Add "default" field to v3 stacks

app/fetchers/stack_list_fetcher.rb

@@ -15,6 +15,13 @@ def filter(message, dataset)
           dataset = dataset.where(name: message.names)
         end
 
+        if message.requested?(:default)
+          condition = { name: Stack.default.name }.yield_self do |c|
+            ActiveModel::Type::Boolean.new.cast(message.default) ? c : Sequel.~(c)
+          end
+          dataset = dataset.where(condition)
+        end
+
         if message.requested?(:label_selector)
           dataset = LabelSelectorQueryGenerator.add_selector_queries(
             label_klass: StackLabelModel,

app/messages/purge_message.rb

@@ -7,7 +7,7 @@ class PurgeMessage < BaseMessage
     ]
 
     validates_with NoAdditionalParamsValidator
-    validates :purge, inclusion: { in: %w(true false), message: "only accepts values 'true' or 'false'" }, allow_nil: true
+    validates :purge, boolean_string: true, allow_nil: true
 
     def self.from_params(params)
       super(params, [])

app/messages/security_group_list_message.rb

@@ -15,8 +15,8 @@ class SecurityGroupListMessage < ListMessage
     validates :names, array: true, allow_nil: true
     validates :running_space_guids, array: true, allow_nil: true
     validates :staging_space_guids, array: true, allow_nil: true
-    validates :globally_enabled_running, inclusion: { in: %w(true false) }, allow_nil: true
-    validates :globally_enabled_staging, inclusion: { in: %w(true false) }, allow_nil: true
+    validates :globally_enabled_running, boolean_string: true, allow_nil: true
+    validates :globally_enabled_staging, boolean_string: true, allow_nil: true
 
     def self.from_params(params)
       super(params, %w(names running_space_guids staging_space_guids))

app/messages/service_offerings_list_message.rb

@@ -19,7 +19,7 @@ class ServiceOfferingsListMessage < MetadataListMessage
     register_allowed_keys(@single_keys + @array_keys)
 
     validates_with NoAdditionalParamsValidator
-    validates :available, inclusion: { in: %w(true false), message: "only accepts values 'true' or 'false'" }, allow_nil: true
+    validates :available, boolean_string: true, allow_nil: true
 
     validates :fields, allow_nil: true, fields: {
       allowed: {

app/messages/service_plans_list_message.rb

@@ -24,7 +24,7 @@ class ServicePlansListMessage < MetadataListMessage
 
     validates_with NoAdditionalParamsValidator
     validates_with IncludeParamValidator, valid_values: %w(space.organization service_offering)
-    validates :available, inclusion: { in: %w(true false), message: "only accepts values 'true' or 'false'" }, allow_nil: true
+    validates :available, boolean_string: true, allow_nil: true
 
     validates :fields, allow_nil: true, fields: {
       allowed: {

app/messages/stacks_list_message.rb

@@ -2,13 +2,12 @@
 
 module VCAP::CloudController
   class StacksListMessage < MetadataListMessage
-    register_allowed_keys [
-      :names,
-    ]
+    register_allowed_keys [:names, :default,]
 
     validates_with NoAdditionalParamsValidator
 
     validates :names, array: true, allow_nil: true
+    validates :default, boolean_string: true, allow_nil: true
 
     def self.from_params(params)
       super(params, %w(names))

app/messages/validators.rb

@@ -40,6 +40,18 @@ def boolean?(value)
     end
   end
 
+  class BooleanStringValidator < ActiveModel::EachValidator
+    def validate_each(record, attribute, value)
+      record.errors.add attribute, message: "must be 'true' or 'false'" unless boolean?(value)
+    end
+
+    private
+
+    def boolean?(value)
+      ['true', 'false'].include? value
+    end
+  end
+
   class HashValidator < ActiveModel::EachValidator
     def validate_each(record, attribute, value)
       record.errors.add attribute, message: 'must be an object' unless value.is_a?(Hash)

