amarisoft_mme: use/expose count paramter from MS config for MME

the UEs count param, if specified, is mapped into the config
values of the EPC so it can be used for template rendering.

Since we only have one count parameter, its added to the first
subscriber. 1 is the default value and its used when no count
param is specified.

this allows to run the Amarisoft UE simulator with the Amarisoft EPC
without having to create subscriber entries for each simulated UE.

Change-Id: I29885791f716c204d0b6f18ba134885bae853b6f

src/osmo_gsm_tester/obj/epc_amarisoft.py

@@ -150,6 +150,10 @@ class AmarisoftEPC(epc.EPC):
         config.overlay(values, dict(epc=dict(log_filename=logfile,
                                              ifup_filename=ifupfile)))
 
+        # Retrieve and overlay UE count parameter to first subscriber
+        sub_count = self.testenv.suite().config().get('modem', None)
+        sub_count = sub_count['count'] if sub_count is not None and 'count' in sub_count else 1
+        self.subscriber_list[0]['count'] = sub_count
         config.overlay(values, dict(epc=dict(hss=dict(subscribers=self.subscriber_list))))
 
         self.dbg('SRSEPC CONFIG:\n' + pprint.pformat(values))

src/osmo_gsm_tester/templates/amarisoft_ltemme.cfg.tmpl

@@ -161,6 +161,7 @@
          with test SIM cards). They are distinguished with their
          IMEI. default = false. */
       multi_sim: false,
+      count: ${sub.count},
     },
 %endfor
     /* Add new entries for each IMSI/K */