Fix pid discovery for Unicorn in PidProvider

1 files changed, 21 insertions, 14 deletions

diff --git a/lib/prometheus/pid_provider.rb b/lib/prometheus/pid_provider.rb
index c92522c73c5..e0f7e7e0a9e 100644
--- a/lib/prometheus/pid_provider.rb
+++ b/lib/prometheus/pid_provider.rb
@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require 'prometheus/client/support/unicorn'
-
 module Prometheus
   module PidProvider
     extend self
@@ -10,29 +8,38 @@ module Prometheus
       if Sidekiq.server?
         'sidekiq'
       elsif defined?(Unicorn::Worker)
-        "unicorn_#{unicorn_worker_id}"
+        unicorn_worker_id
       elsif defined?(::Puma)
-        "puma_#{puma_worker_id}"
+        puma_worker_id
       else
-        "process_#{Process.pid}"
+        unknown_process_id
       end
     end
 
     private
 
-    # This is not fully accurate as we don't really know if the nil returned
-    # is actually means we're on master or not.
-    # Follow up issue was created to address this problem and
-    # to introduce more structrured approach to a current process discovery:
-    # https://gitlab.com/gitlab-org/gitlab-ce/issues/64740
     def unicorn_worker_id
-      ::Prometheus::Client::Support::Unicorn.worker_id || 'master'
+      if matches = process_name.match(/unicorn.*worker\[([0-9]+)\]/)
+        "unicorn_#{matches[1]}"
+      elsif process_name =~ /unicorn/
+        "unicorn_master"
+      else
+        unknown_process_id
+      end
     end
 
-    # See the comment for #unicorn_worker_id
     def puma_worker_id
-      match = process_name.match(/cluster worker ([0-9]+):/)
-      match ? match[1] : 'master'
+      if matches = process_name.match(/puma.*cluster worker ([0-9]+):/)
+        "puma_#{matches[1]}"
+      elsif process_name =~ /puma/
+        "puma_master"
+      else
+        unknown_process_id
+      end
+    end
+
+    def unknown_process_id
+      "process_#{Process.pid}"
     end
 
     def process_name