app/models/runtime/stack.rb

@@ -41,6 +41,12 @@ def before_destroy
       super
     end
 
+    def default?
+      self == Stack.default
+    rescue MissingDefaultStackError
+      false
+    end
+
     def self.configure(file_path)
       @config_file = if file_path
                        ConfigFile.new(file_path)

app/presenters/v3/stack_presenter.rb

@@ -12,6 +12,7 @@ def to_hash
         updated_at: stack.updated_at,
         name: stack.name,
         description: stack.description,
+        default: stack.default?,
         metadata: {
           labels: hashified_labels(stack.labels),
           annotations: hashified_annotations(stack.annotations),

docs/v3/source/includes/api_resources/_stacks.erb

@@ -5,6 +5,7 @@
    "updated_at": "2018-11-09T22:43:28Z",
    "name": "my-stack",
    "description": "Here is my stack!",
+   "default": true,
    "metadata": {
      "labels": <%= metadata.fetch(:labels, {}).to_json(space: ' ', object_nl: ' ')%>,
      "annotations": <%= metadata.fetch(:annotations, {}).to_json(space: ' ', object_nl: ' ')%>
@@ -40,6 +41,7 @@
       "updated_at": "2018-11-09T22:43:28Z",
       "name": "my-stack-1",
       "description": "This is my first stack!",
+      "default": true,
       "metadata": {
         "labels": {},
         "annotations": {}
@@ -56,6 +58,7 @@
       "updated_at": "2018-11-09T22:43:29Z",
       "name": "my-stack-2",
       "description": "This is my second stack!",
+      "default": false,
       "metadata": {
         "labels": {},
         "annotations": {}

docs/v3/source/includes/concepts/_lifecycles.md.erb

@@ -30,6 +30,10 @@ This is the default lifecycle for Cloud Foundry for VMs. When staging an app wit
 compiled using a buildpack, resulting in a droplet.  When running an app with this lifecycle, a container running a rootfs
 will be created and the droplet will be expanded inside that container to be executed.
 
+If buildpacks are not specified, then Cloud Foundry will automatically detect a
+compatible buildpack, based on the files in an app's package. If a stack is not
+specified, then the app will default to the operator-configured default stack.
+
 **Note**: This lifecycle is not supported on Cloud Foundry for Kubernetes.
 
 #### Buildpack lifecycle object

docs/v3/source/includes/resources/stacks/_list.md.erb

@@ -31,6 +31,7 @@ Retrieve all stacks.
 Name | Type | Description
 ---- | ---- | ------------
 **names** | _list of strings_ | Comma-delimited list of app names to filter by
+**default** | _boolean_ | If true, only return the default stack
 **page** | _integer_ | Page to display; valid values are integers >= 1
 **per_page** | _integer_ | Number of results per page; <br>valid values are 1 through 5000
 **order_by** | _string_ | Value to sort by. Defaults to ascending; prepend with `-` to sort descending<br>Valid values are `created_at`, `updated_at`, and `name`

docs/v3/source/includes/resources/stacks/_object.md.erb

@@ -14,6 +14,7 @@ Name | Type | Description
 **updated_at** | _[timestamp](#timestamps)_ | The time with zone when the object was last updated
 **name** | _string_ | The name of the stack
 **description** | _string_ | The description of the stack
+**default** | _boolean_ | Whether the stack is configured to be the default stack for new applications.
 **metadata.labels** | [_label object_](#labels) | Labels applied to the stack
 **metadata.annotations**  | [_annotation object_](#annotations) | Annotations applied to the stack
 **links** | [_links object_](#links) | Links to related resources

spec/request/stacks_spec.rb

@@ -2,9 +2,13 @@
 require 'request_spec_shared_examples'
 
