new_relic_agent.rb

# frozen_string_literal: true

# Cloud Foundry Java Buildpack
# Copyright 2013-2020 the original author or authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

require 'java_buildpack/component/versioned_dependency_component'
require 'java_buildpack/framework'

module JavaBuildpack
  module Framework

    # Encapsulates the functionality for enabling zero-touch New Relic support.
    class NewRelicAgent < JavaBuildpack::Component::VersionedDependencyComponent

      def initialize(context, &version_validator)
        super(context, &version_validator)

        extensions_context = context.clone
        extensions_context[:configuration] = context[:configuration]['extensions'] || {}

        return unless supports_extensions?(extensions_context[:configuration])

        @extensions = NewRelicAgentExtensions.new(extensions_context)
      end

      # (see JavaBuildpack::Component::BaseComponent#compile)
      def compile
        download_jar
        @extensions&.compile
        @droplet.copy_resources
      end

      # (see JavaBuildpack::Component::BaseComponent#release)
      def release
        credentials   = @application.services.find_service(FILTER, [LICENSE_KEY, LICENSE_KEY_USER])['credentials']
        java_opts     = @droplet.java_opts
        configuration = {}

        apply_configuration(credentials, configuration)
        apply_user_configuration(credentials, configuration)
        write_java_opts(java_opts, configuration)

        java_opts.add_javaagent(@droplet.sandbox + jar_name)
                 .add_system_property('newrelic.home', @droplet.sandbox)
        java_opts.add_system_property('newrelic.enable.java.8', 'true') if @droplet.java_home.java_8_or_later?
      end

      protected

      # (see JavaBuildpack::Component::VersionedDependencyComponent#supports?)
      def supports?
        @application.services.one_service? FILTER, [LICENSE_KEY, LICENSE_KEY_USER]
      end

      private

      FILTER = /newrelic/.freeze

      LICENSE_KEY = 'licenseKey'

      LICENSE_KEY_USER = 'license_key'

      private_constant :FILTER, :LICENSE_KEY, :LICENSE_KEY_USER

      def apply_configuration(credentials, configuration)
        configuration['log_file_name']  = 'STDOUT'
        configuration[LICENSE_KEY_USER] = credentials[LICENSE_KEY]
        configuration['app_name']       = @application.details['application_name']
      end

      def apply_user_configuration(credentials, configuration)
        credentials.each do |key, value|
          configuration[key] = value
        end
      end

      def supports_extensions?(configuration)
        !(configuration['repository_root'] || '').empty?
      end

      def write_java_opts(java_opts, configuration)
        configuration.each do |key, value|
          java_opts.add_system_property("newrelic.config.#{key}", value)
        end
      end

    end

    # Used by the main NewRelicAgent class to download the extensions tarball(if configured)
    class NewRelicAgentExtensions < JavaBuildpack::Component::VersionedDependencyComponent

      # (see JavaBuildpack::Component::VersionedDependencyComponent#initialize)
      def initialize(context, &version_validator)
        JavaBuildpack::Util::Cache::InternetAvailability.instance.available(
          true, 'The New Relic Extensions download location is always accessible'
        ) do
          super(context, &version_validator)
        end
      end

      # (see JavaBuildpack::Component::BaseComponent#compile)
      def compile
        JavaBuildpack::Util::Cache::InternetAvailability.instance.available(
          true, 'The New Relic Extensions download location is always accessible'
        ) do
          download_tar(true, @droplet.sandbox + 'extensions')
        end
      end

      # (see JavaBuildpack::Component::BaseComponent#release)
      def release; end

      # (see JavaBuildpack::Component::VersionedDependencyComponent#supports?)
      def supports?
        !(@configuration['repository_root'] || '').empty?
      end
    end

  end
end