Class: Hiera::Backend::Cfn_metadata_backend

Inherits:
Object
  • Object
show all
Defined in:
lib/hiera/backend/cfn_metadata_backend.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Cfn_metadata_backend

Returns a new instance of Cfn_metadata_backend.



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# File 'lib/hiera/backend/cfn_metadata_backend.rb', line 6

def initialize()
  require 'aws-sdk-core'
  require 'hiera-cfn-metadata'

  @config = Config[:cfn_metadata]
  stack = @config[:stack] || ENV['CFN_STACK']
  resource = @config[:resource] || ENV['CFN_RESOURCE']

  begin
    cfn = Aws::CloudFormation::Client.new(
      region: @config[:region] || ENV['AWS_REGION'],
      credentials: Aws::InstanceIdentityCredentials.new(),
    )

    resp = cfn.describe_stack_resource({
      stack_name: stack,
      logical_resource_id: resource
    })
    raise resp.error if !resp.successful?

    metadata = resp.stack_resource_detail.metadata

    @datasources = JSON.parse(metadata)
    p @datasources

  rescue Exception => e
    @datasources = nil
    Hiera.warn("[hiera-cfn-metadata] Skipping backend. Configuration error: #{e}")
  end
end

Instance Method Details

#lookup(key, scope, order_override, resolution_type) ⇒ Object 



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# File 'lib/hiera/backend/cfn_metadata_backend.rb', line 37

def lookup(key, scope, order_override, resolution_type)
  answer = nil
  return answer if @datasources.nil?

  Hiera.debug("[hiera-cfn-metadata] Looking up #{key}")

  Backend.datasources(scope, order_override) do |source|
    Hiera.debug("[hiera-cfn-metadata] Looking for data source #{source}")

    data = @datasources[source]
    next if data.nil?
    next unless data.include?(key)

    # for array resolution we just append to the array whatever
    # we find, we then goes onto the next file and keep adding to
    # the array
    #
    # for priority searches we break after the first found data item
    new_answer = Backend.parse_answer(data[key], scope)
    case resolution_type
    when :array
      raise Exception, "[hiera-cfn-metadata] Hiera type mismatch for key '#{key}': expected Array and got #{new_answer.class}" unless new_answer.kind_of? Array or new_answer.kind_of? String
      answer ||= []
      answer << new_answer
    when :hash
      raise Exception, "[hiera-cfn-metadata] Hiera type mismatch for key '#{key}': expected Hash and got #{new_answer.class}" unless new_answer.kind_of? Hash
      answer ||= {}
      answer = Backend.merge_answer(new_answer, answer)
    else
      answer = new_answer
      break
    end
  end

  return answer
end