 RSpec.describe 'Stacks Request' do
+  let(:stack_config_file) { File.join(Paths::FIXTURES, 'config/stacks.yml') }
+  let(:default_stack_name) { 'default-stack-name' }
   let(:org) { VCAP::CloudController::Organization.make(created_at: 3.days.ago) }
   let(:space) { VCAP::CloudController::Space.make(organization: org) }
 
+  before { VCAP::CloudController::Stack.configure(stack_config_file) }
+
   describe 'GET /v3/stacks' do
     before { VCAP::CloudController::Stack.dataset.destroy }
     let(:user) { make_user }
@@ -13,57 +17,44 @@
 
     context 'lists all stacks' do
       it_behaves_like 'permissions for list endpoint', ALL_PERMISSIONS do
-        let(:stacks_response_object) do
-          {
-            'pagination' => {
-              'total_results' => 3,
-              'total_pages' => 2,
-              'first' => {
-                'href' => "#{link_prefix}/v3/stacks?page=1&per_page=2"
-              },
-              'last' => {
-                'href' => "#{link_prefix}/v3/stacks?page=2&per_page=2"
-              },
-              'next' => {
-                'href' => "#{link_prefix}/v3/stacks?page=2&per_page=2"
-              },
-              'previous' => nil
-            },
-            'resources' => [
-              {
-                'name' => stack1.name,
-                'description' => stack1.description,
-                'guid' => stack1.guid,
-                'metadata' => { 'labels' => {}, 'annotations' => {} },
-                'created_at' => iso8601,
-                'updated_at' => iso8601,
-                'links' => {
-                  'self' => {
-                    'href' => "#{link_prefix}/v3/stacks/#{stack1.guid}"
-                  }
+        let(:stacks_response_objects) do
+          [
+            {
+              'name' => stack1.name,
+              'description' => stack1.description,
+              'guid' => stack1.guid,
+              'default' => false,
+              'metadata' => { 'labels' => {}, 'annotations' => {} },
+              'created_at' => iso8601,
+              'updated_at' => iso8601,
+              'links' => {
+                'self' => {
+                  'href' => "#{link_prefix}/v3/stacks/#{stack1.guid}"
                 }
-              },
-              {
-                'name' => stack2.name,
-                'description' => stack2.description,
-                'guid' => stack2.guid,
-                'metadata' => { 'labels' => {}, 'annotations' => {} },
-                'created_at' => iso8601,
-                'updated_at' => iso8601,
-                'links' => {
-                  'self' => {
-                    'href' => "#{link_prefix}/v3/stacks/#{stack2.guid}"
-                  }
+              }
+            },
+            {
+              'name' => stack2.name,
+              'description' => stack2.description,
+              'guid' => stack2.guid,
+              'default' => true,
+              'metadata' => { 'labels' => {}, 'annotations' => {} },
+              'created_at' => iso8601,
+              'updated_at' => iso8601,
+              'links' => {
+                'self' => {
+                  'href' => "#{link_prefix}/v3/stacks/#{stack2.guid}"
                 }
               }
-            ]
-          }
+            }
+          ]
         end
+
         let(:expected_codes_and_responses) do
-          Hash.new(code: 200, response_object: stacks_response_object)
+          Hash.new(code: 200, response_objects: stacks_response_objects)
         end
         let!(:stack1) { VCAP::CloudController::Stack.make }
-        let!(:stack2) { VCAP::CloudController::Stack.make }
+        let!(:stack2) { VCAP::CloudController::Stack.make(name: default_stack_name) }
       end
     end
 
