Sudo

NRPE 問題無法讀取輸出 Check_Access_Log

  • July 15, 2013

在執行 xinetd 的 NRPE 中,我可以在本地執行腳本,但 NRPE 在嘗試遠端執行時報告無法讀取輸出。有什麼建議麼?:

   [root@travel log]# /usr/local/nagios/libexec/check_nrpe -H xxx.xxx.xxx.xxx -t 30 -c check_access_log -a -l /var/log/httpd/vhosts/xxxxxx/access_log
NRPE: Unable to read output

如果我直接在客戶端上執行腳本:

   ./check_access_log.pl -l /var/log/httpd/vhosts/xxxxxxx/access_log
ACCESS_STATUS OK - FAILURE_RATE 0 | Total=0;; FAIL=0%;10;20 BytesServed=0kB;; 20X=0;; 30X=0;; 403=0;; 404=0;; 40X=0;; 500=0;; 503=0;; 50X=0;; no_status=0;; Other=0;;

如果我執行檢查 NRPE:

[root@travel log]# /usr/local/nagios/libexec/check_nrpe -H xxx.xxx.xxx.xxx -t 30 -
NRPE v2.14

現在我正在使用 Xinetd.d 執行我的 NRPE:

# default: on
# description: NRPE (Nagios Remote Plugin Executor)
service nrpe
{
       flags           = REUSE
       socket_type     = stream
       port            = 5666
       wait            = no
       user            = nagios
       group           = nagios
       server          = /usr/local/nagios/bin/nrpe
       server_args     = -c /usr/local/nagios/etc/nrpe.cfg --inetd
       log_on_failure  += USERID
       disable         = no
       only_from       = xxx.xxx.xxx.xxx
}

這是我的 nrpe.cfg 文件。

#############################################################################
# Sample NRPE Config File 
# Written by: Ethan Galstad (nagios@nagios.org)
# 
# Last Modified: 11-23-2007
#
# NOTES:
# This is a sample configuration file for the NRPE daemon.  It needs to be
# located on the remote host that is running the NRPE daemon, not the host
# from which the check_nrpe client is being executed.
#############################################################################


# LOG FACILITY
# The syslog facility that should be used for logging purposes.

log_facility=daemon



# PID FILE
# The name of the file in which the NRPE daemon should write it's process ID
# number.  The file is only written if the NRPE daemon is started by the root
# user and is running in standalone mode.

pid_file=/var/run/nrpe.pid



# PORT NUMBER
# Port number we should wait for connections on.
# NOTE: This must be a non-priviledged port (i.e. > 1024).
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

server_port=5666



# SERVER ADDRESS
# Address that nrpe should bind to in case there are more than one interface
# and you do not want nrpe to bind on all interfaces.
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

#server_address=127.0.0.1



# NRPE USER
# This determines the effective user that the NRPE daemon should run as.  
# You can either supply a username or a UID.
# 
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_user=nagios



# NRPE GROUP
# This determines the effective group that the NRPE daemon should run as.  
# You can either supply a group name or a GID.
# 
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_group=nagios



# ALLOWED HOST ADDRESSES
# This is an optional comma-delimited list of IP address or hostnames 
# that are allowed to talk to the NRPE daemon.
#
# Note: The daemon only does rudimentary checking of the client's IP
# address.  I would highly recommend adding entries in your /etc/hosts.allow
# file to allow only the specified host to connect to the port
# you are running this daemon on.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

allowed_hosts=127.0.0.1



# COMMAND ARGUMENT PROCESSING
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments to commands that are executed.  This option only works
# if the daemon was configured with the --enable-command-args configure script
# option.  
#
# *** ENABLING THIS OPTION IS A SECURITY RISK! *** 
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#
# Values: 0=do not allow arguments, 1=allow command arguments

dont_blame_nrpe=1



# COMMAND PREFIX
# This option allows you to prefix all commands with a user-defined string.
# A space is automatically added between the specified prefix string and the
# command line from the command definition.
#
# *** THIS EXAMPLE MAY POSE A POTENTIAL SECURITY RISK, SO USE WITH CAUTION! ***
# Usage scenario: 
# Execute restricted commmands using sudo.  For this to work, you need to add
# the nagios user to your /etc/sudoers.  An example entry for alllowing 
# execution of the plugins from might be:
#
# nagios          ALL=(ALL) NOPASSWD: /usr/lib/nagios/plugins/
#
# This lets the nagios user run all commands in that directory (and only them)
# without asking for a password.  If you do this, make sure you don't give
# random users write access to that directory or its contents!

