Fix the command show_alarms.

With zabbix 3.0 the API has changed and it is not possible
to get the hostname value via trigger.get(). This is because
the expandData parameter got deprecated in 2.4 and removed in 3.0.

bin/zabbix-cli

@@ -200,6 +200,7 @@ if __name__ == '__main__':
             os.system('clear')
 
             cli = zabbixcli(logs,conf,username,password,auth_token)
+
             cli.cmdloop()
 
         #

zabbix_cli/cli.py

@@ -103,6 +103,13 @@ def __init__(self,logs,conf,username='',password='',auth_token=''):
 
             self.api_auth_token = self.zapi.login(self.api_username,self.api_password,self.api_auth_token)
 
+            #
+            # Populate the dictionary used as a cache with hostid and
+            # hostname data
+            #
+
+            self.hostid_cache = self.populate_hostid_cache()
+
             if self.conf.logging == 'ON':
                 self.logs.logger.debug('Connected to Zabbix JSON-API')
 
@@ -439,7 +446,7 @@ def do_show_host(self,args):
             if self.conf.logging == 'ON':
                 self.logs.logger.error('Problems getting host information - %s',e)
 
-            self.generate_feddback('Error','Problems getting host information')
+            self.generate_feedback('Error','Problems getting host information')
             return False   
 
         #
@@ -1135,7 +1142,7 @@ def do_show_alarms(self,args):
         #
 
         try:
-            query=ast.literal_eval("{'withLastEventUnacknowledged':3,'search':{'description':'" + description + "'},'skipDependent':1,'monitored':1,'active':1,'output':'extend','expandDescription':1,'expandData':'hostname','sortfield':'lastchange','sortorder':'DESC','searchWildcardsEnabled':'True','filter':{'value':'1'" + filters + "}," + groupids + "}")
+            query=ast.literal_eval("{'selectHosts':'host','withLastEventUnacknowledged':3,'search':{'description':'" + description + "'},'skipDependent':1,'monitored':1,'active':1,'output':'extend','expandDescription':1,'sortfield':'lastchange','sortorder':'DESC','searchWildcardsEnabled':'True','filter':{'value':'1'" + filters + "}," + groupids + "}")
 
 
         except Exception as e:
@@ -1176,7 +1183,7 @@ def do_show_alarms(self,args):
             if self.output_format == 'json':
 
                 result_columns [result_columns_key] = {'triggerid':trigger['triggerid'],
-                                                       'hostname':trigger['hostname'],
+                                                       'hostname':self.get_host_name(trigger['host'][0]['hostid']),
                                                        'description':trigger['description'],
                                                        'severity':self.get_trigger_severity(int(trigger['priority'])),
                                                        'lastchange':str(lastchange),
@@ -1215,7 +1222,7 @@ def do_show_alarms(self,args):
                     ansi_end = ''
 
                 result_columns [result_columns_key] = {'1':trigger['triggerid'],
-                                                       '2':trigger['hostname'],
+                                                       '2':self.get_host_name(trigger['hosts'][0]['hostid']),
                                                        '3':'\n  '.join(textwrap.wrap("* " + trigger['description'],62)),
                                                        '4':ansi_code + self.get_trigger_severity(int(trigger['priority'])).upper() + ansi_end,
                                                        '5':str(lastchange),
@@ -6211,13 +6218,25 @@ def get_host_name(self, hostid):
 
         try:
 
-            data = self.zapi.host.get(output='extend',
-                                      hostids=hostid)
+            # 
+            # Return the value if it exists from the dictionary
+            # hostid_cache.
+            #
 
-            if data != []:
-                host_name = data[0]['host']
+            if hostid in self.hostid_cache:
+                host_name = self.hostid_cache[hostid]
+
             else:
-                raise Exception('Could not find hostname for ID:' + hostid)
+
+                data = self.zapi.host.get(output=['name'],
+                                          hostids=hostid)
+
+                if data != []:
+                    host_name = data[0]['name']
+                    self.hostid_cache[hostid] = host_name
+
+                else:
+                    raise Exception('Could not find hostname for ID:' + hostid)
 
         except Exception as e:
             raise e
@@ -6461,7 +6480,48 @@ def get_random_proxyid(self,proxy):
 
         else:
             raise Exception('The proxy list is empty')
+
+
+    # #################################################
+    # Method populate_hostid_cache
+    # #################################################
+
+    def populate_hostid_cache(self):
+        '''
+        DESCRIPTION:
+        Populate hostid cache
+        '''
+
+        # This methos initializes a dictionary when we start
+        # zabbix-cli with all hostid:hostname from hosts that are
+        # monitored. We use this as a cache to get hostname
+        # information for a hostid.
+        #
+        # This cache is necessary e.g. by the show_alarms to avoid an
+        # API call per active trigger to get the hostname of the host
+        # with the associated trigger because this is a very expensive
+        # operation on big systems with many active triggers.
+        #
+        # This has to be done this way now because with zabbix 3.0 the
+        # API has changed and it is not possible to get the hostname
+        # value via trigger.get(). expandData parameter got
+        # deprecated in 2.4 and removed in 3.0.
+        #
+
+        try:
+            temp_dict = {}
+
+            data = self.zapi.host.get(output=['hostid','name'],
+                                      monitored_hosts=True)
+
+            for host in data:
+                temp_dict[host['hostid']] = host['name'] 
+
+            return temp_dict
 
+        except Exception as e:
+            raise e
+
 
     # ############################################
     # Method preloop