Improve runtime identification errors

- don't allow `:unknown` runtime, raise error instead
- log errors to Sentry in initializer

config/initializers/0_runtime_identify.rb

 # frozen_string_literal: true
 
 begin
-  Gitlab::AppLogger.info("Runtime: #{Gitlab::Runtime.name}")
+  current_runtime = Gitlab::Runtime.identify
+  Gitlab::AppLogger.info("Process #{Process.pid} (#{$0}) identified as: #{current_runtime}")
 rescue => e
   message = <<-NOTICE
   \n!! RUNTIME IDENTIFICATION FAILED: #{e}
@@ -10,4 +11,5 @@ rescue => e
   https://gitlab.com/gitlab-org/gitlab/issues/new
   NOTICE
   Gitlab::AppLogger.error(message)
+  Gitlab::ErrorTracking.track_exception(e)
 end

lib/gitlab/runtime.rb

@@ -4,17 +4,28 @@ module Gitlab
   # Provides routines to identify the current runtime as which the application
   # executes, such as whether it is an application server and which one.
   module Runtime
+    AmbiguousProcessError = Class.new(StandardError)
+    UnknownProcessError = Class.new(StandardError)
+
     class << self
-      def name
+      def identify
         matches = []
         matches << :puma if puma?
         matches << :unicorn if unicorn?
         matches << :console if console?
         matches << :sidekiq if sidekiq?
 
-        raise "Ambiguous process match: #{matches}" if matches.size > 1
-
-        matches.first || :unknown
+        if matches.one?
+          matches.first
+        elsif matches.none?
+          raise UnknownProcessError.new(
+            "Failed to identify runtime for process #{Process.pid} (#{$0})"
+          )
+        else
+          raise AmbiguousProcessError.new(
+            "Ambiguous runtime #{matches} for process #{Process.pid} (#{$0})"
+          )
+        end
       end
 
       def puma?

spec/lib/gitlab/runtime_spec.rb

@@ -4,8 +4,8 @@ require 'spec_helper'
 
 describe Gitlab::Runtime do
   context "when unknown" do
-    it "identifies as :unknown" do
-      expect(subject.name).to eq(:unknown)
+    it "raises an exception when trying to identify" do
+      expect { subject.identify }.to raise_error(subject::UnknownProcessError)
     end
   end
 
@@ -16,7 +16,7 @@ describe Gitlab::Runtime do
     end
 
     it "raises an exception when trying to identify" do
-      expect { subject.name }.to raise_error(RuntimeError, "Ambiguous process match: [:puma, :console]")
+      expect { subject.identify }.to raise_error(subject::AmbiguousProcessError)
     end
   end
 
@@ -28,7 +28,7 @@ describe Gitlab::Runtime do
     end
 
     it "identifies itself" do
-      expect(subject.name).to eq(:puma)
+      expect(subject.identify).to eq(:puma)
       expect(subject.puma?).to be(true)
     end
 
@@ -47,7 +47,7 @@ describe Gitlab::Runtime do
     end
 
     it "identifies itself" do
-      expect(subject.name).to eq(:unicorn)
+      expect(subject.identify).to eq(:unicorn)
       expect(subject.unicorn?).to be(true)
     end
 
@@ -67,7 +67,7 @@ describe Gitlab::Runtime do
     end
 
     it "identifies itself" do
-      expect(subject.name).to eq(:sidekiq)
+      expect(subject.identify).to eq(:sidekiq)
       expect(subject.sidekiq?).to be(true)
     end
 
@@ -86,7 +86,7 @@ describe Gitlab::Runtime do
     end
 
     it "identifies itself" do
-      expect(subject.name).to eq(:console)
+      expect(subject.identify).to eq(:console)
       expect(subject.console?).to be(true)
     end