Updates for Standard Edition

Instance name is modified because SQLEXPRESS is used as an instance name for SQL Server. In Standard or Enterprise installs, SQL Server will default to MSSQLSERVER. Any instance name declared by the user will have MSSQL$ appeneded to the front as the service name.
Agent name needs to be declared because if you use the SQL Agent, you need to restart both services as the Agent is dependent on the SQL Service
If you have declared an agent account it will restart both the agent service and the sql service. If not only restart the sql service
SQL Server requires a reboot to complete your install

recipes/server.rb

@@ -20,10 +20,20 @@
 
 Chef::Application.fatal!("node['sql_server']['server_sa_password'] must be set for this cookbook to run") if node['sql_server']['server_sa_password'].nil?
 
-service_name = if node['sql_server']['instance_name'] == 'SQLEXPRESS'
+# SQLEXPRESS is used as an instance name in Standard or Enterprise installs 
+# SQL Server it will default to MSSQLSERVER. Any instance name used will 
+# have MSSQ$ appeneded to the front
+service_name = if node['sql_server']['instance_name'] == 'MSSQLSERVER'
+                 node['sql_server']['instance_name']
+               else
                  "MSSQL$#{node['sql_server']['instance_name']}"
+               end
+# Agent name needs to be declared because if you use the SQL Agent, you need
+# to restart both services as the Agent is dependent on the SQL Service
+agent_service_name = if node['sql_server']['instance_name'] == 'MSSQLSERVER'
+                 'SQLSERVERAGENT'
                else
-                 node['sql_server']['instance_name']
+                 "SQLAgent$#{node['sql_server']['instance_name']}"
                end
 
 # Compute registry version based on sql server version
@@ -90,6 +100,8 @@
   installer_type :custom
   options "/q /ConfigurationFile=#{config_file_path} #{passwords_options}"
   action :install
+  notifies :request_reboot, 'reboot[sql server install]'
+  returns [0, 42, 127, 3010]
 end
 
 # set the static tcp port
@@ -100,8 +112,25 @@
   notifies :restart, "service[#{service_name}]", :immediately
 end
 
-service service_name do
-  action [:start, :enable]
+# If you have declared an agent account it will restart both the
+# agent service and the sql service. If not only the sql service
+if node['sql_server']['agent_account']
+  service agent_service_name do
+    action [:start, :enable]
+  end
+  service service_name do
+    action [:start, :enable]
+  end
+else
+  service service_name do
+    action [:start, :enable]
+  end
+end
+
+# SQL Server requires a reboot to complete your install
+reboot 'sql server install' do
+  action :nothing
+  reason 'Needs to reboot after installing SQL Server'
 end
 
 include_recipe 'sql_server::client'