Gather memory usage data in tests

Log memory stats after running each spec file and compile the report.

2 files changed, 59 insertions, 0 deletions

diff --git a/spec/support/helpers/memory_usage_helper.rb b/spec/support/helpers/memory_usage_helper.rb
new file mode 100644
index 00000000000..984ea8cc571
--- /dev/null
+++ b/spec/support/helpers/memory_usage_helper.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module MemoryUsageHelper
+  extend ActiveSupport::Concern
+
+  def gather_memory_data(csv_path)
+    write_csv_entry(csv_path,
+      {
+        example_group_path: TestEnv.topmost_example_group[:location],
+        example_group_description: TestEnv.topmost_example_group[:description],
+        time: Time.current,
+        job_name: ENV['CI_JOB_NAME']
+      }.merge(get_memory_usage))
+  end
+
+  def write_csv_entry(path, entry)
+    CSV.open(path, "a", headers: entry.keys, write_headers: !File.exist?(path)) do |file|
+      file << entry.values
+    end
+  end
+
+  def get_memory_usage
+    output, status = Gitlab::Popen.popen(%w(free -m))
+    abort "`free -m` return code is #{status}: #{output}" unless status.zero?
+
+    result = output.split("\n")[1].split(" ")[1..-1]
+    attrs = %i(m_total m_used m_free m_shared m_buffers_cache m_available).freeze
+
+    attrs.zip(result).to_h
+  end
+
+  included do |config|
+    config.after(:all) do
+      gather_memory_data(ENV['MEMORY_TEST_PATH']) if ENV['MEMORY_TEST_PATH']
+    end
+  end
+end
diff --git a/spec/support/helpers/test_env.rb b/spec/support/helpers/test_env.rb
index e63099d89b7..893b10ea752 100644
--- a/spec/support/helpers/test_env.rb
+++ b/spec/support/helpers/test_env.rb
@@ -2,6 +2,7 @@ require 'rspec/mocks'
 require 'toml-rb'
 
 module TestEnv
+  extend ActiveSupport::Concern
   extend self
 
   ComponentFailedToInstallError = Class.new(StandardError)
@@ -108,6 +109,12 @@ module TestEnv
     setup_forked_repo
   end
 
+  included do |config|
+    config.append_before do
+      set_current_example_group
+    end
+  end
+
   def disable_mailer
     allow_any_instance_of(NotificationService).to receive(:mailer)
       .and_return(double.as_null_object)
@@ -297,8 +304,23 @@ module TestEnv
     FileUtils.rm_rf(path)
   end
 
+  def current_example_group
+    Thread.current[:current_example_group]
+  end
+
+  # looking for a top-level `describe`
+  def topmost_example_group
+    example_group = current_example_group
+    example_group = example_group[:parent_example_group] until example_group[:parent_example_group].nil?
+    example_group
+  end
+
   private
 
+  def set_current_example_group
+    Thread.current[:current_example_group] = ::RSpec.current_example.metadata[:example_group]
+  end
+
   # These are directories that should be preserved at cleanup time
   def test_dirs
     @test_dirs ||= %w[