Class: NewRelic::Agent::Configuration::Manager

Inherits:
Object
  • Object
show all
Defined in:
lib/new_relic/agent/configuration/manager.rb

Constant Summary collapse

DEPENDENCY_DETECTION_VALUES = 
%i[prepend chain unsatisfied].freeze
MALFORMED_LABELS_WARNING = 
'Skipping malformed labels configuration'
PARSING_LABELS_FAILURE = 
'Failure during parsing labels. Ignoring and carrying on with connect.'
MAX_LABEL_COUNT = 
64
MAX_LABEL_LENGTH = 
255

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Manager

Returns a new instance of Manager.



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# File 'lib/new_relic/agent/configuration/manager.rb', line 34

def initialize
  reset_to_defaults
  @callbacks = Hash.new { |hash, key| hash[key] = [] }
end

Instance Method Details

#[](key) ⇒ Object

Defining these explicitly saves object allocations that we incur if we use Forwardable and def_delegators.



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# File 'lib/new_relic/agent/configuration/manager.rb', line 22

def [](key)
  @cache[key]
end

#add_config_for_testing(source, level = 0) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 39

def add_config_for_testing(source, level = 0)
  raise 'Invalid config type for testing' unless [Hash, DottedHash].include?(source.class)

  invoke_callbacks(:add, source)
  @configs_for_testing << [source.freeze, level]
  reset_cache
  log_config(:add, source)
end

#apply_mask(hash) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 225

def apply_mask(hash)
  MASK_DEFAULTS \
    .select { |_, proc| proc.call } \
    .each { |key, _| hash.delete(key) }
  hash
end

#apply_transformations(key, value) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 143

def apply_transformations(key, value)
  if transform = transform_from_default(key)
    begin
      transform.call(value)
    rescue => e
      ::NewRelic::Agent.logger.error("Error applying transformation for #{key}, pre-transform value was: #{value}.", e)
      raise e
    end
  else
    value
  end
end

#break_label_string_into_pairs(labels) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 270

def break_label_string_into_pairs(labels)
  stripped_labels = labels.strip.sub(/^;*/, '').sub(/;*$/, '')
  stripped_labels.split(';').map do |pair|
    pair.split(':').map(&:strip)
  end
end

#config_classes_for_testing ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 403

def config_classes_for_testing
  config_stack.map(&:class)
end

#delete_all_configs_for_testing ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 388

def delete_all_configs_for_testing
  @security_policy_source = nil
  @high_security_source = nil
  @environment_source = nil
  @server_source = nil
  @manual_source = nil
  @yaml_source = nil
  @default_source = nil
  @configs_for_testing = []
end

#evaluate_and_apply_transformations(key, value) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 139

def evaluate_and_apply_transformations(key, value)
  apply_transformations(key, evaluate_procs(value))
end

#evaluate_procs(value) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 131

def evaluate_procs(value)
  if value.respond_to?(:call)
    instance_eval(&value)
  else
    value
  end
end

#fetch(key) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 113

def fetch(key)
  config_stack.each do |config|
    next unless config

    accessor = key.to_sym

    if config.has_key?(accessor)
      begin
        return evaluate_and_apply_transformations(accessor, config[accessor])
      rescue
        next
      end
    end
  end

  nil
end

#finished_configuring? ⇒ Boolean

Returns:



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# File 'lib/new_relic/agent/configuration/manager.rb', line 205

def finished_configuring?
  !@server_source.nil?
end

#flattened ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 209

def flattened
  config_stack.reverse.inject({}) do |flat, layer|
    thawed_layer = layer.to_hash.dup
    thawed_layer.each do |k, v|
      begin
        thawed_layer[k] = instance_eval(&v) if v.respond_to?(:call)
      rescue => e
        ::NewRelic::Agent.logger.debug("#{e.class.name} : #{e.message} - when accessing config key #{k}")
        thawed_layer[k] = nil
      end
      thawed_layer.delete(:config)
    end
    flat.merge(thawed_layer.to_hash)
  end
end

#has_key?(key) ⇒ Boolean

Returns:



