Serverless Framework Glob-Merge for YAML

This is a Serverless Framework plugin that lets you merge serverless.yml files using Serverless Framework variables from YAML. You write a variable that contains a path glob (i.e., **/serverless.yml) to merge YAML files and an optional subpath to select only the data you want from the merged YAML.

This plugin is primarily intended for splitting serverless.yml into smaller chunks without needing to create separate Serverless Framework projects or custom ${file(./script.js)} scripts.

Requirements

• Serverless Framework >= 1.52

Installation

• Install the package by typing npm i --save-dev serverless-glob-merge-yaml.
• Add serverless-glob-merge-yaml to your serverless.yml plugins section.
• Change your variable syntax to allow globs in variable references. (See the example below.)

Example serverless.yml

serverless.yml

service:
  name: test

plugins:
  - serverless-glob-merge-yaml

provider:
  name: aws
  runtime: nodejs12.x
  
  # Change the variable syntax to allow *, +, and | in the variables.
  variableSyntax: "\\${([ *+|~:a-zA-Z0-9._@\\'\",\\-\\/\\(\\)]+?)}"

  iamRoleStatements:
    # Look for serverless.yml in src/ and subdirectories and get the
    # iamRoleStatements from the merged YAML.
    ${glob-merge-yaml:src/**/serverless.yml:provider.iamRoleStatements}

  environment:
    # Provide defaults use stage overrides. The YAML is merged in
    # lexicographical order from env/
    ${glob-merge-yaml:env/*+(default|${opt:stage,'dev'}).yml}

    # The above works like this: Assume you have a files named
    #  env/0default.yml
    #  env/1dev.yml
    #  env/1prod.yml
    #
    # In the dev stage, YAML will merge in this order:
    #  1) env/0default.yml
    #  2) env/1dev.yml
    #
    # In the prod stage, YAML will merge in this order:
    #  1) env/0default.yml
    #  2) env/1prod.yml
    #
    # See: https://github.com/isaacs/node-glob#glob-primer

functions:
  # Merge all functions.yml in src/
  ${glob-merge-yaml:src/**/functions.yml}

resources:
  # Merge all resources.yml in src/
  ${glob-merge-yaml:src/**/resources.yml}

Variable Syntax

The syntax of the variable expression is broken down like this: ${glob-merge-yaml:PATH_GLOB:SUB_PATH}

• glob-merge-yaml - This is the plugin's variable prefix.
• PATH_GLOB - Replace this with a path glob. The glob syntax is based on the glob package
• SUB_PATH - This is an object path that can be used to traverse the merged data structure. You can omit the subpath to return the merged data structure.

Recursion

The YAML files merged with glob-merge-yaml can contain additional glob-merge-yaml statements, so be careful not to create circular references. :)

Contributing

Pull requests are welcome! Especially test scenarios for different situations and configurations.