add syslog support.

Add options to setup logging to syslog:

- `--log-syslog`: enable syslog. It default to `/var/run/syslog` on darwin,
  `/var/run/log` on freebsd, `/dev/log` on openbsd and udp://localhost:514 for
  other platforms.
- `--log-syslog-prefix: Pass the parameter to use as the program name
- `--log-syslog-to`: Setup the syslog address to send message. Address startinf
  by udp:// will send to udp, unix:// to a unix socket and tcp:// to tcp (useful
  for rsyslog)

fix #452 .

gunicorn/app/base.py

@@ -33,7 +33,6 @@ class Application(object):
             self.load_config()
         except Exception as e:
             sys.stderr.write("\nError: %s\n" % str(e))
-            traceback.print_exc()
             sys.stderr.flush()
             sys.exit(1)
 

gunicorn/config.py

@@ -22,6 +22,7 @@ from gunicorn import six
 from gunicorn import util
 
 KNOWN_SETTINGS = []
+PLATFORM = sys.platform
 
 
 def wrap_method(func):
@@ -70,9 +71,9 @@ class Config(object):
             "prog": self.prog
         }
         parser = argparse.ArgumentParser(**kwargs)
+        parser.add_argument("args", nargs="*", help=argparse.SUPPRESS)
 
         keys = list(self.settings)
-
         def sorter(k):
             return (self.settings[k].section, self.settings[k].order)
 
@@ -80,7 +81,8 @@ class Config(object):
         for k in keys:
             self.settings[k].add_option(parser)
 
-        parser.add_argument("args", nargs="*", help=argparse.SUPPRESS)
+
+
         return parser
 
     @property
@@ -175,6 +177,10 @@ class Setting(object):
     default = None
     short = None
     desc = None
+    nargs = None
+    const = None
+
+
 
     def __init__(self):
         if self.default is not None:
@@ -202,6 +208,12 @@ class Setting(object):
         if kwargs["action"] != "store":
             kwargs.pop("type")
 
+        if self.nargs is not None:
+            kwargs["nargs"] = self.nargs
+
+        if self.const is not None:
+            kwargs["const"] = self.const
+
         parser.add_argument(*args, **kwargs)
 
     def copy(self):
@@ -1217,3 +1229,48 @@ class CertFile(Setting):
     desc = """\
     SSL certificate file
     """
+
+
+class SyslogTo(Setting):
+    name = "syslog_addr"
+    section = "Logging"
+    cli = ["--log-syslog-to"]
+    meta = "SYSLOG_ADDR"
+    validator = validate_string
+
+    if PLATFORM == "darwin":
+        default = "unix:///var/run/syslog"
+    elif PLATFORM in ('freebsd', 'dragonfly', ):
+        default = "unix:///var/run/log"
+    elif PLATFORM == "openbsd":
+        default = "unix:///dev/log"
+    else:
+        default = "udp://localhost:514"
+
+    desc = """\
+    Address to send syslog messages
+    """
+
+class Syslog(Setting):
+    name = "syslog"
+    section = "Logging"
+    cli = ["--log-syslog"]
+    validator = validate_bool
+    action = 'store_true'
+    default = False
+    desc = """\
+    Log to syslog.
+    """
+
+
+class SyslogPrefix(Setting):
+    name = "syslog_prefix"
+    section = "Logging"
+    cli = ["--log-syslog-prefix"]
+    meta = "SYSLOG_PREFIX"
+    validator = validate_string
+    default = None
+    desc = """\
+    makes gunicorn use the parameter as program-name in the
+    syslog entry header.
+    """

gunicorn/glogging.py

@@ -8,6 +8,7 @@ import logging
 logging.Logger.manager.emittedNoHandlerWarning = 1
 from logging.config import fileConfig
 import os
+import socket
 import sys
 import traceback
 import threading
@@ -123,6 +124,41 @@ class SafeAtoms(dict):
             return '-'
 
 
+def parse_syslog_address(addr):
+
+    if addr.startswith("unix://"):
+        return (socket.SOCK_STREAM, addr.split("unix://")[1])
+
+    if addr.startswith("udp://"):
+        addr = addr.split("udp://")[1]
+        socktype = socket.SOCK_DGRAM
+    elif addr.startswith("tcp://"):
+        addr = addr.split("tcp://")[1]
+        socktype = socket.SOCK_STREAM
+    else:
+        raise RuntimeError("invalid syslog address")
+
+    if '[' in addr and ']' in addr:
+        host = addr.split(']')[0][1:].lower()
+    elif ':' in addr:
+        host = addr.split(':')[0].lower()
+    elif addr == "":
+        host = "localhost"
+    else:
+        host = addr.lower()
+
+    addr = addr.split(']')[-1]
+    if ":" in addr:
+        port = addr.split(':', 1)[1]
+        if not port.isdigit():
+            raise RuntimeError("%r is not a valid port number." % port)
+        port = int(port)
+    else:
+        port = 514
+
+    return (socktype, (host, port))
+
+
 class Logger(object):
 
     LOG_LEVELS = {
@@ -137,10 +173,12 @@ class Logger(object):
     datefmt = r"%Y-%m-%d %H:%M:%S"
 
     access_fmt = "%(message)s"
+    syslog_fmt = "[%(process)d] %(message)s"
 
     def __init__(self, cfg):
         self.error_log = logging.getLogger("gunicorn.error")
         self.access_log = logging.getLogger("gunicorn.access")
+
         self.error_handlers = []
         self.access_handlers = []
         self.cfg = cfg
@@ -165,6 +203,11 @@ class Logger(object):
             if cfg.accesslog is not None:
                 self._set_handler(self.access_log, cfg.accesslog,
                     fmt=logging.Formatter(self.access_fmt))
+
+
+            if cfg.syslog:
+                self._set_syslog_handler(self.error_log, cfg, self.syslog_fmt)
+
         else:
             if os.path.exists(cfg.logconfig):
                 fileConfig(cfg.logconfig, defaults=CONFIG_DEFAULTS,
@@ -296,3 +339,19 @@ class Logger(object):
         h.setFormatter(fmt)
         h._gunicorn = True
         log.addHandler(h)
+
+    def _set_syslog_handler(self, log, cfg, fmt):
+        # setup format
+        if not cfg.syslog_prefix:
+            prefix = cfg.proc_name.replace(":", ".")
+        prefix = "gunicorn.%s" % prefix
+        fmt = logging.Formatter(r"%s: %s" % (prefix, fmt))
+
+        # parse syslog address
+        socktype, addr = parse_syslog_address(cfg.syslog_addr)
+
+        # finally setup the syslog handler
+        h = logging.handlers.SysLogHandler(address=addr, socktype=socktype)
+        h.setFormatter(fmt)
+        h._gunicorn = True
+        log.addHandler(h)

gunicorn/util.py

@@ -224,6 +224,13 @@ def parse_address(netloc, default_port=8000):
     if netloc.startswith("unix:"):
         return netloc.split("unix:")[1]
 
+    if netloc.startswith("unix://"):
+        return netloc.split("unix://")[1]
+
+    if netloc.startswith("tcp://"):
+        netloc = netloc.split("tcp://")[1]
+
+
     # get host
     if '[' in netloc and ']' in netloc:
         host = netloc.split(']')[0][1:].lower()
@@ -245,7 +252,6 @@ def parse_address(netloc, default_port=8000):
         port = default_port
     return (host, port)
 
-
 def get_maxfd():
     maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
     if (maxfd == resource.RLIM_INFINITY):