from __future__ import print_function # (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org) # Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php # @@: This should be moved to paste.deploy # For discussion of daemonizing: # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/278731 # Code taken also from QP: # http://www.mems-exchange.org/software/qp/ # From lib/site.py import atexit import errno import logging import os import re import subprocess import sys import threading import time import traceback from paste.deploy import loadapp, loadserver from paste.script.command import Command, BadCommand MAXFD = 1024 jython = sys.platform.startswith('java') class DaemonizeException(Exception): pass class ServeCommand(Command): min_args = 0 usage = 'CONFIG_FILE [start|stop|restart|status] [var=value]' takes_config_file = 1 summary = "Serve the described application" description = """\ This command serves a web application that uses a paste.deploy configuration file for the server and application. If start/stop/restart is given, then --daemon is implied, and it will start (normal operation), stop (--stop-daemon), or do both. You can also include variable assignments like 'http_port=8080' and then use %(http_port)s in your config files. """ # used by subclasses that configure apps and servers differently requires_config_file = True parser = Command.standard_parser(quiet=True) parser.add_option('-n', '--app-name', dest='app_name', metavar='NAME', help="Load the named application (default main)") parser.add_option('-s', '--server', dest='server', metavar='SERVER_TYPE', help="Use the named server.") parser.add_option('--server-name', dest='server_name', metavar='SECTION_NAME', help="Use the named server as defined in the configuration file (default: main)") if hasattr(os, 'fork'): parser.add_option('--daemon', dest="daemon", action="store_true", help="Run in daemon (background) mode") parser.add_option('--pid-file', dest='pid_file', metavar='FILENAME', help="Save PID to file (default to paster.pid if running in daemon mode)") parser.add_option('--log-file', dest='log_file', metavar='LOG_FILE', help="Save output to the given log file (redirects stdout)") parser.add_option('--reload', dest='reload', action='store_true', help="Use auto-restart file monitor") parser.add_option('--reload-interval', dest='reload_interval', default=1, help="Seconds between checking files (low number can cause significant CPU usage)") parser.add_option('--monitor-restart', dest='monitor_restart', action='store_true', help="Auto-restart server if it dies") parser.add_option('--status', action='store_true', dest='show_status', help="Show the status of the (presumably daemonized) server") if hasattr(os, 'setuid'): # I don't think these are available on Windows parser.add_option('--user', dest='set_user', metavar="USERNAME", help="Set the user (usually only possible when run as root)") parser.add_option('--group', dest='set_group', metavar="GROUP", help="Set the group (usually only possible when run as root)") parser.add_option('--stop-daemon', dest='stop_daemon', action='store_true', help='Stop a daemonized server (given a PID file, or default paster.pid file)') if jython: parser.add_option('--disable-jython-reloader', action='store_true', dest='disable_jython_reloader', help="Disable the Jython reloader") _scheme_re = re.compile(r'^[a-z][a-z]+:', re.I) default_verbosity = 1 _reloader_environ_key = 'PYTHON_RELOADER_SHOULD_RUN' _monitor_environ_key = 'PASTE_MONITOR_SHOULD_RUN' possible_subcommands = ('start', 'stop', 'restart', 'status') def command(self): if self.options.stop_daemon: return self.stop_daemon() if not hasattr(self.options, 'set_user'): # Windows case: self.options.set_user = self.options.set_group = None # @@: Is this the right stage to set the user at? self.change_user_group( self.options.set_user, self.options.set_group) if self.requires_config_file: if not self.args: raise BadCommand('You must give a config file') app_spec = self.args[0] if (len(self.args) > 1 and self.args[1] in self.possible_subcommands): cmd = self.args[1] restvars = self.args[2:] else: cmd = None restvars = self.args[1:] else: app_spec = "" if (self.args and self.args[0] in self.possible_subcommands): cmd = self.args[0] restvars = self.args[1:] else: cmd = None restvars = self.args[:] if (getattr(self.options, 'daemon', False) and getattr(self.options, 'reload', False)): raise BadCommand('The --daemon and --reload options may not be used together') jython_monitor = False if self.options.reload: if jython and not self.options.disable_jython_reloader: # JythonMonitor raises the special SystemRestart # exception that'll cause the Jython interpreter to # reload in the existing Java process (avoiding # subprocess startup time) try: from paste.reloader import JythonMonitor except ImportError: pass else: jython_monitor = JythonMonitor(poll_interval=int( self.options.reload_interval)) if self.requires_config_file: jython_monitor.watch_file(self.args[0]) if not jython_monitor: if os.environ.get(self._reloader_environ_key): from paste import reloader if self.verbose > 1: print('Running reloading file monitor') reloader.install(int(self.options.reload_interval)) if self.requires_config_file: reloader.watch_file(self.args[0]) else: return self.restart_with_reloader() if cmd not in (None, 'start', 'stop', 'restart', 'status'): raise BadCommand( 'Error: must give start|stop|restart (not %s)' % cmd) if cmd == 'status' or self.options.show_status: return self.show_status() if cmd == 'restart' or cmd == 'stop': result = self.stop_daemon() if result: if cmd == 'restart': print("Could not stop daemon; aborting") else: print("Could not stop daemon") return result if cmd == 'stop': return result self.options.daemon = True if cmd == 'start': self.options.daemon = True app_name = self.options.app_name vars = self.parse_vars(restvars) if not self._scheme_re.search(app_spec): app_spec = 'config:' + app_spec server_name = self.options.server_name if self.options.server: server_spec = 'egg:PasteScript' assert server_name is None server_name = self.options.server else: server_spec = app_spec base = os.getcwd() if getattr(self.options, 'daemon', False): if not self.options.pid_file: self.options.pid_file = 'paster.pid' if not self.options.log_file: self.options.log_file = 'paster.log' # Ensure the log file is writeable if self.options.log_file: try: writeable_log_file = open(self.options.log_file, 'a') except IOError as ioe: msg = 'Error: Unable to write to log file: %s' % ioe raise BadCommand(msg) writeable_log_file.close() # Ensure the pid file is writeable if self.options.pid_file: try: writeable_pid_file = open(self.options.pid_file, 'a') except IOError as ioe: msg = 'Error: Unable to write to pid file: %s' % ioe raise BadCommand(msg) writeable_pid_file.close() if getattr(self.options, 'daemon', False): try: self.daemonize() except DaemonizeException as ex: if self.verbose > 0: print(str(ex)) return if (self.options.monitor_restart and not os.environ.get(self._monitor_environ_key)): return self.restart_with_monitor() if self.options.pid_file: self.record_pid(self.options.pid_file) if self.options.log_file: stdout_log = LazyWriter(self.options.log_file, 'a') sys.stdout = stdout_log sys.stderr = stdout_log logging.basicConfig(stream=stdout_log) log_fn = app_spec if log_fn.startswith('config:'): log_fn = app_spec[len('config:'):] elif log_fn.startswith('egg:'): log_fn = None if log_fn: log_fn = os.path.join(base, log_fn) self.logging_file_config(log_fn) try: server = self.loadserver(server_spec, name=server_name, relative_to=base, global_conf=vars) app = self.loadapp(app_spec, name=app_name, relative_to=base, global_conf=vars) except SyntaxError as e: if self.options.reload and os.environ.get(self._reloader_environ_key): traceback.print_exc() reloader.watch_file(e.filename) while True: time.sleep(60*60) else: raise if self.verbose > 0: if hasattr(os, 'getpid'): msg = 'Starting server in PID %i.' % os.getpid() else: msg = 'Starting server.' print(msg) def serve(): try: server(app) except (SystemExit, KeyboardInterrupt) as e: if self.verbose > 1: raise if str(e): msg = ' '+str(e) else: