Add custom root links (#4307)

Author: Samze

app/controllers/runtime/root_controller.rb

@@ -60,12 +60,13 @@ def read
               oauth_client: config.get(:info, :app_ssh_oauth_client)
             }
           }
-
         }
       }
 
       response[:links].merge!(cloud_controller_v2(api_url_builder)) if config.get(:temporary_enable_v2)
 
+      response[:links].merge!(custom_links(config.get(:custom_root_links))) if config.get(:custom_root_links)
+
       [200, Oj.dump(response, mode: :compat)]
     end
 
@@ -98,5 +99,14 @@ def cloud_controller_v2(api_url_builder)
           }
       }
     end
+
+    def custom_links(links)
+      result = {}
+      links.each do |value|
+        value = ActiveSupport::HashWithIndifferentAccess.new(value)
+        result[value['name']] = { href: value['href'] }
+      end
+      result
+    end
   end
 end

lib/cloud_controller/config_schemas/base/api_schema.rb

@@ -30,6 +30,7 @@ class ApiSchema < VCAP::Config
               optional(:app_ssh_host_key_fingerprint) => String,
               optional(:custom) => Hash
             },
+            optional(:custom_root_links) => Array,
 
             system_domain: String,
             optional(:system_domain_organization) => enum(String, NilClass),

spec/unit/controllers/runtime/root_controller_spec.rb

@@ -174,6 +174,27 @@ module VCAP::CloudController
           }
         )
       end
+
+      describe 'custom links' do
+        context 'custom links are configured' do
+          it 'returns a link' do
+            TestConfig.override(custom_root_links: [{ name: 'custom_link_1', href: 'custom_link_1.com' }, { name: 'custom_link_2', href: 'custom_link_2.com' }])
+            get '/'
+            hash = Oj.load(last_response.body)
+            expect(hash['links']['custom_link_1']['href']).to eq('custom_link_1.com')
+            expect(hash['links']['custom_link_2']['href']).to eq('custom_link_2.com')
+          end
+        end
+
+        context 'custom links overrides an existing link' do
+          it 'returns the custom link' do
+            TestConfig.override(custom_root_links: [{ name: 'uaa', href: 'my_new_uaa.com' }])
+            get '/'
+            hash = Oj.load(last_response.body)
+            expect(hash['links']['uaa']['href']).to eq('my_new_uaa.com')
+          end
+        end
+      end
     end
   end
 end