Module: NewRelic::Agent::Hostname

Defined in:
lib/new_relic/agent/hostname.rb

Constant Summary collapse

CLOUD_RUN_REVISION = 
'K_REVISION'
GCP_INSTANCE_ID_URI = 
'http://metadata.google.internal/computeMetadata/v1/instance/id'
GCP_METADATA_HEADERS = 
{'Metadata-Flavor' => 'Google'}.freeze
LOCALHOST = 
%w[
  localhost
  0.0.0.0
  127.0.0.1
  0:0:0:0:0:0:0:1
  0:0:0:0:0:0:0:0
  ::1
  ::
].freeze

Class Method Summary collapse

Class Method Details

.gcp_cloud_run? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/hostname.rb', line 28

def self.gcp_cloud_run?
  ENV.key?(CLOUD_RUN_REVISION) &&
    ::NewRelic::Agent.config[:'utilization.gcp_cloud_run.use_instance_as_host']
end

.gcp_cloud_run_host ⇒ Object 



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# File 'lib/new_relic/agent/hostname.rb', line 33

def self.gcp_cloud_run_host
  instance_id = gcp_instance_id
  return Socket.gethostname.force_encoding(Encoding::UTF_8) unless instance_id

  if ::NewRelic::Agent.config[:'utilization.gcp_cloud_run.include_revision_in_host']
    "#{ENV[CLOUD_RUN_REVISION]}-#{instance_id}"
  else
    instance_id
  end
end

.gcp_instance_id ⇒ Object 



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# File 'lib/new_relic/agent/hostname.rb', line 44

def self.gcp_instance_id
  response = NewRelic::Helper.fetch_metadata(GCP_INSTANCE_ID_URI, GCP_METADATA_HEADERS)
  return unless response&.code == '200'

  id = response.body.to_s.strip
  id.empty? ? nil : id
rescue => e
  NewRelic::Agent.logger.debug("Unable to fetch GCP Cloud Run instance id: #{e.class} - #{e.message}")
  nil
end

.get ⇒ Object 



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# File 'lib/new_relic/agent/hostname.rb', line 15

def self.get
  dyno_name = ENV['DYNO']
  @hostname ||= if dyno_name && ::NewRelic::Agent.config[:'heroku.use_dyno_names']
    matching_prefix = heroku_dyno_name_prefix(dyno_name)
    dyno_name = "#{matching_prefix}.*" if matching_prefix
    dyno_name
  elsif gcp_cloud_run?
    gcp_cloud_run_host
  else
    Socket.gethostname.force_encoding(Encoding::UTF_8)
  end
end

.get_dyno_prefixes ⇒ Object 



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# File 'lib/new_relic/agent/hostname.rb', line 79

def self.get_dyno_prefixes
  ::NewRelic::Agent.config[:'heroku.dyno_name_prefixes_to_shorten']
end

.get_external(host_or_ip) ⇒ Object 



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# File 'lib/new_relic/agent/hostname.rb', line 97

def self.get_external(host_or_ip)
  local?(host_or_ip) ? get : host_or_ip
end

.get_fqdn ⇒ Object

Pass '-f' to the external executable 'hostname' to request the fully qualified domain name (fqdn). For implementations of 'hostname' that do not support '-f' (such as the one OpenBSD ships with), fall back to calling 'hostname' without the '-f'. If both ways of calling 'hostname' fail, or in a context where 'hostname' is not even available (within an AWS Lambda function, for example), call the 'get' method which uses Socket instead of an external executable.



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

def self.get_fqdn
  begin
    NewRelic::Helper.run_command('hostname -f')
  rescue NewRelic::CommandRunFailedError
    NewRelic::Helper.run_command('hostname')
  end
rescue NewRelic::CommandExecutableNotFoundError, NewRelic::CommandRunFailedError => e
  NewRelic::Agent.logger.debug("#{e.class} - #{e.message}")
  get
end

.heroku_dyno_name_prefix(dyno_name) ⇒ Object 



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# File 'lib/new_relic/agent/hostname.rb', line 73

def self.heroku_dyno_name_prefix(dyno_name)
  get_dyno_prefixes.find do |dyno_prefix|
    dyno_name.start_with?(dyno_prefix + '.')
  end
end

.local?(host_or_ip) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/new_relic/agent/hostname.rb', line 93

def self.local?(host_or_ip)
  LOCALHOST.include?(host_or_ip)
end