Yaml Parser with various additions.
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.



Build Status Test Coverage Dependabot Status Dependencies NPM Downloads Semantic-Release Gardener

Basic Yaml Loading with additional functionality, i.e. resolve file depedencies, resolve variables, deep merge hierachies.

Useful for loading improved serverless configuration. For yaml loading this package uses js-yaml.

Getting Started

$ npm install --save yaml-boost


const yaml = require('yaml-boost');


Matching yaml.dump() function is also available.

Variable and File Resolution

Works identical to how this is defined for serverless here.

Both yml and yaml file endings are supported.


Bake variables when loading files
${file(./path/to/file.yml), key1=value1&key2=value2}
Reference Packages

You can reference packages by using

Reference Js files

Reference js instead of yaml files.


The reference file needs to export simple object containing configuration

module.exports = {};
Reference Function inside Js file

Reference function inside js file.


The reference file needs to export simple function returning an object. Available variables are passed in.

module.exports = args => ({ args });
Relative File References

Once can reference files relative to the current file by using ^ as a prefix like so

Deep Merge

Analogue to the << yaml syntax we can use <<< to deep merge into the current nesting level. This is helpful when merging files into already existing hierarchies.


  - list entry one

  - data:
      - list entry two
  - other: things

results in

  - list entry one
  - list entry two
other: things

Serverless Example

Define serverless.js as

const path = require('path');
const minimist = require('minimist');
const yaml = require('yaml-boost');

module.exports = yaml.load(path.join(__dirname, 'serverless.core.yml'), minimist(process.argv.slice(2)));

Then instead of defining serverless.yml, define your config in serverless.core.yml.