Use tcp on port 3000 for puma when nginx socket is empty (#3939)

Author: johha

lib/cloud_controller/runners/puma_runner.rb

@@ -10,7 +10,11 @@ def initialize(config, app, logger, periodic_updater, request_logs)
 
       puma_config = Puma::Configuration.new do |conf|
         if config.get(:nginx, :use_nginx)
-          conf.bind "unix://#{config.get(:nginx, :instance_socket)}"
+          if config.get(:nginx, :instance_socket).nil? || config.get(:nginx, :instance_socket).empty?
+            conf.bind 'tcp://0.0.0.0:3000'
+          else
+            conf.bind "unix://#{config.get(:nginx, :instance_socket)}"
+          end
         else
           conf.bind "tcp://0.0.0.0:#{config.get(:external_port)}"
         end

spec/unit/lib/cloud_controller/runners/puma_runner_spec.rb

@@ -49,6 +49,15 @@ module VCAP::CloudController
         expect(puma_launcher.config.final_options[:binds].first).to eq("unix://#{socket}")
       end
 
+      context 'when socket is not configured' do
+        let(:socket) { '' }
+
+        it 'binds to the nginx default port 3000' do
+          subject
+          expect(puma_launcher.config.final_options[:binds].first).to eq('tcp://0.0.0.0:3000')
+        end
+      end
+
       context 'when not using nginx' do
         let(:use_nginx) { false }