Add option to check for deprecated stacks in pre-start rake task

app/models/runtime/stack.rb

@@ -100,6 +100,10 @@ def stacks
         @hash['stacks']
       end
 
+      def deprecated_stacks
+        @hash['deprecated_stacks']
+      end
+
       def default
         @hash['default']
       end
@@ -112,7 +116,10 @@ def default
             'description' => String,
             optional('build_rootfs_image') => String,
             optional('run_rootfs_image') => String
-          }]
+          }],
+          optional('deprecated_stacks') => [
+            String
+          ]
         }
       end
     end

config/stacks.yml

@@ -3,3 +3,8 @@ default: "cflinuxfs4"
 stacks:
   - name: "cflinuxfs4"
     description: "test cflinuxfs4 entry"
+
+
+
+
+deprecated_stacks: [ 'cflinuxfs3' ]

lib/cloud_controller/check_stacks.rb

@@ -0,0 +1,30 @@
+module VCAP::CloudController
+  class CheckStacks
+    attr_reader :config
+
+    def initialize(config)
+      @config = config
+      @stack_config = VCAP::CloudController::Stack::ConfigFile.new(config.get(:stacks_file))
+    end
+
+    def validate_stacks
+      deprecated_stacks = @stack_config.deprecated_stacks
+      return if deprecated_stacks.blank?
+
+      deprecated_stacks.each { |stack| validate_stack(stack) }
+    end
+
+    private
+
+    def validate_stack(deprecated_stack)
+      configured_stacks = @stack_config.stacks
+      deprecated_stack_in_config = (configured_stacks.find { |stack| stack['name'] == deprecated_stack }).present?
+
+      return if deprecated_stack_in_config
+
+      deprecated_stack_in_db = VCAP::CloudController::Stack.first(name: deprecated_stack).present?
+
+      raise "rake task 'stack_check' failed, stack '#{deprecated_stack}' not supported" if deprecated_stack_in_db
+    end
+  end
+end

lib/tasks/stack_check.rake

@@ -0,0 +1,14 @@
+namespace :stacks do
+  desc 'Check Installed Stacks'
+  task stack_check: :environment do
+    logger = Steno.logger('cc.stack')
+    VCAP::CloudController::Encryptor.db_encryption_key = RakeConfig.config.get(:db_encryption_key)
+    VCAP::CloudController::DB.connect(RakeConfig.config.get(:db), logger)
+
+    require 'models/runtime/buildpack_lifecycle_data_model'
+    require 'models/runtime/stack'
+    require 'cloud_controller/check_stacks'
+
+    VCAP::CloudController::CheckStacks.new(RakeConfig.config).validate_stacks
+  end
+end

spec/fixtures/config/invalid_stacks.yml

@@ -1,2 +1,4 @@
 stacks:
-  - unknown_key: true
+  - unknown_key: true
+
+deprecated_stacks: {} 

spec/fixtures/config/stacks.yml

@@ -7,3 +7,6 @@ stacks:
     description: "default-stack-description"
   - name: "cider"
     description: "cider-description"
+
+deprecated_stacks:
+  - old_stack

spec/unit/lib/cloud_controller/check_stacks_spec.rb

@@ -0,0 +1,122 @@
+require 'spec_helper'
+require 'yaml'
+require 'cloud_controller/check_stacks'
+require 'tasks/rake_config'
+
+module VCAP::CloudController
+  RSpec.describe CheckStacks do
+    let(:stack_file_contents) do
+      {
+        'default' => 'cflinuxfs4',
+        'stacks' => [
+          cflinuxfs4
+        ],
+        'deprecated_stacks' => 'cflinuxfs3'
+      }
+    end
+
+    let(:cflinuxfs3) { { 'name' => 'cflinuxfs3', 'description' => 'fs3' } }
+    let(:cflinuxfs4) { { 'name' => 'cflinuxfs4', 'description' => 'fs4' } }
+
+    before do
+      # binding.pry
+      Stack.dataset.destroy
+      file = Tempfile.new
+      file.write(stack_file_contents.to_yaml)
+      file.close
+      Stack.configure(file)
+      Stack.populate
+      TestConfig.override(stacks_file: file.path)
+    end
+
+    let(:stack_checker) { CheckStacks.new(TestConfig.config_instance) }
+
+    describe 'there deprecated stacks is nil' do
+      let(:stack_file_contents) do
+        {
+          'default' => 'cflinuxfs4',
+          'stacks' => [
+            cflinuxfs3,
+            cflinuxfs4
+          ]
+        }
+      end
+
+      it 'does nothing' do
+        expect { stack_checker.validate_stacks }.not_to raise_error
+      end
+    end
+
+    describe 'there are no deprecated stacks' do
+      let(:stack_file_contents) do
+        {
+          'default' => 'cflinuxfs4',
+          'stacks' => [
+            cflinuxfs3,
+            cflinuxfs4
+          ],
+          'deprecated_stacks' => []
+        }
+      end
+
+      it 'does nothing' do
+        expect { stack_checker.validate_stacks }.not_to raise_error
+      end
+    end
+
+    describe 'the deprecated stack is in the config' do
+      let(:stack_file_contents) do
+        {
+          'default' => 'cflinuxfs4',
+          'stacks' => [
+            cflinuxfs3,
+            cflinuxfs4
+          ],
+          'deprecated_stacks' => ['cflinuxfs3']
+        }
+      end
+
+      describe 'the deprecated stack is in the db' do
+        it 'does not raise an error' do
+          expect { stack_checker.validate_stacks }.not_to raise_error
+        end
+      end
+
+      describe 'the deprecated stack is not in the db' do
+        before do
+          Stack.first(name: 'cflinuxfs3').destroy
+        end
+
+        it 'does not raise an error' do
+          expect { stack_checker.validate_stacks }.not_to raise_error
+        end
+      end
+    end
+
+    describe 'when the deprecated stack is not in the config' do
+      let(:stack_file_contents) do
+        {
+          'default' => 'cflinuxfs4',
+          'stacks' => [cflinuxfs4],
+          'deprecated_stacks' => ['cflinuxfs3']
+        }
+      end
+
+      describe 'the deprecated stack is in the db' do
+        before do
+          Stack.make(name: 'cflinuxfs3')
+        end
+
+        it 'logs an error and exits 1' do
+          expect { stack_checker.validate_stacks }.to raise_error "rake task 'stack_check' failed, stack 'cflinuxfs3' not supported"
+        end
+      end
+
+      describe 'the deprecated stack is not in the db' do
+        it 'does not raise an error' do
+          expect { stack_checker.validate_stacks }.not_to raise_error
+        end
+      end
+    end
+  end
+end

spec/unit/models/runtime/stack_spec.rb

@@ -45,7 +45,8 @@ module VCAP::CloudController
 
         {
           default: 'default => Missing key',
-          stacks: 'name => Missing key'
+          stacks: 'name => Missing key',
+          deprecated_stacks: 'deprecated_stacks => Expected instance of Array, given instance of Hash }'
         }.each do |key, expected_error|
           it "requires #{key} (validates via '#{expected_error}')" do
             expect do