Ensure isolated plugins create pidfiles

Without this, when an isolated plugin creates a
process, we do not track it with a pidfile.
That in turn can lead to dangling processes
which do not get cleaned up with the
fix-unclean-shutdown command.

Author: cburgdorf

trinity/_utils/os.py

@@ -1,4 +1,6 @@
+import re
 import resource
+import unicodedata
 
 
 def get_open_fd_limit() -> int:
@@ -7,3 +9,17 @@ def get_open_fd_limit() -> int:
     """
     soft_limit, hard_limit = resource.getrlimit(resource.RLIMIT_NOFILE)
     return soft_limit
+
+
+def friendly_filename_or_url(value: str) -> str:
+    """
+    Normalize any string to be file name and URL friendly.
+    Convert to lowercase, remove non-alpha characters,
+    and convert spaces to hyphens.
+    """
+    # Taken from:
+    # https://stackoverflow.com/questions/295135/turn-a-string-into-a-valid-filename/295466#295466
+    value = str(unicodedata.normalize('NFKD', value).encode('ascii', 'ignore'))
+    value = str(re.sub('[^\w\s-]', '', value).strip().lower())
+    value = str(re.sub('[-\s]+', '-', value))
+    return value

trinity/extensibility/plugin.py

@@ -50,6 +50,9 @@
 from trinity._utils.logging import (
     setup_queue_logging,
 )
+from trinity._utils.os import (
+    friendly_filename_or_url,
+)
 
 
 class PluginStatus(Enum):
@@ -135,6 +138,13 @@ def name(self) -> str:
         """
         pass
 
+    @property
+    def normalized_name(self) -> str:
+        """
+        The normalized (computer readable) name of the plugin
+        """
+        return friendly_filename_or_url(self.name)
+
     @property
     def logger(self) -> logging.Logger:
         """
@@ -296,7 +306,8 @@ def _prepare_start(self) -> None:
         self.event_bus.broadcast(
             PluginStartedEvent(type(self))
         )
-        self.do_start()
+        with self.context.trinity_config.process_id_file(self.normalized_name):
+            self.do_start()
 
     def stop(self) -> None:
         """