'
MyApi:
Type: AWS::ApiGateway::RestApi
Properties:
...
MyFunction:
Type: AWS::Lambda::Function
Fn::Transform:
=> process all sibling elements
use macros | scope | parameter

8. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 8
Transform section:
=> process the
whole template
Transform: 'MyMacro'
Parameters:
...
Resources:
MyBucket:
Type: AWS::S3::Bucket
MyApi:
Type: AWS::ApiGateway::RestApi
...
Outputs:
use macros | scope | parameter

9. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 9
Transform section:Transform: 'MyMacro'
...
'Fn::Transform':
Name: 'MyMacro'
Parameters:
one: 'bar'
two: 23
three: false
string, number, boolean
unprocessed / not evaluated
Fn:Transform:
not possible
use macros | scope | parameter

10. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
AWS provided Macros | AWS::Include | AWS::Serverless
10
maintained by AWS
globally available

11. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
AWS provided Macros | AWS::Include | AWS::Serverless
11
Type: AWS::ApiGateway::RestApi
Properties:
Body:
'Fn::Transform':
Name: 'AWS::Include'
Parameters:
Location: s3://mybucket/swagger.yaml
Type: AWS::ApiGateway::RestApi
Properties:
Body:
swagger: '2.0'
host: 'example.org:80'
paths:
'/entity':
...
processed:
replace with
file content

12. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 12
Transform: AWS::Serverless-2016-10-31
Resources:
MyApi:
Type: AWS::Serverless::Api
Properties:
StageName: prod
...
Resources:
MyApi:
Type: AWS::ApiGateway::RestApi
Properties:
Body:
swagger: '2.0'
...
MyApiStage:
Type: AWS::ApiGateway::Stage
...
MyApiDeployment:
Type: AWS::ApiGateway::Deployment
processed
Serverless Application Model
- API
- Function
- SimpleTable
AWS provided Macros | AWS::Include | AWS::Serverless

13. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
custom macros
13
announced September 2018
AWS::CloudFormation::Macro
custom processing on CFN templates
AWS Lambda powered transformations
Usecases:
- simple converting / validation
- creation of complete substacks

14. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
limitations
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only in regions where AWS Lambda is available
all AWS Lambda limits apply here as well
resulting fragment must be valid JSON
processed template must pass create & update Stack validation
max. template size is calculated after macro processing
no macros in substacks
no use of macros within macros
intrinsic functions are evaluated after macro processing
same account

15. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
basic example: logging
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log template fragment in CloudWatch

16. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 16
basic example: logging
create macro | use macro | demo
export function handler(event, context, callback){
console.log(event)
callback(null, {
requestId: event.requestId,
status: 'success',
fragment: event.fragment
})
}
Lambda function
index.ts
LoggingFunction:
Type: AWS::Serverless::Function
Properties:
CodeUri: index.handler
...
LoggingMacro:
Type: AWS::CloudFormation::Macro
Properties:
Name: 'MyLoggingMacro'
FunctionName: !GetAtt LoggingFunction.Arn
CloudFormation stack
template.yaml

17. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 17
create macro | use macro | demo
Transform: 'MyLoggingMacro'
Resources:
MyBucket:
Type: AWS::S3::Bucket
Properties:
BucketName: 'cfn-test-mybucket'
'Fn::Transform':
Name: 'MyLoggingMacro'
Parameters:
one: 'bar'
two: 23
three: false
CloudFormation stack
using-template.yaml
basic example: logging

18. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 18
create macro | use macro | demo
-> demo <-
basic example: logging

19. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
advanced example: monitoring
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4 x CloudWatch::Alarm4 x Lambda 4 x Lambda
4 x CloudWatch::Alarm
Notification
> 70%
Timeout setting
template macro processed template

20. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
4 x Lambda
advanced example: monitoring substack
20
template macro
4 x CloudWatch::Alarm4 x Lambda
Notification
> 70%
Timeout setting
1 x CloudFormation::Stack
processed template

21. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de
advanced example: monitoring substack
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Stacks
??
??

22. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 22
conclusion

23. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 23
How would you use
macros?

24. 2018-11-01 AWS CloudFormation Macros @ AWS UG HH - mail@maiknowak.de 24
Thank you for your
attention.
xing.to/mnwk
mail@maiknowak.de