Module: NewRelic::Agent::Hostname

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

Constant Summary collapse

CLOUD_RUN_REVISION_VARS =

Cloud Run sets a different revision variable per resource type: K_REVISION on a Service, CLOUD_RUN_REVISION on a Worker Pool, and CLOUD_RUN_EXECUTION on a Job. The first non-empty value identifies Cloud Run and names the revision. https://docs.cloud.google.com/run/docs/container-contract#env-vars

%w[K_REVISION CLOUD_RUN_REVISION CLOUD_RUN_EXECUTION].freeze
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

.cloud_run_revision ⇒ Object

The revision (Service, Worker Pool) or execution (Job) name for the Cloud Run resource this process belongs to, or nil when not on Cloud Run.



39
40
41
 
# File 'lib/new_relic/agent/hostname.rb', line 39

def self.cloud_run_revision
  CLOUD_RUN_REVISION_VARS.map { |var| ENV[var] }.find { |value| value && !value.empty? }
end

.gcp_cloud_run? ⇒ Boolean

Returns:

  • (Boolean) 


32
33
34
35
 
# File 'lib/new_relic/agent/hostname.rb', line 32

def self.gcp_cloud_run?
  !cloud_run_revision.nil? &&
    ::NewRelic::Agent.config[:'utilization.gcp_cloud_run.use_instance_as_host']
end

.gcp_cloud_run_host ⇒ Object 



43
44
45
46
47
48
49
50
51
52
 
# File 'lib/new_relic/agent/hostname.rb', line 43

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']
    "#{cloud_run_revision}-#{instance_id}"
  else
    instance_id
  end
end

.gcp_instance_id ⇒ Object 



54
55
56
57
58
59
60
61
62
63
 
# File 'lib/new_relic/agent/hostname.rb', line 54

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 



19
20
21
22
23
24
25
26
27
28
29
30
 
# File 'lib/new_relic/agent/hostname.rb', line 19

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 



89
90
91
 
# File 'lib/new_relic/agent/hostname.rb', line 89

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

.get_external(host_or_ip) ⇒ Object 



107
108
109
 
# File 'lib/new_relic/agent/hostname.rb', line 107

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.



72
73
74
75
76
77
78
79
80
81
 
# File 'lib/new_relic/agent/hostname.rb', line 72

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 



83
84
85
86
87
 
# File 'lib/new_relic/agent/hostname.rb', line 83

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) 


103
104
105
 
# File 'lib/new_relic/agent/hostname.rb', line 103

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