Create idea of read-only database

In GitLab EE, a GitLab instance can be read-only (e.g. when it's a Geo
secondary node). But in GitLab CE it also might be useful to have the
"read-only" idea around. So port it back to GitLab CE.

Also having the principle of read-only in GitLab CE would hopefully
lead to less errors introduced, doing write operations when there
aren't allowed for read-only calls.

Closes gitlab-org/gitlab-ce#37534.

1 files changed, 22 insertions, 15 deletions

diff --git a/app/controllers/sessions_controller.rb b/app/controllers/sessions_controller.rb
index ada91694fd6..c01be42c3ee 100644
--- a/app/controllers/sessions_controller.rb
+++ b/app/controllers/sessions_controller.rb
@@ -8,8 +8,7 @@ class SessionsController < Devise::SessionsController
   prepend_before_action :check_initial_setup, only: [:new]
   prepend_before_action :authenticate_with_two_factor,
     if: :two_factor_enabled?, only: [:create]
-  prepend_before_action :store_redirect_path, only: [:new]
-
+  prepend_before_action :store_redirect_uri, only: [:new]
   before_action :auto_sign_in_with_provider, only: [:new]
   before_action :load_recaptcha
 
@@ -86,28 +85,36 @@ class SessionsController < Devise::SessionsController
     end
   end
 
-  def store_redirect_path
-    redirect_path =
+  def stored_redirect_uri
+    @redirect_to ||= stored_location_for(:redirect)
+  end
+
+  def store_redirect_uri
+    redirect_uri =
       if request.referer.present? && (params['redirect_to_referer'] == 'yes')
-        referer_uri = URI(request.referer)
-        if referer_uri.host == Gitlab.config.gitlab.host
-          referer_uri.request_uri
-        else
-          request.fullpath
-        end
+        URI(request.referer)
       else
-        request.fullpath
+        URI(request.url)
       end
 
     # Prevent a 'you are already signed in' message directly after signing:
     # we should never redirect to '/users/sign_in' after signing in successfully.
-    unless URI(redirect_path).path == new_user_session_path
-      store_location_for(:redirect, redirect_path)
-    end
+    return true if redirect_uri.path == new_user_session_path
+
+    redirect_to = redirect_uri.to_s if redirect_allowed_to?(redirect_uri)
+
+    @redirect_to = redirect_to
+    store_location_for(:redirect, redirect_to)
+  end
+
+  # Overridden in EE
+  def redirect_allowed_to?(uri)
+    uri.host == Gitlab.config.gitlab.host &&
+      uri.port == Gitlab.config.gitlab.port
   end
 
   def two_factor_enabled?
-    find_user.try(:two_factor_enabled?)
+    find_user&.two_factor_enabled?
   end
 
   def auto_sign_in_with_provider