Expose a clean_backtrace method from Gitlab::Profiler

This method makes it easier for other parts of the app to get clean backtraces,
as well as console users.

lib/gitlab/profiler.rb

@@ -11,6 +11,7 @@ module Gitlab
       lib/gitlab/etag_caching/
       lib/gitlab/metrics/
       lib/gitlab/middleware/
+      ee/lib/gitlab/middleware/
       lib/gitlab/performance_bar/
       lib/gitlab/request_profiler/
       lib/gitlab/profiler.rb
@@ -98,11 +99,7 @@ module Gitlab
 
             super
 
-            backtrace = Rails.backtrace_cleaner.clean(caller)
-
-            backtrace.each do |caller_line|
-              next if caller_line.match(Regexp.union(IGNORE_BACKTRACES))
-
+            Gitlab::Profiler.clean_backtrace(caller).each do |caller_line|
               stripped_caller_line = caller_line.sub("#{Rails.root}/", '')
 
               super("  ↳ #{stripped_caller_line}")
@@ -112,6 +109,12 @@ module Gitlab
       end
     end
 
+    def self.clean_backtrace(backtrace)
+      Array(Rails.backtrace_cleaner.clean(backtrace)).reject do |line|
+        line.match(Regexp.union(IGNORE_BACKTRACES))
+      end
+    end
+
     def self.with_custom_logger(logger)
       original_colorize_logging = ActiveSupport::LogSubscriber.colorize_logging
       original_activerecord_logger = ActiveRecord::Base.logger

spec/lib/gitlab/profiler_spec.rb

@@ -135,6 +135,51 @@ describe Gitlab::Profiler do
     end
   end
 
+  describe '.clean_backtrace' do
+    it 'uses the Rails backtrace cleaner' do
+      backtrace = []
+
+      expect(Rails.backtrace_cleaner).to receive(:clean).with(backtrace)
+
+      described_class.clean_backtrace(backtrace)
+    end
+
+    it 'removes lines from IGNORE_BACKTRACES' do
+      backtrace = [
+        "lib/gitlab/gitaly_client.rb:294:in `block (2 levels) in migrate'",
+        "lib/gitlab/gitaly_client.rb:331:in `allow_n_plus_1_calls'",
+        "lib/gitlab/gitaly_client.rb:280:in `block in migrate'",
+        "lib/gitlab/metrics/influx_db.rb:103:in `measure'",
+        "lib/gitlab/gitaly_client.rb:278:in `migrate'",
+        "lib/gitlab/git/repository.rb:1451:in `gitaly_migrate'",
+        "lib/gitlab/git/commit.rb:66:in `find'",
+        "app/models/repository.rb:1047:in `find_commit'",
+        "lib/gitlab/metrics/instrumentation.rb:159:in `block in find_commit'",
+        "lib/gitlab/metrics/method_call.rb:36:in `measure'",
+        "lib/gitlab/metrics/instrumentation.rb:159:in `find_commit'",
+        "app/models/repository.rb:113:in `commit'",
+        "lib/gitlab/i18n.rb:50:in `with_locale'",
+        "lib/gitlab/middleware/multipart.rb:95:in `call'",
+        "lib/gitlab/request_profiler/middleware.rb:14:in `call'",
+        "ee/lib/gitlab/database/load_balancing/rack_middleware.rb:37:in `call'",
+        "ee/lib/gitlab/jira/middleware.rb:15:in `call'"
+      ]
+
+      expect(described_class.clean_backtrace(backtrace))
+        .to eq([
+                 "lib/gitlab/gitaly_client.rb:294:in `block (2 levels) in migrate'",
+                 "lib/gitlab/gitaly_client.rb:331:in `allow_n_plus_1_calls'",
+                 "lib/gitlab/gitaly_client.rb:280:in `block in migrate'",
+                 "lib/gitlab/gitaly_client.rb:278:in `migrate'",
+                 "lib/gitlab/git/repository.rb:1451:in `gitaly_migrate'",
+                 "lib/gitlab/git/commit.rb:66:in `find'",
+                 "app/models/repository.rb:1047:in `find_commit'",
+                 "app/models/repository.rb:113:in `commit'",
+                 "ee/lib/gitlab/jira/middleware.rb:15:in `call'"
+               ])
+    end
+  end
+
   describe '.with_custom_logger' do
     context 'when the logger is set' do
       it 'uses the replacement logger for the duration of the block' do