Implement /v3/spaces/#{space.guid}/usage_summary

Author: jochenehret

app/controllers/v3/spaces_controller.rb

@@ -211,6 +211,14 @@ def list_members
     raise CloudController::Errors::ApiError.new_from_details('UaaUnavailable')
   end
 
+  def show_usage_summary
+    space = fetch_space(hashed_params[:guid])
+    space_not_found! unless space
+    space_not_found! unless permission_queryer.can_read_from_space?(space.id, space.organization_id)
+
+    render status: :ok, json: Presenters::V3::SpaceUsageSummaryPresenter.new(org)
+  end
+
   private
 
   def fetch_organization(guid)

app/models/runtime/space.rb

@@ -269,6 +269,14 @@ def find_visible_service_instance_by_name(name)
       (shared | source).first
     end
 
+    def number_service_instances
+      service_instances_dataset.count
+    end
+
+    def number_service_keys
+      ServiceKey.where(service_instance_id: service_instances_dataset.select(:id)).count
+    end
+
     def self.user_visibility_filter(user)
       {
         spaces__id: user.space_developer_space_ids.
@@ -328,6 +336,14 @@ def members
       User.dataset.where(id: Role.where(space_id: id).distinct.select(:user_id))
     end
 
+    def memory_used
+      started_app_memory + running_task_memory
+    end
+
+    def running_and_pending_tasks_count
+      tasks_dataset.where(state: [TaskModel::PENDING_STATE, TaskModel::RUNNING_STATE]).count
+    end
+
     private
 
     def has_manager?(user)
@@ -339,7 +355,6 @@ def has_auditor?(user)
     end
 
     def memory_remaining
-      memory_used = started_app_memory + running_task_memory
       space_quota_definition.memory_limit - memory_used
     end
 
@@ -363,10 +378,6 @@ def started_app_log_rate_limit
       processes_dataset.where(state: ProcessModel::STARTED).sum(Sequel.*(:log_rate_limit, :instances)) || 0
     end
 
-    def running_and_pending_tasks_count
-      tasks_dataset.where(state: [TaskModel::PENDING_STATE, TaskModel::RUNNING_STATE]).count
-    end
-
     def validate_isolation_segment_set(isolation_segment_model)
       isolation_segment_guids = organization.isolation_segment_models.map(&:guid)
       return if isolation_segment_guids.include?(isolation_segment_model.guid)

app/presenters/v3/space_usage_summary_presenter.rb

@@ -0,0 +1,42 @@
+require 'presenters/v3/base_presenter'
+
+module VCAP::CloudController::Presenters::V3
+  class SpaceUsageSummaryPresenter < BasePresenter
+    def to_hash
+      {
+        usage_summary: {
+          started_instances: started_instances,
+          memory_in_mb: space.memory_used,
+          routes: space.routes_dataset.count,
+          service_instances: space.number_service_instances,
+          reserved_ports: VCAP::CloudController::SpaceReservedRoutePorts.new(space).count,
+          domains: space.organization.owned_private_domains_dataset.count,
+          per_app_tasks: space.running_and_pending_tasks_count,
+          service_keys: space.number_service_keys
+        },
+        links: build_links
+      }
+    end
+
+    private
+
+    def space
+      @resource
+    end
+
+    def started_instances
+      space.processes_dataset.where(state: VCAP::CloudController::ProcessModel::STARTED).sum(:instances) || 0
+    end
+
+    def build_links
+      {
+        self: {
+          href: url_builder.build_url(path: "/v3/spaces/#{space.guid}/usage_summary")
+        },
+        space: {
+          href: url_builder.build_url(path: "/v3/spaces/#{space.guid}")
+        }
+      }
+    end
+  end
+end

