WIP: AC/FC integration

lib/new_relic/agent/configuration/default_source.rb

@@ -2187,6 +2187,28 @@ def self.notify
           :transform => DefaultSource.method(:convert_to_constant_list),
           :description => 'Specify a list of exceptions you do not want the agent to strip when [strip_exception_messages](#strip_exception_messages-enabled) is `true`. Separate exceptions with a comma. For example, `"ImportantException,PreserveMessageException"`.'
         },
+        # Super Agent
+        :'superagent.fleet_id' => {
+          :default => 'j2e4a6n0v1', # TODO: set default to nil before release
+          :public => true,
+          :type => String,
+          :allowed_from_server => false,
+          :description => 'This assigns a fleet id to the language agent. This id is generated by the super agent. If this setting is present, it indicates the agent is running in a super agent/fleet environment and health file(s) will be generated.'
+        },
+        :'superagent.health.delivery_location' => {
+          :default => 'health/', # TODO: set default to EMPTY_STRING before release
+          :public => true,
+          :type => String,
+          :allowed_from_server => false,
+          :description => 'A `file:` URI that specifies the fully qualified directory path for health file(s) to be written to. For example: `file:///var/lib/newrelic-super-agent/fleet/agents.d/<fleet_id>`. This configuration will be set by the super agent, or one of its components, prior to agent startup.'
+        },
+        :'superagent.health.frequency' => {
+          :default => 5,
+          :public => true,
+          :type => Integer,
+          :allowed_from_server => false,
+          :description => 'The interval, in seconds, of how often the health file(s) will be written to. This configuration will be set by the super agent, or one of its components, prior to agent startup.'
+        },
         # Thread profiler
         :'thread_profiler.enabled' => {
           :default => DefaultSource.thread_profiler_enabled,

lib/new_relic/agent/health_check.rb

@@ -0,0 +1,78 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+module NewRelic
+  module Agent
+    class HealthCheck
+      def initialize
+        # should we pass this in as an arg from the init_plugin method call?
+        @start_time = nano_time
+        # if they're configs, is it worth saving them in vars?
+        @fleet_id = NewRelic::Agent.config[:'superagent.fleet_id']
+        @delivery_location = NewRelic::Agent.config[:'superagent.health.delivery_location']
+        @frequency = NewRelic::Agent.config[:'superagent.health.frequency']
+        # @check? = false
+      end
+
+      # nope out if no delivery_location?
+      # seems like something for init_plugin
+      def validate_delivery_location
+      end
+
+      # TODO: check health
+      def health
+        'health: true'
+      end
+
+      # TODO: get valid status
+      def status
+        'status: Agent has shutdown'
+      end
+
+      # TODO: get actual last error
+      def last_error
+        'last_error: NR-APM-1000'
+      end
+
+      def start_time
+        "start_time_unix_nano: #{@start_time}"
+      end
+
+      def status_time
+        "status_time_unix_nano: #{nano_time}"
+      end
+
+      def nano_time
+        Process.clock_gettime(Process::CLOCK_REALTIME, :nanosecond)
+      end
+
+      def file_name
+        "health-#{NewRelic::Agent::GuidGenerator.generate_guid(32)}.yml"
+      end
+
+      def write_file
+        @path ||= find_or_create_file_path
+
+        File.write("#{@path}/#{file_name}", contents)
+      end
+
+      def contents
+        # TODO: should I add .to_yaml?
+        [health, status, last_error, status_time, start_time].join("\n")
+      end
+
+      # Adapted from AgentLogger
+      # rescue?
+      def find_or_create_file_path
+        for abs_path in [File.expand_path(@delivery_location),
+          File.expand_path(File.join('', @delivery_location))] do
+          if File.directory?(abs_path) || (Dir.mkdir(abs_path) rescue nil)
+            return abs_path[%r{^(.*?)/?$}]
+          end
+        end
+        nil
+      end
+    end
+  end
+end

lib/new_relic/control/instance_methods.rb

@@ -5,6 +5,7 @@
 require 'new_relic/agent/null_logger'
 require 'new_relic/agent/memory_logger'
 require 'new_relic/agent/agent_logger'
+require 'new_relic/agent/health_check'
 
 require_relative 'private_instance_methods'
 
@@ -53,7 +54,7 @@ def init_plugin(options = {})
         env = determine_env(options)
 
         configure_agent(env, options)
-
+        # health_check
         # Be sure to only create once! RUBY-1020
         create_logger(options)
 
@@ -153,6 +154,14 @@ def newrelic_root
         self.class.newrelic_root
       end
 
