V3 Fix 🐞: Scaling a process with extreme memory results in an UnknownError

[#171659728]

Authored-by: Merric De Launey <mdelauney@pivotal.io>

Author: MerricdeLauney

app/messages/process_scale_message.rb

@@ -7,7 +7,7 @@ class ProcessScaleMessage < BaseMessage
     validates_with NoAdditionalKeysValidator
 
     validates :instances, numericality: { only_integer: true, greater_than_or_equal_to: 0 }, allow_nil: true
-    validates :memory_in_mb, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
+    validates :memory_in_mb, numericality: { only_integer: true, greater_than: 0, less_than_or_equal_to: MAX_DB_INT }, allow_nil: true
     validates :disk_in_mb, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
   end
 end

spec/request/processes_spec.rb

@@ -741,6 +741,32 @@
       })
     end
 
+    it 'returns a helpful error when the meemory is too large' do
+      process = VCAP::CloudController::ProcessModel.make(
+        :process,
+        app:        app_model,
+        type:       'web',
+        instances:  2,
+        memory:     1024,
+        disk_quota: 1024,
+        command:    'rackup',
+      )
+
+      scale_request = {
+        memory_in_mb: 100000000000,
+      }
+
+      post "/v3/processes/#{process.guid}/actions/scale", scale_request.to_json, developer_headers
+
+      # parsed_response = MultiJson.load(last_response.body)
+
+      expect(last_response.status).to eq(422)
+      expect(parsed_response['errors'][0]['detail']).to eq 'Memory in mb must be less than or equal to 2147483647'
+
+      process.reload
+      expect(process.memory).to eq(1024)
+    end
+
     it 'ensures that the memory allocation is greater than existing sidecar memory allocation' do
       process = VCAP::CloudController::ProcessModel.make(
         :process,

spec/unit/messages/process_scale_message_spec.rb

@@ -74,6 +74,18 @@ module VCAP::CloudController
       end
     end
 
+    context 'when memory_in_mb is > the max value allowed in the database' do
+      let(:params) { { memory_in_mb: 0 } }
+
+      it 'is not valid' do
+        message = ProcessScaleMessage.new(params)
+
+        expect(message).not_to be_valid
+        expect(message.errors.count).to eq(1)
+        expect(message.errors[:memory_in_mb]).to include('must be greater than 0')
+      end
+    end
+
     context 'when memory_in_mb is not an integer' do
       let(:params) { { memory_in_mb: 3.5 } }