Implement watchdog observer to watch the logs of a supervisor process

lib/tfw/components/__init__.py

@@ -7,3 +7,4 @@ from .terminal_event_handler import TerminalEventHandler
 from .ide_event_handler import IdeEventHandler
 from .history_monitor import HistoryMonitor, BashMonitor, GDBMonitor
 from .terminal_commands import TerminalCommands
+from .log_monitor import LogMonitor

lib/tfw/components/log_monitor.py

@@ -0,0 +1,43 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from os.path import dirname
+
+from watchdog.events import PatternMatchingEventHandler as PatternMatchingWatchdogEventHandler
+
+from tfw.networking.event_handlers import ServerUplinkConnector
+from tfw.decorators import RateLimiter
+from tfw.mixins import ObserverMixin, SupervisorLogMixin
+
+
+class LogMonitor(ObserverMixin):
+    def __init__(self, process_name):
+        ObserverMixin.__init__(self)
+        event_handler = SendLogWatchdogEventHandler(process_name)
+        self.observer.schedule(
+            event_handler,
+            event_handler.path
+        )
+
+
+class SendLogWatchdogEventHandler(PatternMatchingWatchdogEventHandler, SupervisorLogMixin):
+    def __init__(self, process_name):
+        self.process_name = process_name
+        self.procinfo = self.supervisor.getProcessInfo(self.process_name)
+        super().__init__([self.procinfo['stdout_logfile'], self.procinfo['stderr_logfile']])
+        self.uplink = ServerUplinkConnector()
+
+    @property
+    def path(self):
+        return dirname(self.procinfo['stdout_logfile'])
+
+    @RateLimiter(rate_per_second=5)
+    def on_modified(self, event):
+        self.uplink.send({
+            'key': 'console',
+            'data': {
+                'command': 'writelog',
+                'stdout': self.read_stdout(self.process_name),
+                'stderr': self.read_stderr(self.process_name)
+            }
+        })