refactor git access spec, update docs

doc/gitlab-geo/using_a_geo_server.md

+[//]: # (Please update EE::GitLab::GeoGitAccess::GEO_SERVER_DOCS_URL if this file is moved)
+
 # Using a Geo Server
 
 After you set up the [database replication and configure the GitLab Geo nodes][req],

ee/lib/ee/gitlab/git_access.rb

 module EE
   module Gitlab
     module GitAccess
-      GEO_SERVER_DOCS_URL = 'https://docs.gitlab.com/ee/gitlab-geo/using_a_geo_server.html'.freeze
+      prepend GeoGitAccess
 
       def check(cmd, changes)
         raise NotImplementedError.new unless defined?(super)
@@ -65,17 +65,6 @@ module EE
       def geo?
         geo_node_key? || actor == :geo
       end
-
-      def push_to_read_only_message
-        message = super
-
-        if ::Gitlab::Geo.primary_node
-          primary_url = ActionController::Base.helpers.link_to('primary node', ::Gitlab::Geo.primary_node.url)
-          message += " Please use the Primary node URL: #{primary_url.html_safe}. Documentation: #{GEO_SERVER_DOCS_URL}"
-        end
-
-        message
-      end
     end
   end
 end

spec/ee/spec/lib/ee/gitlab/git_access_spec.rb

@@ -10,7 +10,7 @@ describe Gitlab::GitAccess do
   let(:redirected_path) { nil }
 
   let(:access) { described_class.new(actor, project, protocol, authentication_abilities: authentication_abilities, redirected_path: redirected_path) }
-  let(:push_access_check) { access.check('git-receive-pack', '_any') }
+  subject { access.check('git-receive-pack', '_any') }
 
   context "when in a read-only GitLab instance" do
     before do
@@ -21,7 +21,7 @@ describe Gitlab::GitAccess do
     it 'denies push access' do
       project.add_master(user)
 
-      expect { push_access_check }.to raise_unauthorized("You can't push code to a read-only GitLab instance.")
+      expect { subject }.to raise_unauthorized("You can't push code to a read-only GitLab instance.")
     end
 
     it 'denies push access with primary present' do
@@ -33,7 +33,7 @@ describe Gitlab::GitAccess do
 
       project.add_master(user)
 
-      expect { push_access_check }.to raise_unauthorized(error_message)
+      expect { subject }.to raise_unauthorized(error_message)
     end
   end