Class: OneApm::LocalEnvironment

Inherits:
Object
  • Object
show all
Defined in:
lib/one_apm/support/local_environment.rb

Overview

This class is responsible for determining the ‘dispatcher’ in use by the current process. The dispatcher might be a recognized web server such as unicorn or passenger, a background job processor such as resque or sidekiq, or nil for unknown.

Dispatcher detection is best-effort, and serves two purposes:

  1. For some dispatchers, we need to apply specific workarounds in order for the agent to work correctly.

  2. When reading logs, since multiple processes on a given host might write into the same log, it’s useful to be able to identify what kind of process a given PID mapped to.

Overriding the dispatcher is possible via the ONEAPM_DISPATCHER environment variable, but this should not generally be necessary unless you’re on a dispatcher that falls into category 1 above, and our detection logic isn’t working correctly.

If the environment can’t be determined, it will be set to nil.

OneApm::LocalEnvironment should be accessed through OneApm::Probe#env (via the OneApm::Probe singleton).

Instance Method Summary collapse

Constructor Details

#initialize ⇒ LocalEnvironment

Returns a new instance of LocalEnvironment.



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# File 'lib/one_apm/support/local_environment.rb', line 34

def initialize
  # Extend self with any any submodules of LocalEnvironment.  These can override
  # the discover methods to discover new framworks and dispatchers.
  OneApm::LocalEnvironment.constants.each do | const |
    mod = OneApm::LocalEnvironment.const_get const
    self.extend mod if mod.instance_of? Module
  end
  discover_dispatcher
end

Instance Method Details

#discovered_dispatcher ⇒ Object 



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# File 'lib/one_apm/support/local_environment.rb', line 29

def discovered_dispatcher
  discover_dispatcher unless @discovered_dispatcher
  @discovered_dispatcher
end

#executable ⇒ Object 



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# File 'lib/one_apm/support/local_environment.rb', line 197

def executable
  File.basename($0)
end

#find_class_in_object_space(klass) ⇒ Object

Runs through all the objects in ObjectSpace to find the first one that match the provided class



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# File 'lib/one_apm/support/local_environment.rb', line 46

def find_class_in_object_space(klass)
  if OneApm::LanguageSupport.object_space_usable?
    ObjectSpace.each_object(klass) do |x|
      return x
    end
  end
  return nil
end

#to_s ⇒ Object

outputs a human-readable description



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# File 'lib/one_apm/support/local_environment.rb', line 191

def to_s
  s = "LocalEnvironment["
  s << ";dispatcher=#{@discovered_dispatcher}" if @discovered_dispatcher
  s << "]"
end