Parse AWS SAM YAML Templates & Validate JSON Schema

sam-validate.rb

#!/usr/bin/env ruby

require 'pp'
require 'json'
require 'yaml'
require 'open-uri'
require 'json-schema'

SCHEMA = begin
  file = open('https://raw.githubusercontent.com/awslabs/goformation/master/schema/sam.schema.json')
  JSON.parse File.read(file)
end

FILE = ARGV[0] || 'template.yaml'
PATH = File.expand_path(File.join(ENV['PWD'], FILE))

DATA = YAML.load(File.read(PATH))

begin
  JSON::Validator.validate! SCHEMA, DATA
  puts 'Valid!'
rescue JSON::Schema::ValidationError => e
  puts e.message
end