1. NRPENagios Remote Plugin ExecutorMike Webermweber@spidertools.com

2. NRPE ConceptsAgent Required on Client* plugin or script executes locally* daemon runs on client (port 5666)Nagios* check_nrpe connects to clientDirect Checks* connect and collect data from clientIndirect Checks* connect to client, execute plugin to connect to second client20122 3. Basic Concepts 2012 3 4. NRPE: Active and Indirect Checks2012 4 5. NRPE Components: Client NRPE Daemon * daemon managed by xinetd * security based on allowed_hosts * runs on port 5666 * open firewall NRPE Commands File (nrpe.cfg) * check_nrpe connects to client * command definitions Plugins * connect and collect data from client 2012 5 6. NRPE Components: ServerOne Plugin* check_nrpe (installed by default in XI)Host and Service Definitions* define the host* define each service 2012 6 7. NRPE Variables 8. NRPE Variables: Client Agent Install * repository (CentOS, SUSE,Ubuntu, Debian, etc.) * XI agent from wizard * compile Daemon Install * repository (CentOS, SUSE,Ubuntu, Debian, etc.) * compile nrpe.cfg * repository (CentOS, SUSE,Ubuntu, Debian, etc.) * compile Command Definitions 2012 8 9. Client Variables: Daemon and Config Program /usr/local/nagios/bin/nrpe /usr/sbin/nrpe Daemon Config /etc/xinet.d/nrpe /etc/nagios/nrpe /etc/nagios3/nrpe (Ubuntu)2012 9 10. NRPE: Daemon Config - 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= 127.0.0.1 192.168.5.99}2012 10 11. Client Variables: Commands File Location /usr/local/nagios/etc/nrpe.cfg (compile) /usr/local/nagios/etc/nrpe/common.cfg (XI Agent) /etc/nagios/nrpe.cfg (SUSE) /etc/nagios3/nrpe.cfg (Ubuntu) Definitions * able to use arguments * dont_blame_nrpe=1 command[check_users]=/usr/local/nagios/libexec/check_users -w $ARG1$ -c $ARG2$ * unable to use arguments * dont_blame_nrpe=0 command[check_users]=/usr/local/nagios/libexec/check_users -w 2 -c 4 2012 11 12. Client Variables: Plugins Location /usr/local/nagios/libexec /usr/lib/nagios/plugins /usr/lib64/nagios/plugins 201212 13. NRPE Compile 14. Why Compile NRPE and Plugins? Eliminate Variables Across Distribution * same daemon settings and location * same nrpe definitions * same commands locations and configuration (nrpe.cfg) * same location for plugins * same versions Uniform Troubleshooting * standards across distributions * easier for multiple administrators Uniform Upgrades * method of upgrade the same * upgrades will be the latest201214 15. NRPE: Install Script#!/bin/bashif [[ $EUID -ne 0 ]]; then echo "This script must be run as root" 1>&2 exit 1ficd /tmpwget http://sourceforge.net/projects/nagios/files/nrpe-2.x/nrpe-2.13/nrpe-2.13.tar.gz/downloadtar zxvf nrpe-2.13.tar.gzcd nrpe-2.13yum install -y mod_ssl openssl-devel xinetd gcc make./configure --with-ssl=/usr/bin/openssl --with-ssl-lib=/usr/libmakemake installmake install-daemonmake install-daemon-configmake install-xinetdcp sample-config/nrpe.cfg /usr/local/nagios/etc/ 201215 16. Plugins: Install Script#!/bin/bashif [[ $EUID -ne 0 ]]; then echo "This script must be run as root" 1>&2 exit 1ficd /tmpwget http://sourceforge.net/projects/nagiosplug/files/nagiosplug/1.4.16/nagios-plugins-1.4.16.tar.gz/downloadyum install -y gcc make mysql-devel mysql net-snmpuseradd nagiosgroupadd nagcmdusermod -a -G nagcmd nagiostar zxvf nagios-plugins-1.4.16.tar.gzcd nagios-plugins-1.4.16./configure --with-nagios-user=nagios --with-nagios-group=nagiosmakemake installexit 0 2012 16 17. NRPE: Locations When Compiled Daemon Configuration /etc/xinetd.d/nrpe Daemon Binary /usr/local/nagios/bin/nrpe Configuration File /usr/local/nagios/etc/nrpe.cfg Plugins /usr/local/nagios/libexec2012 17 18. NRPE: XI Agent 19. CentOS Agent: XIcd /tmpwget http://assets.nagios.com/downloads/nagiosxi/agents/linux-nrpe-agent.tar.gztar zxvf linux-nrpe-agent.tar.gzcd linux-nrpe-agent./fullinstallAllow from: 192.168.5.184Stopping xinetd:[ OK ]Starting xinetd:[ OK ]Subcomponents installed OKRESULT=0################################################################### Nagios XI Linux Agent Installation Complete! ###################################################################201219 20. NRPE: Locations XI