+      def health_check
+        return NewRelic::Agent.logger.debug('superagent.fleet_id not found, skipping health checks') unless NewRelic::Agent.config[:'superagent.fleet_id']
+        return NewRelic::Agent.logger.debug('superagent.health.file_destination not found, skipping health checks') unless NewRelic::Agent.config[:'superagent.health.delivery_location']
+
+        # NewRelic::Agent::HealthCheck.new
+        # start the loop here?
+      end
+
       protected
 
       def initialize(local_env, config_file_override = nil)

test/new_relic/agent/health_check_test.rb

@@ -0,0 +1,145 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+require 'fileutils'
+require_relative '../../test_helper'
+
+class NewRelicHealthCheckTest < Minitest::Test
+  # example:
+  # health-bc21b5891f5e44fc9272caef924611a8.yml
+  # healthy: false
+  # status: Agent has shutdown
+  # last_error: NR-APM-1000
+  # status_time_unix_nano: 1724953624761000000
+  # start_time_unix_nano: 1724953587605000000
+
+  # maybe delete the file every time?
+  # def teardown
+  #   FileUtils.rm_rf('health')
+  # end
+
+  def test_yaml_health_file_written_to_delivery_location
+    with_config(:'superagent.health.delivery_location' => 'health/') do
+      NewRelic::Agent::GuidGenerator.stub(:generate_guid, 'abc123') do
+        health_check = NewRelic::Agent::HealthCheck.new
+        health_check.write_file
+
+        assert File.directory?('health'), 'Directory not found'
+        assert File.exist?('health/health-abc123.yml'), 'File not found' # rubocop:disable Minitest/AssertPathExists
+      end
+    end
+  ensure
+    FileUtils.rm_rf('health')
+  end
+
+  # This might be on init...
+  def test_yaml_health_file_logs_error_when_delivery_location_invalid
+  end
+
+  def test_yaml_file_generated_if_superagent_fleet_id_present
+  end
+
+  def test_yaml_file_not_generated_if_superagent_fleet_id_absent
+  end
+
+  def test_yaml_file_name_has_health_plus_uuid_without_hyphens
+    health_check = NewRelic::Agent::HealthCheck.new
+    # ex: health-bc21b5891f5e44fc9272caef924611a8.yml
+    assert_match(/health-(.*){32}\.ya?ml/, health_check.file_name)
+  end
+
+  def test_yaml_health_file_written_on_interval
+    with_config(:'superagent.health.frequency' => 5) do
+    end
+  end
+
+  def test_agent_logs_errors_if_yaml_health_file_writing_fails
+  end
+
+  def test_yaml_file_has_health_field
+    with_config(:'superagent.health.delivery_location' => 'health/') do
+      NewRelic::Agent::GuidGenerator.stub(:generate_guid, 'abc123') do
+        health_check = NewRelic::Agent::HealthCheck.new
+        health_check.write_file
+
+        assert_predicate File.readlines('health/health-abc123.yml').grep(/health:/), :any?
+      end
+    end
+  ensure
+    FileUtils.rm_rf('health')
+  end
+
+  def test_yaml_file_has_status_field
+    with_config(:'superagent.health.delivery_location' => 'health/') do
+      NewRelic::Agent::GuidGenerator.stub(:generate_guid, 'abc123') do
+        health_check = NewRelic::Agent::HealthCheck.new
+        health_check.write_file
+
+        assert_predicate File.readlines('health/health-abc123.yml').grep(/status:/), :any?
+      end
+    end
+  ensure
+    FileUtils.rm_rf('health')
+  end
+
+  def test_yaml_file_has_last_error_field_when_status_not_healthy
+    with_config(:'superagent.health.delivery_location' => 'health/') do
+      NewRelic::Agent::GuidGenerator.stub(:generate_guid, 'abc123') do
+        health_check = NewRelic::Agent::HealthCheck.new
+        health_check.write_file
+
+        assert_predicate File.readlines('health/health-abc123.yml').grep(/last_error:/), :any?
+      end
+    end
+  ensure
+    FileUtils.rm_rf('health')
+  end
+
+  def test_yaml_file_does_not_have_last_error_field_when_status_healthy
+  end
+
+  def test_yaml_file_has_start_time_unix_nano
+    # TODO: - validate timestamp
+    # TODO - validate timestamp same for every file created by that instance
+    with_config(:'superagent.health.delivery_location' => 'health/') do
+      NewRelic::Agent::GuidGenerator.stub(:generate_guid, 'abc123') do
+        health_check = NewRelic::Agent::HealthCheck.new
+        health_check.write_file
+
+        assert_predicate File.readlines('health/health-abc123.yml').grep(/start_time_unix_nano:/), :any?
+      end
+    end
+  ensure
+    FileUtils.rm_rf('health')
+  end
+
+  def test_yaml_file_has_status_time_unix_nano
+    # status_time_unix_nano:
+    # timestamp present
+    # timestamp in nanoseconds => milliseconds * 1000000
+    with_config(:'superagent.health.delivery_location' => 'health/') do
+      NewRelic::Agent::GuidGenerator.stub(:generate_guid, 'abc123') do
+        health_check = NewRelic::Agent::HealthCheck.new
+        health_check.write_file
+
+        assert_predicate File.readlines('health/health-abc123.yml').grep(/status_time_unix_nano:/), :any?
+      end
+    end
+  ensure
+    FileUtils.rm_rf('health')
+  end
+
+  def test_yaml_file_fully_regenerated_on_each_interval
+  end
+
+  def test_unique_health_file_exists_per_process
+    # puma scenario?
+  end
+
+  def test_supportability_metric_generated_at_agent_startup
+    # Supportability/SuperAgent/Health/enabled
+  end
+
+  ## ADD MORE TESTS FOR ERROR CODE BEHAVIOR
+end