Fixes #31715 - print slow initializers to debug log

config/initializers/0_print_time_spent.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+# This class is taken from https://github.com/nevir/Bumbler which
+# depends on bundler. But for RPM environment, Foreman does not
+# use bundler (but bundler_ext stub). The gem won't load in that
+# environment.
+module ForemanInitializers
+  @slow_threshold = 100.0
+  @slow_items = {}
+
+  class << self
+    attr_writer :slow_threshold
+    attr_reader :slow_items
+
+    def benchmark(key)
+      start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      result = yield
+      time = (Process.clock_gettime(Process::CLOCK_MONOTONIC) - start) * 1000 # ms
+      @slow_items[key] = time if time > @slow_threshold
+      result
+    end
+
+    def print_slow_items
+      if slow_items.any?
+        Rails.logger.debug "Slow initializers:"
+        slow_items.sort_by { |k, v| v }.each do |name, time|
+          Rails.logger.debug format('  %s  %s', ('%.2f' % time).rjust(8), name)
+        end
+      end
+      self
+    end
+  end
+end
+
+Rails::Engine.prepend(Module.new do
+  def load(file, *)
+    initializer = file.sub(Rails.root.to_s, ".")
+    ForemanInitializers.benchmark(initializer) { super }
+  end
+end)
+
+Rails::Initializable::Initializer.prepend(Module.new do
+  def run(*)
+    name = (@name.is_a?(Symbol) ? @name.inspect : @name)
+    ForemanInitializers.benchmark(name) { super }
+  end
+end)

config/initializers/z_print_slow_initializers.rb

@@ -0,0 +1 @@
+ForemanInitializers.print_slow_items