Backport the launcher as of commit 8321485315 to 1.3

This adds support for stale PID file checking (#182), as well as the --rehash/--stop/--restart options

launcher.py

@@ -0,0 +1,157 @@
+#!/usr/bin/env python3
+"""
+PyLink IRC Services launcher.
+"""
+
+import os
+import sys
+import signal
+import time
+from pylinkirc import world, conf, __version__, real_version
+
+try:
+    import psutil
+except ImportError:
+    psutil = None
+
+def main():
+    import argparse
+
+    parser = argparse.ArgumentParser(description='Starts an instance of PyLink IRC Services.')
+    parser.add_argument('config', help='specifies the path to the config file (defaults to pylink.yml)', nargs='?', default='pylink.yml')
+    parser.add_argument("-v", "--version", help="displays the program version and exits", action='store_true')
+    parser.add_argument("-c", "--check-pid", help="no-op; kept for compatiblity with PyLink 1.x", action='store_true')
+    parser.add_argument("-n", "--no-pid", help="skips generating and checking PID files", action='store_true')
+    parser.add_argument("-r", "--restart", help="restarts the PyLink instance with the given config file", action='store_true')
+    parser.add_argument("-s", "--stop", help="stops the PyLink instance with the given config file", action='store_true')
+    parser.add_argument("-R", "--rehash", help="rehashes the PyLink instance with the given config file", action='store_true')
+    args = parser.parse_args()
+
+    if args.version:  # Display version and exit
+        print('PyLink %s (in VCS: %s)' % (__version__, real_version))
+        sys.exit()
+
+    # XXX: repetitive
+    elif args.no_pid and (args.restart or args.stop or args.rehash):
+        print('ERROR: --no-pid cannot be combined with --restart or --stop')
+        sys.exit(1)
+    elif args.rehash and os.name != 'posix':
+        print('ERROR: Rehashing via the command line is not supported outside Unix.')
+        sys.exit(1)
+
+    # FIXME: we can't pass logging on to conf until we set up the config...
+    conf.loadConf(args.config)
+
+    from pylinkirc.log import log
+    from pylinkirc import classes, utils, coremods
+
+    # Write and check for an existing PID file unless specifically told not to.
+    if not args.no_pid:
+        pidfile = '%s.pid' % conf.confname
+        has_pid = False
+        pid = None
+        if os.path.exists(pidfile):
+
+            has_pid = True
+            if psutil is not None and os.name == 'posix':
+                # FIXME: Haven't tested this on other platforms, so not turning it on by default.
+                with open(pidfile) as f:
+                    try:
+                        pid = int(f.read())
+                        proc = psutil.Process(pid)
+                    except psutil.NoSuchProcess:  # Process doesn't exist!
+                        has_pid = False
+                        log.info("Ignoring stale PID %s from PID file %r: no such process exists.", pid, pidfile)
+                    else:
+                        # This PID got reused for something that isn't us?
+                        if not any('pylink' in arg.lower() for arg in proc.cmdline()):
+                            log.info("Ignoring stale PID %s from PID file %r: process command line %r is not us", pid, pidfile, proc.cmdline())
+                            has_pid = False
+
+        if has_pid:
+            if args.rehash:
+                os.kill(pid, signal.SIGUSR1)
+                log.info('OK, rehashed PyLink instance %s (config %r)', pid, args.config)
+                sys.exit()
+            elif args.stop or args.restart:  # Handle --stop and --restart options
