Adapt system env presenter

When the app feature 'file-based service bindings' is enabled,
SERVICE_BINDING_ROOT is returned instead of VCAP_SERVICES.

For an app using file-based service bindings the '/env' endpoint (i.e.
GET /v3/apps/:guid/env) returns the following:

  {
    ...
    "system_env_json": {
      "SERVICE_BINDING_ROOT": "/etc/cf-service-bindings"
    },
    ...
  }

The file runtime_environment/system_env_presenter_spec.rb has been
deleted because all the tests it contained are also present in
system_environment/system_env_presenter_spec.rb.

Author: philippthun

app/controllers/runtime/apps_controller.rb

@@ -72,7 +72,7 @@ def read_env(guid)
                   staging_env_json: EnvironmentVariableGroup.staging.environment_json,
                   running_env_json: EnvironmentVariableGroup.running.environment_json,
                   environment_json: process.app.environment_variables,
-                  system_env_json: SystemEnvPresenter.new(process.service_bindings).system_env,
+                  system_env_json: SystemEnvPresenter.new(process).system_env,
                   application_env_json: { 'VCAP_APPLICATION' => vcap_application }
                 }, mode: :compat)
       ]

app/models/runtime/process_model.rb

@@ -177,6 +177,8 @@ def revisions_enabled?
       app.revisions_enabled
     end
 
+    delegate :file_based_service_bindings_enabled, to: :app
+
     def package_hash
       # this caches latest_package for performance reasons
       package = latest_package

app/presenters/system_environment/system_env_presenter.rb

@@ -2,11 +2,14 @@
 require 'presenters/system_environment/service_binding_presenter'
 
 class SystemEnvPresenter
-  def initialize(service_bindings)
-    @service_bindings = service_bindings
+  def initialize(app_or_process)
+    @file_based_service_bindings_enabled = app_or_process.file_based_service_bindings_enabled
+    @service_bindings = app_or_process.service_bindings
   end
 
   def system_env
+    return { SERVICE_BINDING_ROOT: '/etc/cf-service-bindings' } if @file_based_service_bindings_enabled
+
     { VCAP_SERVICES: service_binding_env_variables }
   end
 

app/presenters/v3/app_env_presenter.rb

@@ -25,7 +25,7 @@ def to_hash
             environment_variables: app.environment_variables,
             staging_env_json: EnvironmentVariableGroup.staging.environment_json,
             running_env_json: EnvironmentVariableGroup.running.environment_json,
-            system_env_json: redact_hash(SystemEnvPresenter.new(app.service_bindings).system_env),
+            system_env_json: redact_hash(SystemEnvPresenter.new(app).system_env),
             application_env_json: vcap_application
           }
         end

lib/cloud_controller/backends/staging_environment_builder.rb

@@ -27,7 +27,7 @@ def build(app, space, lifecycle, memory_limit, staging_disk_in_mb, vars_from_mes
             'MEMORY_LIMIT' => "#{memory_limit}m"
           }
         ).
-        merge(SystemEnvPresenter.new(app.service_bindings).system_env.stringify_keys)
+        merge(SystemEnvPresenter.new(app).system_env.stringify_keys)
     end
   end
 end

lib/cloud_controller/diego/environment.rb

@@ -41,7 +41,7 @@ def common_json_and_merge(&blk)
           @initial_env.
           merge(process.environment_json || {}).
           merge(blk.call).
-          merge(SystemEnvPresenter.new(process.service_bindings).system_env)
+          merge(SystemEnvPresenter.new(process).system_env)
 
         diego_env = diego_env.merge(DATABASE_URL: process.database_uri) if process.database_uri
 

lib/cloud_controller/diego/task_environment.rb

@@ -19,7 +19,7 @@ def build
           initial_envs.
           merge(app_env).
           merge('VCAP_APPLICATION' => vcap_application, 'MEMORY_LIMIT' => "#{task.memory_in_mb}m").
-          merge(SystemEnvPresenter.new(app.service_bindings).system_env.stringify_keys)
+          merge(SystemEnvPresenter.new(app).system_env.stringify_keys)
 
         task_env = task_env.merge('VCAP_PLATFORM_OPTIONS' => credhub_url) if credhub_url.present? && cred_interpolation_enabled?
 

spec/request/apps_spec.rb

@@ -1601,6 +1601,20 @@
       end
 
       it_behaves_like 'permissions for single object endpoint', ALL_PERMISSIONS
+
+      context 'when file-based service bindings are enabled' do
+        let(:app_model_response_object) do
+          r = super()
+          r[:system_env_json] = { SERVICE_BINDING_ROOT: '/etc/cf-service-bindings' }
+          r
+        end
+
+        before do
+          app_model.update(file_based_service_bindings_enabled: true)
+        end
+
+        it_behaves_like 'permissions for single object endpoint', ALL_PERMISSIONS
+      end
     end
 
     context 'when VCAP_SERVICES contains potentially sensitive information' do

spec/unit/lib/cloud_controller/diego/environment_spec.rb

@@ -23,7 +23,7 @@ module VCAP::CloudController::Diego
       encoded_vcap_application_json = vcap_app.to_json
 
       vcap_services_key = :VCAP_SERVICES
-      system_env = SystemEnvPresenter.new(process.service_bindings).system_env
+      system_env = SystemEnvPresenter.new(process).system_env
       expect(system_env).to have_key(vcap_services_key)
 
       encoded_vcap_services_json = system_env[vcap_services_key].to_json