YAML-Blaster - Framework for processing YAML templates

This was created to ease the pain of having to use a giant single-file AWS Cloudformation template by allowing variable replacement, file loading, and loops.

Table of Contents

- Installation
- Usage
- CLI
- Features
- Simple Variable replacement
- Load a file
- Using top-level data scope
- Using specific data scope
- Loops

Installation

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``
$ npm install -g yaml-blaster
`

Usage

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Assuming your project looks like this
`
project
|
+-- template.yaml
|
+-- data.yaml
`
From the project directory just run
`
$ yaml-blaster \
-i template.yaml \ # The input template
-d data.yaml # A configuration file
`
Or from anywwhere run
`
$ yaml-blaster \
-i /full/path/to/project/template.yaml \
-d /full/path/to/project/data.yaml
`
To save the output to a file
`
$ yaml-blaster \
-i template.yaml \
-d data.yaml \
-o processed.yaml
`

Features

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Syntax: {{variable}} - Replace variables in the template

template.yaml
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
MyS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: {{name}}
`
data.yaml
`
name: my-bucket-name
`
run
`
$ yaml-blaster \
-i template.yaml \
-d data.yaml
`
output
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
MyS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: my-bucket-name
`


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Syntax: {{file:relative/path}} - load a file and replace it in the template

#### Using top-level data scope
By default, any variables in the loaded snippet
will be replaced using the top-level scope of the data file.

project structure
`
project
|
+-- template.yaml
|
+-- data.yaml
|
+-- snippets
|
+-- bucket.yaml
`
template.yaml
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
{{file:sub-templates/bucket.yaml}}
`
snippets/bucket.yaml
`
{{logicalName}}:
Type: AWS::S3::Bucket
Properties:
BucketName: {{bucketName}}
`
data.yaml
`
logicalName: MyS3Bucket
bucketName: my-s3-bucket
`
output
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
MyS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName:my-s3-bucket
`

#### Using specific data scope
Syntax: {{path.to.value, file:relative/path}} - load a file and replace variables under a specific scope

project structure
`
project
|
+-- template.yaml
|
+-- data.yaml
|
+-- snippets
|
+-- bucket.yaml
`
template.yaml
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
{{bucket1, file:sub-templates/bucket.yaml}}
{{bucket2, file:sub-templates/bucket.yaml}}
`
snippets/bucket.yaml
`
{{logicalName}}:
Type: AWS::S3::Bucket
Properties:
BucketName: {{bucketName}}
`
data.yaml
`
bucket1:
logicalName: MyFirstS3Bucket
bucketName: my-s3-bucket-1
bucket2:
logicalName: MySecondS3Bucket
bucketName: my-s3-bucket-2
`
output
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
MyFirstS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: my-s3-bucket-1
MySecondS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: my-s3-bucket-2
`


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Syntax: {{for:path.to.array, file:relative/path}} - add n number of instances of a snippet by referring to an array in the data file

project structure
`
project
|
+-- template.yaml
|
+-- data.yaml
|
+-- snippets
|
+-- bucket.yaml
`
template.yaml
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
{{for:buckets, file:sub-templates/bucket.yaml}}
`
snippets/bucket.yaml
`
{{logicalName}}:
Type: AWS::S3::Bucket
Properties:
BucketName: {{bucketName}}
`
data.yaml
`
buckets:
- logicalName: MyFirstS3Bucket
bucketName: my-s3-bucket-1
- logicalName: MySecondS3Bucket
bucketName: my-s3-bucket-2
`
output
`
AWSTemplateFormatVersion: '2010-09-09'
Resources:
MyFirstS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: my-s3-bucket-1
MySecondS3Bucket:
Type: AWS::S3::Bucket
Properties:
BucketName: my-s3-bucket-2
``