+                os.kill(pid, signal.SIGTERM)
+
+                log.info("Waiting for PyLink instance %s (config %r) to stop...", pid, args.config)
+                while os.path.exists(pidfile):
+                    # XXX: this is ugly, but os.waitpid() only works on non-child processes on Windows
+                    time.sleep(0.2)
+                log.info("Successfully killed PID %s for config %r.", pid, args.config)
+
+                if args.stop:
+                    sys.exit()
+            else:
+                log.error("PID file %r exists; aborting!", pidfile)
+
+                if psutil is None:
+                    log.error("If PyLink didn't shut down cleanly last time it ran, or you're upgrading "
+                              "from PyLink < 1.1-dev, delete %r and start the server again.", pidfile)
+                    if os.name == 'posix':
+                        log.error("Alternatively, you can install psutil for Python 3 (pip3 install psutil), "
+                                  "which will allow this launcher to detect stale PID files and ignore them.")
+                sys.exit(1)
+        elif args.stop or args.restart or args.rehash:  # XXX: also repetitive
+            # --stop and --restart should take care of stale PIDs.
+            if pid:
+                world._should_remove_pid = True
+                log.error('Cannot stop/rehash PyLink: no process with PID %s exists.', pid)
+            else:
+                log.error('Cannot stop/rehash PyLink: PID file %r does not exist.', pidfile)
+            sys.exit(1)
+
+        with open(pidfile, 'w') as f:
+            f.write(str(os.getpid()))
+        world._should_remove_pid = True
+
+    log.info('PyLink %s starting...', __version__)
+
+    # Set terminal window title. See https://bbs.archlinux.org/viewtopic.php?id=85567
+    # and https://stackoverflow.com/questions/7387276/
+    if os.name == 'nt':
+        import ctypes
+        ctypes.windll.kernel32.SetConsoleTitleW("PyLink %s" % __version__)
+    elif os.name == 'posix':
+        sys.stdout.write("\x1b]2;PyLink %s\x07" % __version__)
+
+    # Load configured plugins
+    to_load = conf.conf['plugins']
+    utils.resetModuleDirs()
+
+    for plugin in to_load:
+        try:
+            world.plugins[plugin] = pl = utils.loadPlugin(plugin)
+        except Exception as e:
+            log.exception('Failed to load plugin %r: %s: %s', plugin, type(e).__name__, str(e))
+        else:
+            if hasattr(pl, 'main'):
+                log.debug('Calling main() function of plugin %r', pl)
+                pl.main()
+
+    # Initialize all the networks one by one
+    for network, sdata in conf.conf['servers'].items():
+        try:
+            protoname = sdata['protocol']
+        except (KeyError, TypeError):
+            log.error("(%s) Configuration error: No protocol module specified, aborting.", network)
+        else:
+            # Fetch the correct protocol module.
+            try:
+                proto = utils.getProtocolModule(protoname)
+
+                # Create and connect the network.
+                log.debug('Connecting to network %r', network)
+                world.networkobjects[network] = classes.Irc(network, proto, conf.conf)
+            except:
+                log.exception('(%s) Failed to connect to network %r, skipping it...',
+                              network, network)
+                continue
+
+    world.started.set()
+    log.info("Loaded plugins: %s", ', '.join(sorted(world.plugins.keys())))
+
+    from pylinkirc import coremods
+    coremods.permissions.resetPermissions()  # Future note: this is moved to run on import in 2.0