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# File 'lib/new_relic/agent/configuration/manager.rb', line 26

def has_key?(key)
  @cache.has_key?(key)
end

#invoke_callbacks(direction, source) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 165

def invoke_callbacks(direction, source)
  return unless source

  source.keys.each do |key|
    begin
      # we need to evaluate and apply transformations for the value to deal with procs as values
      # this is usually done by the fetch method when accessing config, however the callbacks bypass that
      evaluated_cache = evaluate_and_apply_transformations(key, @cache[key])
      evaluated_source = evaluate_and_apply_transformations(key, source[key])
    rescue
      next
    end

    if evaluated_cache != evaluated_source
      @callbacks[key].each do |proc|
        if direction == :add
          proc.call(evaluated_source)
        else
          proc.call(evaluated_cache)
        end
      end
    end
  end
end

#keys ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 30

def keys
  @cache.keys
end

#limit_number_of_labels(pairs) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 328

def limit_number_of_labels(pairs)
  if pairs.length > MAX_LABEL_COUNT
    NewRelic::Agent.logger.warn("Too many labels defined. Only taking first #{MAX_LABEL_COUNT}")
    pairs[0...64]
  else
    pairs
  end
end

#log_config(direction, source) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 378

def log_config(direction, source)
  # Just generating this log message (specifically calling
  # flattened.inspect) is expensive enough that we don't want to do it
  # unless we're actually going to be logging the message based on our
  # current log level.
  ::NewRelic::Agent.logger.debug do
    "Updating config (#{direction}) from #{source.class}. Results: #{flattened.inspect}"
  end
end

#make_label_hash(pairs, labels = nil) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 295

def make_label_hash(pairs, labels = nil)
  # This can accept a hash, so force it down to an array of pairs first
  pairs = Array(pairs)

  unless valid_label_pairs?(pairs)
    NewRelic::Agent.logger.warn("#{MALFORMED_LABELS_WARNING}: #{labels || pairs}")
    return NewRelic::EMPTY_ARRAY
  end

  pairs = limit_number_of_labels(pairs)
  pairs = remove_duplicates(pairs)
  pairs.map do |key, value|
    {
      'label_type' => truncate(key),
      'label_value' => truncate(value.to_s, key)
    }
  end
end

#new_cache ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 374

def new_cache
  @cache = Hash.new { |hash, key| hash[key] = self.fetch(key) }
end

#notify_finished_configuring ⇒ Object

This event is intended to be fired once during the entire lifespan of an agent run, after the server source has been applied for the first time. This should indicate that all configuration has been applied, and the main functions of the agent are safe to start.



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# File 'lib/new_relic/agent/configuration/manager.rb', line 201

def notify_finished_configuring
  NewRelic::Agent.instance.events.notify(:initial_configuration_complete)
end

#notify_server_source_added ⇒ Object

This event is intended to be fired every time the server source is applied. This happens after the agent’s initial connect, and again on every forced reconnect.



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# File 'lib/new_relic/agent/configuration/manager.rb', line 193

def notify_server_source_added
  NewRelic::Agent.instance.events.notify(:server_source_configuration_added)
end

#num_configs_for_testing ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 399

def num_configs_for_testing
  config_stack.size
end

#parse_labels_from_dictionary ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 343

def parse_labels_from_dictionary
  make_label_hash(NewRelic::Agent.config[:labels])
end

#parse_labels_from_string ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 264

def parse_labels_from_string
  labels = NewRelic::Agent.config[:labels]
  label_pairs = break_label_string_into_pairs(labels)
  make_label_hash(label_pairs, labels)
end

#parsed_labels ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 252

def parsed_labels
  case NewRelic::Agent.config[:labels]
  when String
    parse_labels_from_string
  else
    parse_labels_from_dictionary
  end
rescue => e
  NewRelic::Agent.logger.error(PARSING_LABELS_FAILURE, e)
  NewRelic::EMPTY_ARRAY
end

#register_callback(key) {|| ... } ⇒ Object

Yields:

  • () 


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# File 'lib/new_relic/agent/configuration/manager.rb', line 160

def register_callback(key, &proc)
  @callbacks[key] << proc
  yield(@cache[key])
end

#remove_config(source) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 62

def remove_config(source)
  case source
  when SecurityPolicySource then @security_policy_source = nil
  when HighSecuritySource then @high_security_source = nil
  when EnvironmentSource then @environment_source = nil
  when ServerSource then @server_source = nil
  when ManualSource then @manual_source = nil
  when YamlSource then @yaml_source = nil
  when DefaultSource then @default_source = nil
  else
    @configs_for_testing.delete_if { |src, lvl| src == source }
  end

  reset_cache
  invoke_callbacks(:remove, source)
  log_config(:remove, source)
end

