Implement LogMonitorEH API

lib/tfw/components/log_monitoring_event_handler.py

@@ -4,12 +4,34 @@
 
 from tfw import EventHandlerBase
 from tfw.mixins import MonitorManagerMixin
+from tfw.config.logs import logging
 from .log_monitor import LogMonitor
 
+LOG = logging.getLogger(__name__)
+
 
 class LogMonitoringEventHandler(EventHandlerBase, MonitorManagerMixin):
-    def __init__(self, process_name, log_tail=0):
-        MonitorManagerMixin.__init__(self, LogMonitor, process_name, log_tail)
+    def __init__(self, key, process_name, log_tail=0):
+        super().__init__(key)
+        self.process_name = process_name
+        self.log_tail = log_tail
+        MonitorManagerMixin.__init__(self, LogMonitor, self.process_name, self.log_tail)
+
+        self.command_handlers = {
+            'process_name': self.handle_process_name,
+            'log_tail':     self.handle_log_tail
+        }
 
     def handle_event(self, message):
-        pass
+        try:
+            data = message['data']
+            self.command_handlers[data['command']](data)
+            self.reload_monitor()
+        except KeyError:
+            LOG.error('IGNORING MESSAGE: Invalid message received: %s', message)
+
+    def handle_process_name(self, data):
+        self.set_monitor_args(data['process_name'], self.log_tail)
+
+    def handle_log_tail(self, data):
+        self.set_monitor_args(self.process_name, data['log_tail'])