playbook: Check Zope availability before exposure

As frontend can be already available, but still not serving correct content
check that it returns ZMI (Zope Management Interface) before providing it
as working for the user.

playbook/roles/standalone-shared/files/erp5-show

@@ -131,7 +131,24 @@ def status():
         frontend = 'https://' + ip
     frontend_ip, _ = get_connection_information(frn_sr)
 
-    if zope_ip is None or frontend is None or frontend_ip is None:
+    connected = False
+    if frontend is not None:
+      # as frontend is already up, check if all is ready to serve requests
+      # before providing the access url to the user
+      ctx = ssl.create_default_context()
+      ctx.check_hostname = False
+      ctx.verify_mode = ssl.CERT_NONE
+
+      try:
+        r1 = urllib2.urlopen(frontend, context=ctx)
+        if 'Zope Management Interface' in r1.read():
+          connected = True
+        else:
+          print 'URL %s ready, but does not reply with Zope' % frontend
+      except urllib2.URLError, e:
+        print "Zope not available yet: %s" % e
+
+    if zope_ip is None or frontend is None or frontend_ip is None or not connected:
       print "Build successful, please wait for instantiation"
       sys.exit(2)