gitlab-org--gitlab-foss/metrics_server/metrics_server.rb

65 lines
2.1 KiB
Ruby

# frozen_string_literal: true
require_relative '../config/boot'
require_relative 'dependencies'
class MetricsServer # rubocop:disable Gitlab/NamespacedClass
class << self
def spawn(target, metrics_dir:, wipe_metrics_dir: false, trapped_signals: [])
raise "The only valid target is 'sidekiq' currently" unless target == 'sidekiq'
pid = Process.fork
if pid.nil? # nil means we're inside the fork
# Remove any custom signal handlers the parent process had registered, since we do
# not want to inherit them, and Ruby forks with a `clone` that has the `CLONE_SIGHAND`
# flag set.
Gitlab::ProcessManagement.modify_signals(trapped_signals, 'DEFAULT')
server = MetricsServer.new(target, metrics_dir, wipe_metrics_dir)
# This rewrites /proc/cmdline, since otherwise tools like `top` will show the
# parent process `cmdline` which is really confusing.
$0 = server.name
server.start
else
Process.detach(pid)
end
pid
end
end
def initialize(target, metrics_dir, wipe_metrics_dir)
@target = target
@metrics_dir = metrics_dir
@wipe_metrics_dir = wipe_metrics_dir
end
def start
::Prometheus::Client.configure do |config|
config.multiprocess_files_dir = @metrics_dir
config.pid_provider = proc { "#{@target}_exporter" }
end
FileUtils.mkdir_p(@metrics_dir, mode: 0700)
::Prometheus::CleanupMultiprocDirService.new.execute if @wipe_metrics_dir
# We need to `warmup: true` since otherwise the sampler and exporter threads enter
# a race where not all Prometheus db files will be visible to the exporter, resulting
# in missing metrics.
# Warming up ensures that these files exist prior to the exporter starting up.
Gitlab::Metrics::Samplers::RubySampler.initialize_instance(warmup: true).start
exporter_class = "Gitlab::Metrics::Exporter::#{@target.camelize}Exporter".constantize
settings = Settings.new(Settings.monitoring[name])
server = exporter_class.instance(settings, synchronous: true)
server.start
end
def name
"#{@target}_exporter"
end
end