Fix multiple file support in linux.file_watch.line + black + fstring

CHANGELOG.rst

@@ -7,7 +7,6 @@ in development
 Fixed
 ~~~~~
 
-
 * Fix deserialization bug in st2 API for url encoded payloads. #5536
 
   Contributed by @sravs-dev
@@ -176,6 +175,14 @@ Fixed
 
   Contributed by @minsis
 
+* Fixed trigger references emitted by ``linux.file_watch.line``. #5467
+
+  Prior to this patch multiple files could be watched but the rule reference of last registered file
+  would be used for all trigger emissions causing rule enforcement to fail.  References are now tracked
+  on a per file basis and used in trigger emissions.
+
+  Contributed by @nzlosh
+
 3.6.0 - October 29, 2021
 ------------------------
 

contrib/linux/sensors/file_watch_sensor.py

@@ -14,7 +14,6 @@
 # limitations under the License.
 
 import os
-
 import eventlet
 
 from logshipper.tail import Tail
@@ -27,44 +26,46 @@ def __init__(self, sensor_service, config=None):
         super(FileWatchSensor, self).__init__(
             sensor_service=sensor_service, config=config
         )
-        self._trigger = None
-        self._logger = self._sensor_service.get_logger(__name__)
-        self._tail = None
+        self.log = self._sensor_service.get_logger(__name__)
+        self.tail = None
+        self.file_ref = {}
 
     def setup(self):
-        self._tail = Tail(filenames=[])
-        self._tail.handler = self._handle_line
-        self._tail.should_run = True
+        self.tail = Tail(filenames=[])
+        self.tail.handler = self._handle_line
+        self.tail.should_run = True
 
     def run(self):
-        self._tail.run()
+        self.tail.run()
 
     def cleanup(self):
-        if self._tail:
-            self._tail.should_run = False
+        if self.tail:
+            self.tail.should_run = False
 
             try:
-                self._tail.notifier.stop()
+                self.tail.notifier.stop()
             except Exception:
-                self._logger.exception("Unable to stop the tail notifier")
+                self.log.exception("Unable to stop the tail notifier")
 
     def add_trigger(self, trigger):
         file_path = trigger["parameters"].get("file_path", None)
 
         if not file_path:
-            self._logger.error('Received trigger type without "file_path" field.')
+            self.log.error('Received trigger type without "file_path" field.')
             return
 
-        self._trigger = trigger.get("ref", None)
+        trigger = trigger.get("ref", None)
 
-        if not self._trigger:
-            raise Exception("Trigger %s did not contain a ref." % trigger)
+        if not trigger:
+            raise Exception(f"Trigger {trigger} did not contain a ref.")
 
         # Wait a bit to avoid initialization race in logshipper library
         eventlet.sleep(1.0)
 
-        self._tail.add_file(filename=file_path)
-        self._logger.info('Added file "%s"' % (file_path))
+        self.tail.add_file(filename=file_path)
+        self.file_ref[file_path] = trigger
+
+        self.log.info(f"Added file '{file_path}' ({trigger}) to watch list.")
 
     def update_trigger(self, trigger):
         pass
@@ -73,22 +74,28 @@ def remove_trigger(self, trigger):
         file_path = trigger["parameters"].get("file_path", None)
 
         if not file_path:
-            self._logger.error('Received trigger type without "file_path" field.')
+            self.log.error("Received trigger type without 'file_path' field.")
             return
 
-        self._tail.remove_file(filename=file_path)
-        self._trigger = None
+        self.tail.remove_file(filename=file_path)
+        self.file_ref.pop(file_path)
 
-        self._logger.info('Removed file "%s"' % (file_path))
+        self.log.info(f"Removed file '{file_path}' ({trigger}) from watch list.")
 
     def _handle_line(self, file_path, line):
-        trigger = self._trigger
+        if file_path not in self.file_ref:
+            self.log.error(
+                f"No reference found for {file_path}, unable to emit trigger!"
+            )
+            return
+
+        trigger = self.file_ref[file_path]
         payload = {
             "file_path": file_path,
             "file_name": os.path.basename(file_path),
             "line": line,
         }
-        self._logger.debug(
-            "Sending payload %s for trigger %s to sensor_service.", payload, trigger
+        self.log.debug(
+            f"Sending payload {payload} for trigger {trigger} to sensor_service."
         )
         self.sensor_service.dispatch(trigger=trigger, payload=payload)