command_prefix=/usr/bin/sudo 



# DEBUGGING OPTION
# This option determines whether or not debugging messages are logged to the
# syslog facility.
# Values: 0=debugging off, 1=debugging on

debug=0



# COMMAND TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# allow plugins to finish executing before killing them off.

command_timeout=60



# CONNECTION TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# wait for a connection to be established before exiting. This is sometimes
# seen where a network problem stops the SSL being established even though
# all network sessions are connected. This causes the nrpe daemons to
# accumulate, eating system resources. Do not set this too low.

connection_timeout=300



# WEEK RANDOM SEED OPTION
# This directive allows you to use SSL even if your system does not have
# a /dev/random or /dev/urandom (on purpose or because the necessary patches
# were not applied). The random number generator will be seeded from a file
# which is either a file pointed to by the environment valiable $RANDFILE
# or $HOME/.rnd. If neither exists, the pseudo random number generator will
# be initialized and a warning will be issued.
# Values: 0=only seed from /dev/[u]random, 1=also seed from weak randomness

#allow_weak_random_seed=1



# INCLUDE CONFIG FILE
# This directive allows you to include definitions from an external config file.

#include=<somefile.cfg>



# INCLUDE CONFIG DIRECTORY
# This directive allows you to include definitions from config files (with a
# .cfg extension) in one or more directories (with recursion).

#include_dir=<somedirectory>
include_dir=/usr/local/nagios/etc/nrpe



# COMMAND DEFINITIONS
# Command definitions that this daemon will run.  Definitions
# are in the following format:
#
# command[<command_name>]=<command_line>
#
# When the daemon receives a request to return the results of <command_name>
# it will execute the command specified by the <command_line> argument.
#
# Unlike Nagios, the command line cannot contain macros - it must be
# typed exactly as it should be executed.
#
# Note: Any plugins that are used in the command lines must reside
# on the machine that this daemon is running on!  The examples below
# assume that you have plugins installed in a /usr/local/nagios/libexec
# directory.  Also note that you will have to modify the definitions below
# to match the argument format the plugins expect.  Remember, these are
# examples only!


# The following examples use hardcoded command arguments...
#command[check_access_log]=/usr/local/libexec/check_access_log.pl -l $ARG1$ -a
#command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10
#command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20
#command[check_hda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
#command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z
#command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 150 -c 200 


# The following examples allow user-supplied arguments and can
# only be used if the NRPE daemon was compiled with support for 
# command arguments *AND* the dont_blame_nrpe directive in this
# config file is set to '1'.  This poses a potential security risk, so
# make sure you read the SECURITY file before doing this.

command[check_access_log]=/usr/local/libexec/check_access_log.pl
#command[check_users]=/usr/local/nagios/libexec/check_users -w $ARG1$ -c $ARG2$
#command[check_load]=/usr/local/nagios/libexec/check_load -w $ARG1$ -c $ARG2$
#command[check_disk]=/usr/local/nagios/libexec/check_disk -w $ARG1$ -c $ARG2$ -p $ARG3$
#command[check_procs]=/usr/local/nagios/libexec/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$

我的 sudoers 文件:

## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
##
## Examples are provided at the bottom of the file for collections
## of related commands, which can then be delegated out to particular
## users or groups.
## 
## This file must be edited with the 'visudo' command.

## Host Aliases
## Groups of machines. You may prefer to use hostnames (perhaps using 
## wildcards for entire domains) or IP addresses instead.
# Host_Alias     FILESERVERS = fs1, fs2
# Host_Alias     MAILSERVERS = smtp, smtp2

## User Aliases
## These aren't often necessary, as you can use regular groups
## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname 
## rather than USERALIAS
# User_Alias ADMINS = jsmith, mikem


## Command Aliases
## These are groups of related commands...

## Networking
# Cmnd_Alias NETWORKING = /sbin/route, /sbin/ifconfig, /bin/ping, /sbin/dhclient, /usr/bin/net, /sbin/iptables, /usr/bin/rfcomm, /usr/bin/wvdial, /sbin/iwconfig, /sbin/mii-tool

## Installation and management of software
# Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum

## Services
# Cmnd_Alias SERVICES = /sbin/service, /sbin/chkconfig

## Updating the locate database
# Cmnd_Alias LOCATE = /usr/bin/updatedb

## Storage
# Cmnd_Alias STORAGE = /sbin/fdisk, /sbin/sfdisk, /sbin/parted, /sbin/partprobe, /bin/mount, /bin/umount

## Delegating permissions
# Cmnd_Alias DELEGATING = /usr/sbin/visudo, /bin/chown, /bin/chmod, /bin/chgrp 

## Processes
# Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/kill, /usr/bin/killall

## Drivers
# Cmnd_Alias DRIVERS = /sbin/modprobe

# Defaults specification

#
# Disable "ssh hostname sudo <cmd>", because it will show the password in clear. 
#         You have to run "ssh -t hostname sudo <cmd>".
#
# Defaults    requiretty