#remove_config_type(sym) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 48

def remove_config_type(sym)
  source = case sym
  when :security_policy then @security_policy_source
  when :high_security then @high_security_source
  when :environment then @environment_source
  when :server then @server_source
  when :manual then @manual_source
  when :yaml then @yaml_source
  when :default then @default_source
  end

  remove_config(source)
end

#remove_duplicates(pairs) ⇒ Object

We only take the last value provided for a given label type key



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# File 'lib/new_relic/agent/configuration/manager.rb', line 338

def remove_duplicates(pairs)
  grouped_by_type = pairs.group_by(&:first)
  grouped_by_type.values.map(&:last)
end

#replace_or_add_config(source) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 80

def replace_or_add_config(source)
  source.freeze
  was_finished = finished_configuring?

  invoke_callbacks(:add, source)

  case source
  when SecurityPolicySource then @security_policy_source = source
  when HighSecuritySource then @high_security_source = source
  when EnvironmentSource then @environment_source = source
  when ServerSource then @server_source = source
  when ManualSource then @manual_source = source
  when YamlSource then @yaml_source = source
  when DefaultSource then @default_source = source
  else
    NewRelic::Agent.logger.warn("Invalid config format; config will be ignored: #{source}")
  end

  reset_cache
  log_config(:add, source)

  notify_server_source_added if ServerSource === source
  notify_finished_configuring if !was_finished && finished_configuring?
end

#reset_cache ⇒ Object

reset the configuration hash, but do not replace previously auto determined dependency detection values with nil or ‘auto’



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# File 'lib/new_relic/agent/configuration/manager.rb', line 364

def reset_cache
  return new_cache unless defined?(@cache) && @cache

  preserved = @cache.select { |_k, v| DEPENDENCY_DETECTION_VALUES.include?(v) }
  new_cache
  preserved.each { |k, v| @cache[k] = v }

  @cache
end

#reset_to_defaults ⇒ Object

Generally only useful during initial construction and tests



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# File 'lib/new_relic/agent/configuration/manager.rb', line 348

def reset_to_defaults
  @security_policy_source = nil
  @high_security_source = nil
  @environment_source = EnvironmentSource.new
  @server_source = nil
  @manual_source = nil
  @yaml_source = nil
  @default_source = DefaultSource.new

  @configs_for_testing = []

  reset_cache
end

#source(key) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 105

def source(key)
  config_stack.each do |config|
    if config.respond_to?(key.to_sym) || config.has_key?(key.to_sym)
      return config
    end
  end
end

#to_collector_hash ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 232

def to_collector_hash
  DottedHash.new(apply_mask(flattened)).to_hash.delete_if do |k, v|
    default = DEFAULTS[k]
    if default
      default[:exclude_from_reported_settings]
    else
      # In our tests, we add totally bogus configs, because testing.
      # In those cases, there will be no default. So we'll just let
      # them through.
      false
    end
  end
end

#transform_from_default(key) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 156

def transform_from_default(key)
  ::NewRelic::Agent::Configuration::DefaultSource.transform_for(key)
end

#truncate(text, key = nil) ⇒ Object 



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# File 'lib/new_relic/agent/configuration/manager.rb', line 314

def truncate(text, key = nil)
  if text.length > MAX_LABEL_LENGTH
    if key
      msg = "The value for the label '#{key}' is longer than the allowed #{MAX_LABEL_LENGTH} and will be truncated. Value = '#{text}'"
    else
      msg = "Label name longer than the allowed #{MAX_LABEL_LENGTH} will be truncated. Name = '#{text}'"
    end
    NewRelic::Agent.logger.warn(msg)
    text[0..MAX_LABEL_LENGTH - 1]
  else
    text
  end
end

#valid_label_item?(item) ⇒ Boolean

Returns:



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# File 'lib/new_relic/agent/configuration/manager.rb', line 285

def valid_label_item?(item)
  case item
  when String then !item.empty?
  when Numeric then true
  when true then true
  when false then true
  else false
  end
end

#valid_label_pairs?(label_pairs) ⇒ Boolean

Returns:



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# File 'lib/new_relic/agent/configuration/manager.rb', line 277

def valid_label_pairs?(label_pairs)
  label_pairs.all? do |pair|
    pair.length == 2 &&
      valid_label_item?(pair.first) &&
      valid_label_item?(pair.last)
  end
end