cloudformation-yml-merger

The merger to merge the multiple template files for the AWS Cloudformation into one template file.

• Automatically merge all the Cloudformation template yml files into one big yml file.
• The AWSTemplateFormatVersion will be located at the beginning of the generated yml file.
• For SAM(Serverless Application Model), the Transform will follow the AWSTemplateFormatVersion if the Transform exist.
• The blank lines will be trimed automatically.
• All yml comments will be removed

How the yml files to be merged.

Let's assume a folder A contains multiple yaml files as below:

A  
|- a.yaml
|- B - b.yaml
|- C - c.yml

# a.yaml
AWSTemplateFormatVersion: 
  '2010-09-09'
Transform: AWS::Serverless-2016-10-31

# b.yaml
Description:
  "description"
  
Outputs:
  Test:
    value: "sample value"

Resources:  
  SampleBucket: #S3 
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: PublicRead

# c.yml
Resources:
  APIGLambdaFunction: #Lambda 
    Type: AWS::Serverless::Function
    Properties:
      Handler: sample/sample.handler

The merge results would be as follows. All the comments and blank lines will be deleted and all the resources will be located in one Resources property.

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Resources:
  SampleBucket: 
    Type: 'AWS::S3::Bucket'
    Properties:
      AccessControl: PublicRead  
  APIGLambdaFunction:
    Type: 'AWS::Serverless::Function'
    Properties:
      Handler: sample/sample.handler
Description: description
Outputs:
  Test:
    value: sample value

How to install

$ npm install --save cloudformation-yml-merger

How to use

const merge = require('cloudformation-yml-merger').default;

...

try {
  merge(absolute-path-to-folder-containing-yml-files, absolute-path-target-yml-file);
} catch (err) {
  console.log('failed to merge the yml files', err);
}