Module: Vivarium

Defined in:

lib/vivarium.rb,
lib/vivarium/logger.rb,
lib/vivarium/version.rb

Defined Under Namespace

Classes: Daemon, Error, Event, Logger, MapStore, ObservationSession

Constant Summary

PIN_DIR =

ENV.fetch("VIVARIUM_BPF_PIN_DIR", "/sys/fs/bpf/vivarium")

CONFIG_ROOT_TARGETS_PIN =

File.join(PIN_DIR, "config_root_targets")

CONFIG_SPAWNED_TARGETS_PIN =

File.join(PIN_DIR, "config_spawned_targets")

CONFIG_TARGETS_PIN =

CONFIG_ROOT_TARGETS_PIN

EVENT_INVOKED_PIN =

File.join(PIN_DIR, "event_invoked")

EVENT_WRITE_POS_PIN =

File.join(PIN_DIR, "event_write_pos")

EVENT_NAME_SIZE =

16

EVENT_PAYLOAD_SIZE =

256

EVENT_STRUCT_SIZE =

4 + EVENT_NAME_SIZE + EVENT_PAYLOAD_SIZE

EVENT_CAPACITY =

64

VERSION =

"0.1.1"

Class Attribute Summary

• .bpf_pin_dir ⇒ Object

Class Method Summary

• .build_observe_tracepoint(store, logger) ⇒ Object
• .filter_internal_frames? ⇒ Boolean
• .observe(pin_dir: bpf_pin_dir, logger: nil, dest: $stdout, format: :human) ⇒ Object
• .run_daemon!(argv = ARGV) ⇒ Object
• .scoped_observe(pin_dir:, logger:, dest:, format:) ⇒ Object
• .top_observe(pin_dir: bpf_pin_dir, logger: nil, dest: $stdout, format: :human) ⇒ Object

Class Attribute Details

.bpf_pin_dir ⇒ Object

# File 'lib/vivarium.rb', line 31

def bpf_pin_dir
  @bpf_pin_dir || PIN_DIR
end

Class Method Details

.build_observe_tracepoint(store, logger) ⇒ Object

# File 'lib/vivarium.rb', line 436

def self.build_observe_tracepoint(store, logger)
  TracePoint.new(:return, :c_return) do |tp|
    events = store.drain_events
    next if events.empty?

    stack = caller_locations(2, 16)
    stack = stack.reject { |loc| loc.path.to_s.include?("vivarium") } if filter_internal_frames?
    logger.log(events, tp, stack)
  end
end

.filter_internal_frames? ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/vivarium.rb', line 447

def self.filter_internal_frames?
  value = ENV["VIVARIUM_FILTER_INTERNAL_FRAMES"]
  return true if value.nil?

  !%w[0 false off no].include?(value.strip.downcase)
end

.observe(pin_dir: bpf_pin_dir, logger: nil, dest: $stdout, format: :human) ⇒ Object

# File 'lib/vivarium.rb', line 399

def self.observe(pin_dir: bpf_pin_dir, logger: nil, dest: $stdout, format: :human)
  return scoped_observe(pin_dir: pin_dir, logger: logger, dest: dest, format: format) { yield } if block_given?

  top_observe(pin_dir: pin_dir, logger: logger, dest: dest, format: format)
end

.run_daemon!(argv = ARGV) ⇒ Object

# File 'lib/vivarium.rb', line 454

def self.run_daemon!(argv = ARGV)
  options = { pin_dir: bpf_pin_dir }
  OptionParser.new do |opts|
    opts.banner = "Usage: vivariumd [--pin-dir PATH]"
    opts.on("--pin-dir PATH", "Pinned map directory") { |v| options[:pin_dir] = v }
  end.parse!(argv)

  Daemon.new(pin_dir: options[:pin_dir]).run
end

.scoped_observe(pin_dir:, logger:, dest:, format:) ⇒ Object

# File 'lib/vivarium.rb', line 420

def self.scoped_observe(pin_dir:, logger:, dest:, format:)
  logger ||= Logger.new(dest: dest, format: format)
  store = MapStore.new(pin_dir: pin_dir)
  pid = Process.pid
  store.register_pid(pid)
  logger.info("scoped observing with pid=#{pid}")

  tracer = build_observe_tracepoint(store, logger)
  tracer.enable

  yield
ensure
  tracer&.disable
  store&.unregister_pid(pid)
end

.top_observe(pin_dir: bpf_pin_dir, logger: nil, dest: $stdout, format: :human) ⇒ Object

# File 'lib/vivarium.rb', line 405

def self.top_observe(pin_dir: bpf_pin_dir, logger: nil, dest: $stdout, format: :human)
  logger ||= Logger.new(dest: dest, format: format)
  store = MapStore.new(pin_dir: pin_dir)
  pid = Process.pid
  store.register_pid(pid)
  logger.info("top-level observing with pid=#{pid}")

  tracer = build_observe_tracepoint(store, logger)
  tracer.enable

  session = ObservationSession.new(store: store, pid: pid, tracer: tracer)
  at_exit { session.stop }
  session
end