spec/unit/presenters/v3/space_usage_summary_presenter_spec.rb

@@ -0,0 +1,72 @@
+require 'spec_helper'
+require 'presenters/v3/space_usage_summary_presenter'
+
+module VCAP::CloudController::Presenters::V3
+  RSpec.describe SpaceUsageSummaryPresenter do
+    let(:org) { VCAP::CloudController::Organization.make }
+    let(:space) { VCAP::CloudController::Space.make(organization: org) }
+
+    context 'empty space' do
+      describe '#to_hash' do
+        let(:result) { SpaceUsageSummaryPresenter.new(space).to_hash }
+
+        it 'presents the space usage summary as json' do
+          expect(result[:usage_summary][:started_instances]).to eq(0)
+          expect(result[:usage_summary][:memory_in_mb]).to eq(0)
+          expect(result[:usage_summary][:routes]).to eq(0)
+          expect(result[:usage_summary][:service_instances]).to eq(0)
+          expect(result[:usage_summary][:reserved_ports]).to eq(0)
+          expect(result[:usage_summary][:domains]).to eq(0)
+          expect(result[:usage_summary][:per_app_tasks]).to eq(0)
+          expect(result[:usage_summary][:service_keys]).to eq(0)
+
+          expect(result[:links][:self][:href]).to match(%r{/v3/spaces/#{space.guid}/usage_summary$})
+          expect(result[:links][:space][:href]).to match(%r{/v3/spaces/#{space.guid}$})
+        end
+      end
+    end
+
+    context 'space with instances, routes and services' do
+      let(:app_model) { VCAP::CloudController::AppModel.make(name: 'App Model', space: space) }
+      let(:process) { VCAP::CloudController::ProcessModel.make(:process, state: VCAP::CloudController::ProcessModel::STARTED, memory: 512, app: app_model) }
+      let(:task) { VCAP::CloudController::TaskModel.make(app: app_model, state: VCAP::CloudController::TaskModel::RUNNING_STATE, memory_in_mb: 512) }
+      let(:shared_domain) { VCAP::CloudController::SharedDomain.make(router_group_guid: '123') }
+      let(:private_domain) { VCAP::CloudController::PrivateDomain.make(owning_organization: org) }
+      let(:route) { VCAP::CloudController::Route.make(host: '', domain: shared_domain, space: space, port: 4444) }
+      let(:broker) { VCAP::CloudController::ServiceBroker.make }
+      let(:service) { VCAP::CloudController::Service.make(service_broker: broker) }
+      let(:service_plan) { VCAP::CloudController::ServicePlan.make(service: service, public: true) }
+      let(:service_instance) { VCAP::CloudController::ManagedServiceInstance.make(space:, service_plan:) }
+      let(:service_key) { VCAP::CloudController::ServiceKey.make(service_instance:) }
+
+      describe '#to_hash' do
+        let(:result) { SpaceUsageSummaryPresenter.new(space).to_hash }
+
+        it 'presents the space usage summary as json' do
+          process # TODO: Ensure the process is created before the test runs
+          task
+
+          router_group = double('router_group', type: 'tcp', reservable_ports: [4444])
+          routing_api_client = double('routing_api_client', router_group: router_group, enabled?: true)
+          allow(CloudController::DependencyLocator).to receive(:instance).and_return(double(:api_client, routing_api_client:))
+          private_domain
+          route
+          service_instance
+          service_key
+
+          expect(result[:usage_summary][:started_instances]).to eq(1)
+          expect(result[:usage_summary][:memory_in_mb]).to eq(1024)
+          expect(result[:usage_summary][:routes]).to eq(1)
+          expect(result[:usage_summary][:service_instances]).to eq(1)
+          expect(result[:usage_summary][:reserved_ports]).to eq(1)
+          expect(result[:usage_summary][:domains]).to eq(1)
+          expect(result[:usage_summary][:per_app_tasks]).to eq(1)
+          expect(result[:usage_summary][:service_keys]).to eq(1)
+
+          expect(result[:links][:self][:href]).to match(%r{/v3/spaces/#{space.guid}/usage_summary$})
+          expect(result[:links][:space][:href]).to match(%r{/v3/spaces/#{space.guid}$})
+        end
+      end
+    end
+  end
+end