scalability: add promise to check scalability user data

stack/erp5/buildout.cfg

@@ -325,7 +325,7 @@ md5sum = 19f6f1309bbefa651300a1802cab3fa0
 [template-scalability]
 < = download-base
 filename = instance-scalability.cfg.in
-md5sum = 399d803d3b8405d88905d6bbe84778ef
+md5sum = b9bcc5b3693eb9f999e749000d5e7dd1
 
 [template-zeo]
 < = download-base

stack/erp5/instance-scalability.cfg.in

@@ -10,6 +10,7 @@ parts =
   erp5-bootstrap
   erp5-promise
   promise-erp5-site
+  promise-scalability-user-data
   scalability-launcher-instance
   publish
 
@@ -130,6 +131,15 @@ url = ${erp5-cluster:connection-family-scalability}${:site-id}
 dash_path = {{ dash_location }}/bin/dash
 curl_path = {{ curl_location }}/bin/curl
 
+[promise-scalability-user-data]
+recipe = slapos.cookbook:check_url_available
+path = ${basedirectory:promises}/scalabilityData
+site-id = "/{{ site_id }}"
+page = "/person_module/scalability_user_0/getTitle"
+url = ${erp5-cluster:connection-family-scalability}${:site-id}${:page}
+dash_path = {{ dash_location }}/bin/dash
+curl_path = {{ curl_location }}/bin/curl
+
 [publish]
 recipe = slapos.cookbook:publish.serialised
 test = test