Update Metrics references to Object path

On reload, references to Metrics within classes in the Gitlab::Metrics
module fail. Update all references to ::Gitlab::Metrics so that
constant lookup finds the right module in development. This fix should
not impact production.

app/workers/reactive_caching_worker.rb

@@ -6,7 +6,7 @@ class ReactiveCachingWorker
   # rubocop: disable CodeReuse/ActiveRecord
   def perform(class_name, id, *args)
     klass = begin
-      Kernel.const_get(class_name)
+      class_name.constantize
     rescue NameError
       nil
     end

lib/gitlab/metrics/instrumentation.rb

@@ -19,7 +19,7 @@ module Gitlab
 
       # Returns the name of the series to use for storing method calls.
       def self.series
-        @series ||= "#{Metrics.series_prefix}method_calls"
+        @series ||= "#{::Gitlab::Metrics.series_prefix}method_calls"
       end
 
       # Instruments a class method.
@@ -118,7 +118,7 @@ module Gitlab
       # mod  - The module containing the method.
       # name - The name of the method to instrument.
       def self.instrument(type, mod, name)
-        return unless Metrics.enabled?
+        return unless ::Gitlab::Metrics.enabled?
 
         name = name.to_sym
         target = type == :instance ? mod : mod.singleton_class

lib/gitlab/metrics/method_call.rb

@@ -65,7 +65,7 @@ module Gitlab
       # Returns true if the total runtime of this method exceeds the method call
       # threshold.
       def above_threshold?
-        real_time.in_milliseconds >= Metrics.method_call_threshold
+        real_time.in_milliseconds >= ::Gitlab::Metrics.method_call_threshold
       end
     end
   end

lib/gitlab/metrics/methods.rb

@@ -58,11 +58,11 @@ module Gitlab
         def build_metric!(type, name, options)
           case type
           when :gauge
-            Gitlab::Metrics.gauge(name, options.docstring, options.base_labels, options.multiprocess_mode)
+            ::Gitlab::Metrics.gauge(name, options.docstring, options.base_labels, options.multiprocess_mode)
           when :counter
-            Gitlab::Metrics.counter(name, options.docstring, options.base_labels)
+            ::Gitlab::Metrics.counter(name, options.docstring, options.base_labels)
           when :histogram
-            Gitlab::Metrics.histogram(name, options.docstring, options.base_labels, options.buckets)
+            ::Gitlab::Metrics.histogram(name, options.docstring, options.base_labels, options.buckets)
           when :summary
             raise NotImplementedError, "summary metrics are not currently supported"
           else

lib/gitlab/metrics/requests_rack_middleware.rb

@@ -8,15 +8,15 @@ module Gitlab
       end
 
       def self.http_request_total
-        @http_request_total ||= Gitlab::Metrics.counter(:http_requests_total, 'Request count')
+        @http_request_total ||= ::Gitlab::Metrics.counter(:http_requests_total, 'Request count')
       end
 
       def self.rack_uncaught_errors_count
-        @rack_uncaught_errors_count ||= Gitlab::Metrics.counter(:rack_uncaught_errors_total, 'Request handling uncaught errors count')
+        @rack_uncaught_errors_count ||= ::Gitlab::Metrics.counter(:rack_uncaught_errors_total, 'Request handling uncaught errors count')
       end
 
       def self.http_request_duration_seconds
-        @http_request_duration_seconds ||= Gitlab::Metrics.histogram(:http_request_duration_seconds, 'Request handling execution time',
+        @http_request_duration_seconds ||= ::Gitlab::Metrics.histogram(:http_request_duration_seconds, 'Request handling execution time',
                                                            {}, [0.05, 0.1, 0.25, 0.5, 0.7, 1, 2.5, 5, 10, 25])
       end
 

lib/gitlab/metrics/samplers/influx_sampler.rb

@@ -10,7 +10,7 @@ module Gitlab
       # statistics, etc.
       class InfluxSampler < BaseSampler
         # interval - The sampling interval in seconds.
-        def initialize(interval = Metrics.settings[:sample_interval])
+        def initialize(interval = ::Gitlab::Metrics.settings[:sample_interval])
           super(interval)
           @last_step = nil
 
