Fix Peek on Puma

Peek's `Peek.request_id` method doesn't work well with a multi-threaded
server and concurrent requests, because requests can 'steal' another
request's ID, or unset it before it was due.

The upstream change resolves this; the commit here is just to ensure
that GitLab works with that upstream change, mostly by not using
`Peek.request_id` any more (as the method doesn't exist).

Gemfile

@@ -295,7 +295,7 @@ gem 'gettext', '~> 3.2.2', require: false, group: :development
 gem 'batch-loader', '~> 1.4.0'
 # Perf bar
-gem 'peek', '~> 1.0.1'
+gem 'peek', git: 'https://github.com/smcgivern/peek', branch: 'remove-peek-request-id'
 # Snowplow events tracking
 gem 'snowplow-tracker', '~> 0.6.1'

Gemfile.lock

+GIT
+  remote: https://github.com/smcgivern/peek
+  revision: b7164ce54b63670f5406f4dc3cb3f5594d71bfaa
+  branch: remove-peek-request-id
+  specs:
+    peek (1.0.1)
+      railties (>= 4.0.0)
+
 GEM
   remote: https://rubygems.org/
   specs:
@@ -147,8 +155,6 @@ GEM
       adamantium (~> 0.2.0)
       equalizer (~> 0.0.9)
     concurrent-ruby (1.1.5)
-    concurrent-ruby-ext (1.1.5)
-      concurrent-ruby (= 1.1.5)
     connection_pool (2.2.2)
     contracts (0.11.0)
     crack (0.4.3)
@@ -640,10 +646,6 @@ GEM
     parser (2.6.3.0)
       ast (~> 2.4.0)
     parslet (1.8.2)
-    peek (1.0.1)
-      concurrent-ruby (>= 0.9.0)
-      concurrent-ruby-ext (>= 0.9.0)
-      railties (>= 4.0.0)
     pg (1.1.4)
     po_to_json (1.0.1)
       json (>= 1.6.0)
@@ -1177,7 +1179,7 @@ DEPENDENCIES
   omniauth_crowd (~> 2.2.0)
   omniauth_openid_connect (~> 0.3.1)
   org-ruby (~> 0.9.12)
-  peek (~> 1.0.1)
+  peek!
   pg (~> 1.1)
   premailer-rails (~> 1.9.7)
   prometheus-client-mmap (~> 0.9.8)

app/controllers/concerns/with_performance_bar.rb

@@ -3,6 +3,12 @@
 module WithPerformanceBar
   extend ActiveSupport::Concern
+  included do
+    before_action :peek_enabled? # Warm cache
+  end
+
+  protected
+
   def peek_enabled?
     return false unless Gitlab::PerformanceBar.enabled?(current_user)

app/views/peek/_bar.html.haml

 - return unless peek_enabled?
 #js-peek{ data: { env: Peek.env,
-         request_id: Peek.request_id,
+         request_id: peek_request_id,
          peek_url: "#{peek_routes_path}/results" },
          class: Peek.env }

changelogs/unreleased/fix-peek-on-puma.yml

+---
+title: Fix performance bar on Puma
+merge_request: 32213
+author:
+type: fixed

lib/gitlab/performance_bar/redis_adapter_when_peek_enabled.rb

@@ -4,8 +4,8 @@
 module Gitlab
   module PerformanceBar
     module RedisAdapterWhenPeekEnabled
-      def save
-        super unless ::Peek.request_id.blank?
+      def save(request_id)
+        super if ::Peek.enabled? && request_id.present?
       end
     end
   end