msg = '' print('Exiting%s (-v to see traceback)' % msg) if jython_monitor: # JythonMonitor has to be ran from the main thread threading.Thread(target=serve).start() print('Starting Jython file monitor') jython_monitor.periodic_reload() else: serve() def loadserver(self, server_spec, name, relative_to, **kw): return loadserver( server_spec, name=name, relative_to=relative_to, **kw) def loadapp(self, app_spec, name, relative_to, **kw): return loadapp( app_spec, name=name, relative_to=relative_to, **kw) def daemonize(self): pid = live_pidfile(self.options.pid_file) if pid: raise DaemonizeException( "Daemon is already running (PID: %s from PID file %s)" % (pid, self.options.pid_file)) if self.verbose > 0: print('Entering daemon mode') pid = os.fork() if pid: # The forked process also has a handle on resources, so we # *don't* want proper termination of the process, we just # want to exit quick (which os._exit() does) os._exit(0) # Make this the session leader os.setsid() # Fork again for good measure! pid = os.fork() if pid: os._exit(0) # @@: Should we set the umask and cwd now? import resource # Resource usage information. maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1] if (maxfd == resource.RLIM_INFINITY): maxfd = MAXFD # Iterate through and close all file descriptors. for fd in range(0, maxfd): try: os.close(fd) except OSError: # ERROR, fd wasn't open to begin with (ignored) pass if (hasattr(os, "devnull")): REDIRECT_TO = os.devnull else: REDIRECT_TO = "/dev/null" os.open(REDIRECT_TO, os.O_RDWR) # standard input (0) # Duplicate standard input to standard output and standard error. os.dup2(0, 1) # standard output (1) os.dup2(0, 2) # standard error (2) def record_pid(self, pid_file): pid = os.getpid() if self.verbose > 1: print('Writing PID %s to %s' % (pid, pid_file)) f = open(pid_file, 'w') f.write(str(pid)) f.close() atexit.register(_remove_pid_file, pid, pid_file, self.verbose) def stop_daemon(self): pid_file = self.options.pid_file or 'paster.pid' if not os.path.exists(pid_file): print('No PID file exists in %s' % pid_file) return 1 pid = read_pidfile(pid_file) if not pid: print("Not a valid PID file in %s" % pid_file) return 1 pid = live_pidfile(pid_file) if not pid: print("PID in %s is not valid (deleting)" % pid_file) try: os.unlink(pid_file) except (OSError, IOError) as e: print("Could not delete: %s" % e) return 2 return 1 for j in range(10): if not live_pidfile(pid_file): break import signal os.kill(pid, signal.SIGINT) time.sleep(1) for j in range(10): if not live_pidfile(pid_file): break import signal os.kill(pid, signal.SIGTERM) time.sleep(1) else: print("failed to kill web process %s" % pid) return 3 if os.path.exists(pid_file): os.unlink(pid_file) return 0 def show_status(self): pid_file = self.options.pid_file or 'paster.pid' if not os.path.exists(pid_file): print('No PID file %s' % pid_file) return 1 pid = read_pidfile(pid_file) if not pid: print('No PID in file %s' % pid_file) return 1 pid = live_pidfile(pid_file) if not pid: print('PID %s in %s is not running' % (pid, pid_file)) return 1 print('Server running in PID %s' % pid) return 0 def restart_with_reloader(self): self.restart_with_monitor(reloader=True) def restart_with_monitor(self, reloader=False): if self.verbose > 0: if reloader: print('Starting subprocess with file monitor') else: print('Starting subprocess with monitor parent') while 1: args = [self.quote_first_command_arg(sys.executable)] + sys.argv new_environ = os.environ.copy() if reloader: new_environ[self._reloader_environ_key] = 'true' else: new_environ[self._monitor_environ_key] = 'true' proc = None try: try: _turn_sigterm_into_systemexit() proc = subprocess.Popen(args, env=new_environ) exit_code = proc.wait() proc = None except KeyboardInterrupt: print('^C caught in monitor process') if self.verbose > 1: raise return 1 finally: if (proc is not None and hasattr(os, 'kill')): import signal try: os.kill(proc.pid, signal.SIGTERM) except (OSError, IOError): pass if reloader: # Reloader always exits with code 3; but if we are # a monitor, any exit code will restart if exit_code != 3: return exit_code if self.verbose > 0: print('-'*20, 'Restarting', '-'*20) def change_user_group(self, user, group): if not user and not group: return import pwd, grp uid = gid = None if group: try: gid = int(group) group = grp.getgrgid(gid).gr_name except ValueError: import grp try: entry = grp.getgrnam(group) except KeyError: raise BadCommand( "Bad group: %r; no such group exists" % group) gid = entry.gr_gid try: uid = int(user) user = pwd.getpwuid(uid).pw_name except ValueError: try: entry = pwd.getpwnam(user) except KeyError: raise BadCommand( "Bad username: %r; no such user exists" % user) if not gid: gid = entry.pw_gid uid = entry.pw_uid if self.verbose > 0: print('Changing user to %s:%s (%s:%s)' % ( user, group or '(unknown)', uid, gid)) if hasattr(os, 'initgroups'): os.initgroups(user, gid) else: os.setgroups([e.gr_gid for e in grp.getgrall() if user in e.gr_mem] + [gid]) if gid: os.setgid(gid) if uid: os.setuid(uid) class LazyWriter(object): """ File-like object that opens a file lazily when it is first written to. """ def __init__(self, filename, mode='w'): self.filename = filename self.fileobj = None self.lock = threading.Lock() self.mode = mode def open(self): if self.fileobj is None: self.lock.acquire() try: if self.fileobj is None: self.fileobj = open(self.filename, self.mode) finally: self.lock.release() return self.fileobj def write(self, text): fileobj = self.open() fileobj.write(text) fileobj.flush() def writelines(self, text): fileobj = self.open() fileobj.writelines(text) fileobj.flush() def flush(self): self.open().flush() def live_pidfile(pidfile): """(pidfile:str) -> int | None Returns an int found in the named file, if there is one, and if there is a running process with that process id. Return None if no such process exists. """ pid = read_pidfile(pidfile) if pid: try: os.kill(int(pid), 0) return pid except OSError as e: if e.errno == errno.EPERM: return pid return None def read_pidfile(filename): if os.path.exists(filename): try: f = open(filename) content = f.read() f.close() return int(content.strip()) except (ValueError, IOError): return None else: return None def _remove_pid_file(written_pid, filename, verbosity): current_pid = os.getpid() if written_pid != current_pid: # A forked process must be exiting, not the process that # wrote the PID file return if not os.path.exists(filename): return f = open(filename) content = f.read().strip() f.close() try: pid_in_file = int(content) except ValueError: pass else: if pid_in_file != current_pid: print("PID file %s contains %s, not expected PID %s" % ( filename, pid_in_file, current_pid)) return if verbosity > 0: print("Removing PID file %s" % filename) try: os.unlink(filename) return except OSError as e: # Record, but don't give traceback print("Cannot remove PID file: %s" % e) # well, at least lets not leave the invalid PID around... try: f = open(filename, 'w') f.write('') f.close() except OSError as e: print('Stale PID left in file: %s (%e)' % (filename, e)) else: print('Stale PID removed') def ensure_port_cleanup(bound_addresses, maxtries=30, sleeptime=2): """ This makes sure any open ports are closed. Does this by connecting to them until they give connection refused. Servers should call like:: import paste.script ensure_port_cleanup([80, 443]) """ atexit.register(_cleanup_ports, bound_addresses, maxtries=maxtries, sleeptime=sleeptime) def _cleanup_ports(bound_addresses, maxtries=30, sleeptime=2): # Wait for the server to bind to the port. import socket import errno for bound_address in bound_addresses: for attempt in range(maxtries): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) try: sock.connect(bound_address) except socket.error as e: if e.args[0] != errno.ECONNREFUSED: raise break else: time.sleep(sleeptime) else: raise SystemExit('Timeout waiting for port.') sock.close() def _turn_sigterm_into_systemexit(): """ Attempts to turn a SIGTERM exception into a SystemExit exception. """ try: import signal except ImportError: return def handle_term(signo, frame): raise SystemExit signal.signal(signal.SIGTERM, handle_term)