#
# Refuse to run if unable to disable echo on the tty. This setting should also be
# changed in order to be able to use sudo without a tty. See requiretty above.
#
Defaults   !visiblepw

#
# Preserving HOME has security implications since many programs
# use it when searching for configuration files. Note that HOME
# is already set when the the env_reset option is enabled, so
# this option is only effective for configurations where either
# env_reset is disabled or HOME is present in the env_keep list.
#
Defaults    always_set_home

Defaults    env_reset
Defaults    env_keep =  "COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS"
Defaults    env_keep += "MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE"
Defaults    env_keep += "LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES"
Defaults    env_keep += "LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE"
Defaults    env_keep += "LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY"

#
# Adding HOME to env_keep may enable a user to run unrestricted
# commands via sudo.
#
# Defaults   env_keep += "HOME"

Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin

## Next comes the main part: which users can run what software on 
## which machines (the sudoers file can be shared between multiple
## systems).
## Syntax:
##
##  user    MACHINE=COMMANDS
##
## The COMMANDS section may have other options added to it.
##
## Allow root to run any commands anywhere 
root    ALL=(ALL)   ALL

## Allows members of the 'sys' group to run networking, software, 
## service management apps and more.
# %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE, DRIVERS

## Allows people in group wheel to run all commands
# %wheel    ALL=(ALL)   ALL

## Same thing without a password
# %wheel    ALL=(ALL)   NOPASSWD: ALL
user1       ALL=(ALL)   NOPASSWD: ALL
user2           ALL=(ALL)   NOPASSWD: ALL   
user3           ALL=(ALL)   NOPASSWD: ALL
nagios      ALL=(ALL)   NOPASSWD: ALL

## Allows members of the users group to mount and unmount the 
## cdrom as root
# %users  ALL=/sbin/mount /mnt/cdrom, /sbin/umount /mnt/cdrom

## Allows members of the users group to shutdown this system
# %users  localhost=/sbin/shutdown -h now

## Read drop-in files from /etc/sudoers.d (the # here does not mean a comment)
#includedir /etc/sudoers.d

# NEEDED TO ALLOW NAGIOS TO CHECK SERVICE STATUS
Defaults:nagios !requiretty
nagios ALL=NOPASSWD: /usr/local/nagios/libexec/check_init_service

# ASTERISK-SPECIFIC CHECKS
# NOTE: You can uncomment the following line if you are monitoring Asterisk locally
#nagios ALL=NOPASSWD: /usr/local/nagios/libexec/check_asterisk_sip_peers.sh, /usr/local/nagios/libexec/nagisk.pl, /usr/sbin/asterisk


# NEEDED TO ALLOW NAGIOS TO CHECK SERVICE STATUS
Defaults:nagios !requiretty
nagios ALL=NOPASSWD: /usr/local/nagios/libexec/check_init_service

# ASTERISK-SPECIFIC CHECKS
# NOTE: You can uncomment the following line if you are monitoring Asterisk locally
#nagios ALL=NOPASSWD: /usr/local/nagios/libexec/check_asterisk_sip_peers.sh, /usr/local/nagios/libexec/nagisk.pl, /usr/sbin/asterisk

感謝你的幫助。魔鬼在細節中:

command[check_access_log]=/usr/local/libexec/check_access_log.pl

需要:

command[check_access_log]=/usr/local/nagios/libexec/check_access_log.pl

您需要以與執行 NRPE 的使用者相同的使用者身份測試執行它(“nagios”,根據您的 xinetd conf)。

如果您必須以 root 身份執行這個外掛,那麼您需要設置 sudo 以便 nagios 可以在沒有密碼的情況下執行該外掛,就像您對其他外掛所做的那樣。(如果適用,請務必允許它在沒有“requiretty”的情況下執行。)

(另外,我不確定為什麼你在 sudoers 中有單獨的 nagios 命令,而且還有一個用於 nagios 的包羅萬象的 ALL/NOPASSWD 條目。這似乎很危險。)

在您確認 nagios 可以通過 sudo 執行該外掛而無需密碼後,您需要將 sudo 添加到您的命令中

$$ check_access_log $$線。

引用自:https://serverfault.com/questions/522889