agents/plugins/nginx_status

   1 #!/usr/bin/python
   2 # -*- encoding: utf-8; py-indent-offset: 4 -*-
   3 # +------------------------------------------------------------------+
   4 # |             ____ _               _        __  __ _  __           |
   5 # |            / ___| |__   ___  ___| | __   |  \/  | |/ /           |
   6 # |           | |   | '_ \ / _ \/ __| |/ /   | |\/| | ' /            |
   7 # |           | |___| | | |  __/ (__|   <    | |  | | . \            |
   8 # |            \____|_| |_|\___|\___|_|\_\___|_|  |_|_|\_\           |
   9 # |                                                                  |
  10 # | Copyright Mathias Kettner 2014             mk@mathias-kettner.de |
  11 # +------------------------------------------------------------------+
  12 #
  13 # This file is part of Check_MK.
  14 # The official homepage is at http://mathias-kettner.de/check_mk.
  15 #
  16 # check_mk is free software;  you can redistribute it and/or modify it
  17 # under the  terms of the  GNU General Public License  as published by
  18 # the Free Software Foundation in version 2.  check_mk is  distributed
  19 # in the hope that it will be useful, but WITHOUT ANY WARRANTY;  with-
  20 # out even the implied warranty of  MERCHANTABILITY  or  FITNESS FOR A
  21 # PARTICULAR PURPOSE. See the  GNU General Public License for more de-
  22 # tails. You should have  received  a copy of the  GNU  General Public
  23 # License along with GNU Make; see the file  COPYING.  If  not,  write
  24 # to the Free Software Foundation, Inc., 51 Franklin St,  Fifth Floor,
  25 # Boston, MA 02110-1301 USA.
  26
  27 # Check_MK-Agent-Plugin - Nginx Server Status
  28 #
  29 # Fetches the stub nginx_status page from detected or configured nginx
  30 # processes to gather status information about this process.
  31 #
  32 # Take a look at the check man page for details on how to configure this
  33 # plugin and check.
  34 #
  35 # By default this plugin tries to detect all locally running processes
  36 # and to monitor them. If this is not good for your environment you might
  37 # create an nginx_status.cfg file in MK_CONFDIR and populate the servers
  38 # list to prevent executing the detection mechanism.
  39
  40 import os
  41 import re
  42 import sys
  43 import urllib2
  44
  45 # tell urllib2 not to honour "http(s)_proxy" env variables
  46 urllib2.getproxies = lambda: {}
  47
  48 config_dir = os.getenv("MK_CONFDIR", "/etc/check_mk")
  49 config_file = config_dir + "/nginx_status.cfg"
  50
  51 # None or list of (proto, ipaddress, port) tuples.
  52 # proto is 'http' or 'https'
  53 servers = None
  54 ssl_ports = [
  55     443,
  56 ]
  57
  58 if os.path.exists(config_file):
  59     execfile(config_file)
  60
  61
  62 def try_detect_servers():
  63     pids = []
  64     results = []
  65     for netstat_line in os.popen('netstat -tlnp 2>/dev/null').readlines():
  66         parts = netstat_line.split()
  67         # Skip lines with wrong format
  68         if len(parts) < 7 or '/' not in parts[6]:
  69             continue
  70
  71         pid, proc = parts[6].split('/', 1)
  72         to_replace = re.compile('^.*/')
  73         proc = to_replace.sub('', proc)
  74
  75         procs = ['nginx', 'nginx:', 'nginx.conf']
  76         # the pid/proc field length is limited to 19 chars. Thus in case of
  77         # long PIDs, the process names are stripped of by that length.
  78         # Workaround this problem here
  79         procs = [p[:19 - len(pid) - 1] for p in procs]
  80
  81         # Skip unwanted processes
  82         if proc not in procs:
  83             continue
  84
  85         # Add only the first found port of a single server process
  86         if pid in pids:
  87             continue
  88         pids.append(pid)
  89
  90         server_proto = 'http'
  91         server_address, server_port = parts[3].rsplit(':', 1)
  92         server_port = int(server_port)
  93
  94         # Use localhost when listening globally
  95         if server_address == '0.0.0.0':
  96             server_address = '127.0.0.1'
  97         elif server_address == '::':
  98             server_address = '::1'
  99
 100         # Switch protocol if port is SSL port. In case you use SSL on another
 101         # port you would have to change/extend the ssl_port list
 102         if server_port in ssl_ports:
 103             server_proto = 'https'
 104
 105         results.append((server_proto, server_address, server_port))
 106
 107     return results
 108
 109
 110 if servers is None:
 111     servers = try_detect_servers()
 112
 113 if not servers:
 114     sys.exit(0)
 115
 116 sys.stdout.write('<<<nginx_status>>>\n')
 117 for server in servers:
 118     if isinstance(server, tuple):
 119         proto, address, port = server
 120         page = 'nginx_status'
 121     else:
 122         proto = server['protocol']
 123         address = server['address']
 124         port = server['port']
 125         page = server.get('page', 'nginx_status')
 126
 127     try:
 128         url = '%s://%s:%s/%s' % (proto, address, port, page)
 129         # Try to fetch the status page for each server
 130         try:
 131             request = urllib2.Request(url, headers={"Accept": "text/plain"})
 132             fd = urllib2.urlopen(request)
 133         except urllib2.URLError, e:
 134             if 'SSL23_GET_SERVER_HELLO:unknown protocol' in str(e):
 135                 # HACK: workaround misconfigurations where port 443 is used for
 136                 # serving non ssl secured http
 137                 url = 'http://%s:%s/%s' % (address, port, page)
 138                 fd = urllib2.urlopen(url)
 139             else:
 140                 raise
 141
 142         for line in fd.read().split('\n'):
 143             if not line.strip():
 144                 continue
 145             if line.lstrip()[0] == '<':
 146                 # seems to be html output. Skip this server.
 147                 break
 148             sys.stdout.write("%s %s %s\n" % (address, port, line))
 149     except urllib2.HTTPError, e:
 150         sys.stderr.write('HTTP-Error (%s:%d): %s %s\n' % (address, port, e.code, e))
 151
 152     except Exception, e:
 153         sys.stderr.write('Exception (%s:%d): %s\n' % (address, port, e))