Munin contributed plugins

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# vim: set fileencoding=utf-8

#

# Munin plugin to monitor nginx cache statuses.

#

# Copyright Igor Borodikhin

#

# License : GPLv3

#

# This plugin generates two graphs - with number of requests and with percents.

# Create these symlinks:

#    ln -s /usr/share/munin/plugins/nginx-cache-multi_ /etc/munin/plugins/nginx-cache-multi_number

#    ln -s /usr/share/munin/plugins/nginx-cache-multi_ /etc/munin/plugins/nginx-cache-multi_percent

#

# You can override the log file location.

#

#   [nginx-cache-multi]

#       env.logfile /var/log/nginx/cache-access.log

#

# Nginx must be configured to include "cs=$upstream_cache_status" in the

# log file. Example format:

#

# log_format cache '$remote_addr - $host [$time_local] "$request" $status '

#                  '$body_bytes_sent "$http_referer" '

#                  'rt=$request_time ut="$upstream_response_time" '

#                  'cs=$upstream_cache_status';

#%# capabilities=autoconf

#%# family=contrib

import os, sys, re

# How we've been called

prog_name = sys.argv[0]

prog_name = prog_name[prog_name.rfind("/")+1:]

# What is graph type?

graph_type = prog_name[prog_name.rfind("_")+1:]

# Where to store plugin state

if "MUNIN_PLUGSTATE" in os.environ:

    state_dir = os.environ["MUNIN_PLUGSTATE"]

else:

    state_dir = None

# Log path

if "logfile" in os.environ:

    log_file = os.environ["logfile"]

else:

    log_file = "/var/log/nginx/access.log"

cache_status_list = { "MISS" : 0, "EXPIRED" : 0, "UPDATING" : 0, "STALE" : 0, "HIT" : 0, "NONE" : 0, "TOTAL" : 0 }

if len(sys.argv) == 2 and sys.argv[1] == "autoconf":

    print "yes"

elif len(sys.argv) == 2 and sys.argv[1] == "config":

    graph_args = ""

    if graph_type == "number":

        vlabel = "requests"

    else:

        vlabel = "%"

        graph_args = "graph_args -l 0"

    # Parent graph declaration

    print "multigraph nginx_cache_multi_%s" % graph_type

    print "graph_title Nginx cache status (%s)" % graph_type

    print "graph_category webserver"

    print "graph_vlabel %s" % vlabel

    if graph_args:

         print(graph_args)

    for key in cache_status_list.keys():

        if key != "TOTAL":

            print "%s.label %s" % (key.lower(), key.capitalize())

            print "%s.draw AREASTACK" % key.lower()

            print "%s.min 0" % key.lower()

    print ""

    for key in cache_status_list.keys():

        # Other graphs declaration

        if key != "TOTAL":

            print "multigraph nginx_cache_multi_%s.%s" % (graph_type, key.lower())

            print "graph_title Nginx cache status (%s) - %s" % (graph_type, key.capitalize())

            print "graph_category webserver"

            print "graph_vlabel %s" % vlabel

            print "%s.label %s" % (key.lower(), key.capitalize())

            print "%s.draw LINE1" % key.lower()

            print "%s.min 0" % key.lower()

            print ""

else:

    last_byte_file = "%s/%s_state" % (state_dir, prog_name)

    last_byte_handle = None

    # Load last position in log file

    try:

        last_byte_handle = open(last_byte_file, "r")

        last_byte = int(last_byte_handle.read())

    except Exception:

        last_byte = 0

    if last_byte_handle != None:

        last_byte_handle.close()

    # Open log file for reading

    try:

        log_handle = open(log_file, "r")

    except Exception:

        print "Log file %s not readable" % log_file

        sys.exit(1)

    # Find out log size and set proper position depending on log size

    try:

        log_size = int(os.path.getsize(log_file))

    except ValueError:

        log_size = 0

    if log_size < last_byte:

        last_byte = 0

    # Set position on file

    log_handle.seek(last_byte)

    reg_exp = re.compile(r"cs=([^\s]+)")

    for line in log_handle:

        match = reg_exp.search(line)

        cache_status = match.group(1)

        if cache_status == "-":

            cache_status = "NONE"

        cache_status_list[cache_status] += 1

        cache_status_list["TOTAL"] += 1

    try:

        last_byte_handle = open(last_byte_file, "w")

        last_byte_handle.write(str(log_handle.tell()))

        last_byte_handle.close()

    except Exception:

        sys.exit(1)

    log_handle.close()

    # Handle graph type (_num for absolute numbers and anything else for percents)

    if graph_type != "number":

        for key in cache_status_list.keys():

            if key != "TOTAL":

                cache_status_list[key] = cache_status_list[key] * 100 / cache_status_list["TOTAL"]

        cache_status_list["TOTAL"] = 100

    # Parent graph declaration

    print "multigraph nginx_cache_multi_%s" % graph_type

    #print "total.value %s" % cache_status_list["TOTAL"]

    for key in cache_status_list.keys():

        if key != "TOTAL":

            print "%s.value %s" % (key.lower(), cache_status_list[key])

    print ""

    for key in cache_status_list.keys():

        # Other graphs declaration

        if key != "TOTAL":

            print "multigraph nginx_cache_multi_%s.%s" % (graph_type, key.lower())

            print "total.value %s" % cache_status_list["TOTAL"]

            print "%s.value %s" % (key.lower(), cache_status_list[key])

            print ""