Refactor the stop command (#71)

Now several subfunctions are factored out from the rather lengthy `execute` function, in particular for stopping a native binary and for stopping a container.

src/qlever/commands/stop.py

@@ -1,15 +1,40 @@
 from __future__ import annotations
-
 import re
-
 import psutil
-
 from qlever.command import QleverCommand
 from qlever.commands.status import StatusCommand
 from qlever.containerize import Containerize
 from qlever.log import log
 from qlever.util import show_process_info
 
+# try to kill the given process, return true iff it was killed successfully.
+# the process_info is used for logging.
+def stop_process(proc, pinfo):
+    try:
+        proc.kill()
+        log.info(f"Killed process {pinfo['pid']}")
+        return True
+    except Exception as e:
+        log.error(f"Could not kill process with PID "
+                  f"{pinfo['pid']} ({e}) ... try to kill it "
+                  f"manually")
+        log.info("")
+        show_process_info(proc, "", show_heading=True)
+        return False
+
+
+# try to stop and remove container. return True iff it was stopped
+# successfully. Gives log info accordingly.
+def stop_container(server_container):
+    for container_system in Containerize.supported_systems():
+        if Containerize.stop_and_remove_container(
+                container_system, server_container):
+            log.info(f"{container_system.capitalize()} container with "
+                     f"name \"{server_container}\" stopped "
+                     f" and removed")
+            return True
+    return False
+
 
 class StopCommand(QleverCommand):
     """
@@ -20,7 +45,7 @@ def __init__(self):
         pass
 
     def description(self) -> str:
-        return ("Stop QLever server for a given datasedataset or port")
+        return "Stop QLever server for a given datasedataset or port"
 
     def should_have_qleverfile(self) -> bool:
         return True
@@ -54,46 +79,31 @@ def execute(self, args) -> bool:
         # First check if there is container running and if yes, stop and remove
         # it (unless the user has specified `--no-containers`).
         if not args.no_containers:
-            for container_system in Containerize.supported_systems():
-                if Containerize.stop_and_remove_container(
-                        container_system, args.server_container):
-                    log.info(f"{container_system.capitalize()} container with "
-                             f"name \"{args.server_container}\" stopped "
-                             f" and removed")
-                    return True
+            if stop_container(args.server_container):
+                return True
 
         # Check if there is a process running on the server port using psutil.
-        #
         # NOTE: On MacOS, some of the proc's returned by psutil.process_iter()
         # no longer exist when we try to access them, so we just skip them.
         for proc in psutil.process_iter():
             try:
                 pinfo = proc.as_dict(
-                        attrs=['pid', 'username', 'create_time',
-                               'memory_info', 'cmdline'])
+                    attrs=['pid', 'username', 'create_time',
+                           'memory_info', 'cmdline'])
                 cmdline = " ".join(pinfo['cmdline'])
             except Exception as e:
                 log.debug(f"Error getting process info: {e}")
+                return False
             if re.search(cmdline_regex, cmdline):
                 log.info(f"Found process {pinfo['pid']} from user "
                          f"{pinfo['username']} with command line: {cmdline}")
                 log.info("")
-                try:
-                    proc.kill()
-                    log.info(f"Killed process {pinfo['pid']}")
-                except Exception as e:
-                    log.error(f"Could not kill process with PID "
-                              f"{pinfo['pid']} ({e}) ... try to kill it "
-                              f"manually")
-                    log.info("")
-                    show_process_info(proc, "", show_heading=True)
-                    return False
-                return True
+                return stop_process(proc, pinfo)
 
         # If no matching process found, show a message and the output of the
         # status command.
         message = "No matching process found" if args.no_containers else \
-                  "No matching process or container found"
+            "No matching process or container found"
         log.error(message)
         args.cmdline_regex = "^ServerMain.* -i [^ ]*"
         log.info("")