@@ -82,6 +73,7 @@
         let(:params) do
           {
             names: ['foo', 'bar'],
+            default: true,
             page:   '2',
             per_page:   '10',
             order_by:   'updated_at',
@@ -91,11 +83,12 @@
             updated_ats: { gt: Time.now.utc.iso8601 },
           }
         end
+        let!(:stack) { VCAP::CloudController::Stack.make(name: default_stack_name) }
       end
 
       context 'When stacks exist' do
         let!(:stack1) { VCAP::CloudController::Stack.make }
-        let!(:stack2) { VCAP::CloudController::Stack.make }
+        let!(:stack2) { VCAP::CloudController::Stack.make(name: default_stack_name) }
         let!(:stack3) { VCAP::CloudController::Stack.make }
 
         it 'returns a paginated list of stacks' do
@@ -122,6 +115,7 @@
                   'name' => stack1.name,
                   'description' => stack1.description,
                   'guid' => stack1.guid,
+                  'default' => false,
                   'metadata' => { 'labels' => {}, 'annotations' => {} },
                   'created_at' => iso8601,
                   'updated_at' => iso8601,
@@ -135,6 +129,7 @@
                   'name' => stack2.name,
                   'description' => stack2.description,
                   'guid' => stack2.guid,
+                  'default' => true,
                   'metadata' => { 'labels' => {}, 'annotations' => {} },
                   'created_at' => iso8601,
                   'updated_at' => iso8601,
@@ -171,6 +166,7 @@
                   'name' => stack1.name,
                   'description' => stack1.description,
                   'guid' => stack1.guid,
+                  'default' => false,
                   'metadata' => { 'labels' => {}, 'annotations' => {} },
                   'created_at' => iso8601,
                   'updated_at' => iso8601,
@@ -184,6 +180,7 @@
                   'name' => stack3.name,
                   'description' => stack3.description,
                   'guid' => stack3.guid,
+                  'default' => false,
                   'metadata' => { 'labels' => {}, 'annotations' => {} },
                   'created_at' => iso8601,
                   'updated_at' => iso8601,
@@ -198,6 +195,43 @@
           )
         end
 
+        it 'returns a list of stacks filtered by whether they are default' do
+          get '/v3/stacks?default=true', nil, user_header
+
+          expect(parsed_response).to be_a_response_like(
+            {
+              'pagination' => {
+                'total_results' => 1,
+                'total_pages' => 1,
+                'first' => {
+                  'href' => "#{link_prefix}/v3/stacks?default=true&page=1&per_page=50"
+                },
+                'last' => {
+                  'href' => "#{link_prefix}/v3/stacks?default=true&page=1&per_page=50"
+                },
+                'next' => nil,
+                'previous' => nil
+              },
+              'resources' => [
+                {
+                  'name' => stack2.name,
+                  'description' => stack2.description,
+                  'guid' => stack2.guid,
+                  'default' => true,
+                  'metadata' => { 'labels' => {}, 'annotations' => {} },
+                  'created_at' => iso8601,
+                  'updated_at' => iso8601,
+                  'links' => {
+                    'self' => {
+                      'href' => "#{link_prefix}/v3/stacks/#{stack2.guid}"
+                    }
+                  }
+                }
+              ]
+            }
+          )
+        end
+
         context 'when there are labels' do
           let!(:stack1_label) { VCAP::CloudController::StackLabelModel.make(
             key_name: 'release',
@@ -234,6 +268,7 @@
                     'name' => stack1.name,
                     'description' => stack1.description,
                     'guid' => stack1.guid,
+                    'default' => false,
                     'metadata' => {
                       'labels' => {
                         'release' => 'stable'
@@ -267,6 +302,7 @@
         'name' => stack.name,
         'description' => stack.description,
         'guid' => stack.guid,
+        'default' => false,
         'metadata' => { 'labels' => {}, 'annotations' => {} },
         'created_at' => iso8601,
         'updated_at' => iso8601,
@@ -581,6 +617,7 @@
         {
           'name' => 'the-name',
           'description' => 'the-description',
+          'default' => false,
           'metadata' => {
             'labels' => {
               'potato' => 'yam'
@@ -642,6 +679,7 @@
         {
           'name' => stack.name,
           'description' => stack.description,
+          'default' => false,
           'metadata' => {
             'labels' => {
               'potato' => 'yam'