Fix bug with monotonic_time, updates for style in tests

Per feedback on MR

ee/lib/gitlab/sidekiq_cluster/cli.rb

@@ -68,17 +68,21 @@ module Gitlab
         SidekiqCluster.write_pid(@pid) if @pid
       end
 
+      def monotonic_time
+        Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_second)
+      end
+
       def continue_waiting?(deadline)
-        SidekiqCluster.any_alive?(@processes) && Gitlab::Metrics::System.monotonic_time < deadline
+        SidekiqCluster.any_alive?(@processes) && monotonic_time < deadline
       end
 
       def hard_stop_stuck_pids
         SidekiqCluster.signal_processes(SidekiqCluster.pids_alive(@processes), :KILL)
       end
 
-      def wait_for_termination(check_interval = CHECK_TERMINATE_INTERVAL_SECONDS, terminate_timeout = TERMINATE_TIMEOUT_SECONDS)
-        deadline = Gitlab::Metrics::System.monotonic_time + terminate_timeout
-        sleep(check_interval) while continue_waiting?(deadline)
+      def wait_for_termination
+        deadline = monotonic_time + TERMINATE_TIMEOUT_SECONDS
+        sleep(CHECK_TERMINATE_INTERVAL_SECONDS) while continue_waiting?(deadline)
 
         hard_stop_stuck_pids
       end

ee/spec/lib/gitlab/sidekiq_cluster/cli_spec.rb

@@ -95,8 +95,9 @@ describe Gitlab::SidekiqCluster::CLI do
       expect(Gitlab::SidekiqCluster).to receive(:signal_processes)
         .with([], :KILL)
 
-      # Check every 0.1s, for no more than 1 second total
-      cli.wait_for_termination(0.1, 1)
+      stub_const("Gitlab::SidekiqCluster::CLI::CHECK_TERMINATE_INTERVAL_SECONDS", 0.1)
+      stub_const("Gitlab::SidekiqCluster::CLI::TERMINATE_TIMEOUT_SECONDS", 1)
+      cli.wait_for_termination
     end
 
     context 'with hanging workers' do
@@ -123,8 +124,9 @@ describe Gitlab::SidekiqCluster::CLI do
 
         cli.run(%w(foo))
 
-        # Check every 0.1s, for no more than 1 second total
-        cli.wait_for_termination(0.1, 1)
+        stub_const("Gitlab::SidekiqCluster::CLI::CHECK_TERMINATE_INTERVAL_SECONDS", 0.1)
+        stub_const("Gitlab::SidekiqCluster::CLI::TERMINATE_TIMEOUT_SECONDS", 1)
+        cli.wait_for_termination
       end
     end
   end