@@ -32,7 +32,7 @@ module Gitlab
         end
 
         def flush
-          Metrics.submit_metrics(@metrics.map(&:to_hash))
+          ::Gitlab::Metrics.submit_metrics(@metrics.map(&:to_hash))
         end
 
         def sample_memory_usage

lib/gitlab/metrics/samplers/ruby_sampler.rb

@@ -24,14 +24,14 @@ module Gitlab
 
         def init_metrics
           metrics = {}
-          metrics[:sampler_duration] = Metrics.counter(with_prefix(:sampler, :duration_seconds_total), 'Sampler time', labels)
-          metrics[:total_time] = Metrics.counter(with_prefix(:gc, :duration_seconds_total), 'Total GC time', labels)
+          metrics[:sampler_duration] = ::Gitlab::Metrics.counter(with_prefix(:sampler, :duration_seconds_total), 'Sampler time', labels)
+          metrics[:total_time] = ::Gitlab::Metrics.counter(with_prefix(:gc, :duration_seconds_total), 'Total GC time', labels)
           GC.stat.keys.each do |key|
-            metrics[key] = Metrics.gauge(with_prefix(:gc_stat, key), to_doc_string(key), labels, :livesum)
+            metrics[key] = ::Gitlab::Metrics.gauge(with_prefix(:gc_stat, key), to_doc_string(key), labels, :livesum)
           end
 
-          metrics[:memory_usage] = Metrics.gauge(with_prefix(:memory, :bytes), 'Memory used', labels, :livesum)
-          metrics[:file_descriptors] = Metrics.gauge(with_prefix(:file, :descriptors), 'File descriptors used', labels, :livesum)
+          metrics[:memory_usage] = ::Gitlab::Metrics.gauge(with_prefix(:memory, :bytes), 'Memory used', labels, :livesum)
+          metrics[:file_descriptors] = ::Gitlab::Metrics.gauge(with_prefix(:file, :descriptors), 'File descriptors used', labels, :livesum)
 
           metrics
         end

lib/gitlab/metrics/samplers/unicorn_sampler.rb

@@ -9,11 +9,11 @@ module Gitlab
         end
 
         def unicorn_active_connections
-          @unicorn_active_connections ||= Gitlab::Metrics.gauge(:unicorn_active_connections, 'Unicorn active connections', {}, :max)
+          @unicorn_active_connections ||= ::Gitlab::Metrics.gauge(:unicorn_active_connections, 'Unicorn active connections', {}, :max)
         end
 
         def unicorn_queued_connections
-          @unicorn_queued_connections ||= Gitlab::Metrics.gauge(:unicorn_queued_connections, 'Unicorn queued connections', {}, :max)
+          @unicorn_queued_connections ||= ::Gitlab::Metrics.gauge(:unicorn_queued_connections, 'Unicorn queued connections', {}, :max)
         end
 
         def enabled?

lib/gitlab/metrics/sidekiq_metrics_exporter.rb

@@ -9,7 +9,7 @@ module Gitlab
       LOG_FILENAME = File.join(Rails.root, 'log', 'sidekiq_exporter.log')
 
       def enabled?
-        Gitlab::Metrics.metrics_folder_present? && settings.enabled
+        ::Gitlab::Metrics.metrics_folder_present? && settings.enabled
       end
 
       def settings

lib/gitlab/metrics/subscribers/rails_cache.rb

@@ -64,7 +64,7 @@ module Gitlab
         end
 
         def metric_cache_operation_duration_seconds
-          @metric_cache_operation_duration_seconds ||= Gitlab::Metrics.histogram(
+          @metric_cache_operation_duration_seconds ||= ::Gitlab::Metrics.histogram(
             :gitlab_cache_operation_duration_seconds,
             'Cache access time',
             Transaction::BASE_LABELS.merge({ action: nil }),
@@ -73,7 +73,7 @@ module Gitlab
         end
 
         def metric_cache_misses_total
-          @metric_cache_misses_total ||= Gitlab::Metrics.counter(
+          @metric_cache_misses_total ||= ::Gitlab::Metrics.counter(
             :gitlab_cache_misses_total,
             'Cache read miss',
             Transaction::BASE_LABELS

lib/gitlab/metrics/transaction.rb

@@ -64,7 +64,7 @@ module Gitlab
       end
 
       def add_metric(series, values, tags = {})
-        @metrics << Metric.new("#{Metrics.series_prefix}#{series}", values, tags)
+        @metrics << Metric.new("#{::Gitlab::Metrics.series_prefix}#{series}", values, tags)
       end
 
       # Tracks a business level event
@@ -127,7 +127,7 @@ module Gitlab
           hash
         end
 
-        Metrics.submit_metrics(submit_hashes)
+        ::Gitlab::Metrics.submit_metrics(submit_hashes)
       end
 
       def labels