From 416076610e7b1674669ad33bae604155f55a3d02 Mon Sep 17 00:00:00 2001
From: Grzegorz Bizon <grzesiek.bizon@gmail.com>
Date: Tue, 17 Jul 2018 14:50:04 +0200
Subject: [PATCH] Implement scaffold of authentication activity metrics

---
 config/initializers/warden.rb         | 12 +++++
 lib/gitlab/auth/activity.rb           | 69 +++++++++++++++++++++++++++
 spec/lib/gitlab/auth/activity_spec.rb | 11 +++++
 3 files changed, 92 insertions(+)
 create mode 100644 lib/gitlab/auth/activity.rb
 create mode 100644 spec/lib/gitlab/auth/activity_spec.rb

diff --git a/config/initializers/warden.rb b/config/initializers/warden.rb
index 8cc36820d3c..c75a76a3118 100644
--- a/config/initializers/warden.rb
+++ b/config/initializers/warden.rb
@@ -5,17 +5,29 @@ Rails.application.configure do |config|
 
   Warden::Manager.before_failure(scope: :user) do |env, opts|
     Gitlab::Auth::BlockedUserTracker.log_if_user_blocked(env)
+
+    Gitlab::Auth::Activity.new(opts).user_authentication_failed!
   end
 
   Warden::Manager.after_authentication(scope: :user) do |user, auth, opts|
     ActiveSession.cleanup(user)
+
+    Gitlab::Auth::Activity.new(opts).user_authenticated!
   end
 
   Warden::Manager.after_set_user(scope: :user, only: :fetch) do |user, auth, opts|
     ActiveSession.set(user, auth.request)
+
+    Gitlab::Auth::Activity.new(opts).user_session_fetched!
+  end
+
+  Warden::Manager.after_set_user(scope: :user, only: :set_user) do |user, auth, opts|
+    Gitlab::Auth::Activity.new(opts).user_set_manually!
   end
 
   Warden::Manager.before_logout(scope: :user) do |user, auth, opts|
     ActiveSession.destroy(user || auth.user, auth.request.session.id)
+
+    Gitlab::Auth::Activity.new(opts).user_logout!
   end
 end
diff --git a/lib/gitlab/auth/activity.rb b/lib/gitlab/auth/activity.rb
new file mode 100644
index 00000000000..c0254ca81cd
--- /dev/null
+++ b/lib/gitlab/auth/activity.rb
@@ -0,0 +1,69 @@
+module Gitlab
+  module Auth
+    ##
+    # Metrics and logging for user authentication activity.
+    #
+    class Activity
+      extend Gitlab::Utils::StrongMemoize
+
+      COUNTERS = {
+        user_authenticated: 'Counter of total successful authentication events',
+        user_unauthenticated: 'Counter of total authentication failures',
+        user_not_found: 'Counter of total failed log-ins when user is unknown',
+        user_password_invalid: 'Counter of failed log-ins with invalid password',
+        user_session_fetched: 'Counter of total sessions fetched',
+        user_session_override: 'Counter of manual log-ins and sessions overrides',
+        user_signed_out: 'Counter of total user sign out events'
+      }.freeze
+
+      def initialize(opts)
+        @opts = opts
+      end
+
+      def user_authentication_failed!
+        self.class.user_unauthenticated_counter.increment
+
+        case @opts[:message]
+        when :not_found_in_database
+          self.class.user_not_found_counter.increment
+        when :invalid
+          self.class.user_password_invalid_counter.increment
+        end
+      end
+
+      def user_authenticated!
+        self.class.user_authenticated_counter.increment
+      end
+
+      def user_session_fetched!
+        self.class.user_session_fetched_counter.increment
+      end
+
+      def user_set_manually!
+        self.class.user_session_override_counter.increment
+      end
+
+      def user_logout!
+        self.class.user_signed_out_counter.increment
+      end
+
+      class StubCounter
+        def initialize(metric)
+          Rails.logger.warn("METRIC #{metric}")
+        end
+
+        def increment
+        end
+      end
+
+      COUNTERS.each_pair do |metric, description|
+        define_singleton_method("#{metric}_counter") do
+          strong_memoize(metric) do
+            StubCounter.new(metric)
+            # Gitlab::Metrics.counter("gitlab_auth_#{metric}_total", description)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/auth/activity_spec.rb b/spec/lib/gitlab/auth/activity_spec.rb
new file mode 100644
index 00000000000..311c29010b3
--- /dev/null
+++ b/spec/lib/gitlab/auth/activity_spec.rb
@@ -0,0 +1,11 @@
+require 'spec_helper'
+
+describe Gitlab::Auth::Activity do
+  describe 'counters' do
+    it 'has all static counters defined' do
+      described_class::COUNTERS.each_key do |metric|
+        expect(described_class).to respond_to("#{metric}_counter")
+      end
+    end
+  end
+end