pylink

@@ -1,95 +1,13 @@
 #!/usr/bin/env python3
-"""
-PyLink IRC Services launcher.
-"""
-
-import os
 import sys
 try:
-    from pylinkirc import world
+    from pylinkirc import launcher
 except ImportError:
-    sys.stderr.write("ERROR: Failed to import PyLink main module (pylinkirc.world).\n\nIf you are "
+    print("ERROR: Failed to import PyLink launcher module (pylinkirc.launcher).\n\nIf you are "
           "running PyLink from source, please install PyLink first using 'python3 "
           "setup.py install' (global install) or 'python3 setup.py install --user'"
           " (local install)\n")
     sys.exit(1)
-from pylinkirc import conf, __version__, real_version
+else:
-
+    if __name__ == '__main__':
-if __name__ == '__main__':
+        launcher.main()
-    import argparse
-
-    parser = argparse.ArgumentParser(description='Starts an instance of PyLink IRC Services.')
-    parser.add_argument('config', help='specifies the path to the config file (defaults to pylink.yml)', nargs='?', default='pylink.yml')
-    parser.add_argument("-v", "--version", help="displays the program version and exits", action='store_true')
-    parser.add_argument("-c", "--check-pid", help="enables PID file checking", action='store_true')
-    parser.add_argument("-n", "--no-pid", help="skips generating PID files", action='store_true')
-    args = parser.parse_args()
-
-    if args.version:  # Display version and exit
-        print('PyLink %s (in VCS: %s)' % (__version__, real_version))
-        sys.exit()
-
-    # FIXME: we can't pass logging on to conf until we set up the config...
-    conf.loadConf(args.config)
-
-    from pylinkirc.log import log
-    from pylinkirc import classes, utils, coremods
-    log.info('PyLink %s starting...', __version__)
-
-    # Set terminal window title. See https://bbs.archlinux.org/viewtopic.php?id=85567
-    # and https://stackoverflow.com/questions/7387276/
-    if os.name == 'nt':
-        import ctypes
-        ctypes.windll.kernel32.SetConsoleTitleW("PyLink %s" % __version__)
-    elif os.name == 'posix':
-        sys.stdout.write("\x1b]2;PyLink %s\x07" % __version__)
-
-    # Check for a pid file. This stops instance overlap and user mistakes, which are especially an
-    # issue for clientbot...
-    if args.check_pid:
-        config = conf.confname
-        if os.path.exists("%s.pid" % config):
-            log.error("PID file exists; aborting! If PyLink didn't shut down cleanly last time it "
-                      "was run, or you're upgrading from PyLink < 1.1-dev, delete %s.pid and try "
-                      "again." % config)
-            sys.exit(1)
-
-    # Write a PID file unless specifically told not to.
-    if not args.no_pid:
-        with open('%s.pid' % conf.confname, 'w') as f:
-            f.write(str(os.getpid()))
-        world._should_remove_pid = True
-
-    # Import plugins first globally, because they can listen for events
-    # that happen before the connection phase.
-    to_load = conf.conf['plugins']
-    utils.resetModuleDirs()
-    # Here, we override the module lookup and import the plugins
-    # dynamically depending on which were configured.
-    for plugin in to_load:
-        try:
-            world.plugins[plugin] = pl = utils.loadPlugin(plugin)
-        except Exception as e:
-            log.exception('Failed to load plugin %r: %s: %s', plugin, type(e).__name__, str(e))
-        else:
-            if hasattr(pl, 'main'):
-                log.debug('Calling main() function of plugin %r', pl)
-                pl.main()
-
-    # Initialize all the networks one by one
-    for network, sdata in conf.conf['servers'].items():
-
-        try:
-            protoname = sdata['protocol']
-        except (KeyError, TypeError):
-            log.error("(%s) Configuration error: No protocol module specified, aborting.", network)
-        else:
-            # Fetch the correct protocol module
-            proto = utils.getProtocolModule(protoname)
-            world.networkobjects[network] = irc = classes.Irc(network, proto, conf.conf)
-
-    world.started.set()
-    log.info("Loaded plugins: %s", ', '.join(sorted(world.plugins.keys())))
-
-    from pylinkirc import coremods
-    coremods.permissions.resetPermissions()  # XXX we should probably move this to run on import

setup.py

@@ -80,6 +80,7 @@ setup(
 
     extras_require={
         'password-hashing': ['passlib'],
+        'cron-support': ['psutil'],
         'servprotect': ['expiringdict>=1.1.4'],
     },
 
@@ -98,5 +99,9 @@ setup(
     package_dir = {'pylinkirc': '.'},
 
     # Executable scripts
-    scripts=["pylink", "pylink-mkpasswd"],
+    scripts=["pylink-mkpasswd"],
+
+    entry_points = {
+        'console_scripts': ['pylink=pylinkirc.launcher:main'],
+    }
 )