Agent Daemon Configuration /etc/xinetd.d/nrpe Daemon Binary /usr/local/nagios/bin/nrpe Configuration File /usr/local/nagios/etc/nrpe.cfg include_dir=/usr/local/nagios/etc/nrpedont_blame_nrpe=1 /usr/local/nagios/etc/nrpe/common.cfg Plugins /usr/local/nagios/libexec201220 21. common.cfg### GENERIC SERVICES ###command[check_init_service]=sudo /usr/local/nagios/libexec/check_init_service $ARG1$command[check_services]=/usr/local/nagios/libexec/check_services -p $ARG1$### MISC SYSTEM METRICS ####command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10command[check_users]=/usr/local/nagios/libexec/check_users $ARG1$command[check_load]=/usr/local/nagios/libexec/check_load $ARG1$command[check_swap]=/usr/local/nagios/libexec/check_swap $ARG1$command[check_cpu_stats]=/usr/local/nagios/libexec/check_cpu_stats.sh $ARG1$command[check_mem]=/usr/local/nagios/libexec/custom_check_mem $ARG1$### YUM UPDATES ###command[check_yum]=/usr/local/nagios/libexec/check_yum### DISK ###command[check_disk]=/usr/local/nagios/libexec/check_disk $ARG1$command[check_ide_smart]=/usr/local/nagios/libexec/check_ide_smart $ARG1$### PROCESSES ###command[check_all_procs]=/usr/local/nagios/libexec/custom_check_procscommand[check_procs]=/usr/local/nagios/libexec/check_procs $ARG1$### OPEN FILES ###command[check_open_files]=/usr/local/nagios/libexec/check_open_files.pl $ARG1$### NETWORK CONNECTIONS ###command[check_netstat]=/usr/local/nagios/libexec/check_netstat.pl -p $ARG1$ $ARG2$ 201221 22. Commands: nrpe.cfgNo Variables Alloweddont_blame_nrpe=0command command[check_hda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1Using Variablesdont_blame_nrpe=1command command[check_hda1]=/usr/local/nagios/libexec/check_disk -w $ARG1$ -c $ARG2$ -p$ARG3$201222 23. Downside of Arguments CentOS check_cpu_stats!-a -w 85 -c 95 SUSE Enterprise check_cpu_stats!-a -w 80 -a -c 90 2012 23 24. NRPE: Nagios Core 25. NRPE: Active Check 2012 25 26. Nagios Core: Service ChecksNo Argumentsdefine service{ use generic-service host_name centos service_description Users check_commandcheck_nrpe!check_users }define service{ use generic-service,srv-pnp host_name centos service_description Mailq check_command check_nrpe!check_mailq }Argumentsdefine service{ use generic-service host_name centos service_description Disk check_command check_nrpe_arg!check_disk!80!90!/} 201226 27. Nagios Core: Command DefinitionNo Argumentsdefine command{ command_namecheck_nrpe command_line$USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$}define command{ command_namecheck_nrpe_60 command_line$USER1$/check_nrpe -H $HOSTADDRESS$ -t 60 -c $ARG1$}Argumentsdefine command{ command_namecheck_nrpe_arg command_line$USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$ -a$ARG2$ $ARG3$ $ARG4$}201227 28. SummaryNo Argumentsdefine command{ command_namecheck_nrpe command_line$USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$}define service{ use generic-service host_name centos service_description Users check_command check_nrpe!check_users }command[check_users]=/usr/local/nagios/libexec/check_users -w 2 -c 4Argumentsdefine command{ command_name check_nrpe_arg command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$ -a $ARG2$$ARG3$ $ARG4$}define service{ usegeneric-service host_namecentos service_descriptionDisk check_commandcheck_nrpe_arg!check_disk!80!90!/}command[check_disk]=/usr/local/nagios/libexec/check_disk $ARG1$ 2012 28 29. AIDE: Advanced Intrusion Detection EnvironmentScript!/bin/bash# Create 4 Hour Cron Job With AIDElogfile=/tmp/aidex=$(grep "Looks okay" $logfile | wc -l)if [ $x -eq 1 ]then echo "All Systems Look OK" stateid=0else echo "$(egrep "added|changed" /tmp/aide)" stateid=2fiexit $stateidCommand in nrpe.cfgcommand[check_aide]=/usr/local/nagios/libexec/check_aideService Definitiondefine service{ usegeneric-service host_name bash service_description AIDE check_command check_nrpe!check_aide } 201229 30. NRPE: Nagios XI 31. NRPE: Linux Server 2012 31 32. NRPE: Linux Server 2012 32 33. NRPE: Linux Server 2012 33 34. NRPE: Linux Server 2012 34 35. NRPE: Linux Server 2012 35 36. /etc/init.dls /etc/init.dcrondgpm iscsilvm2-monitor named nscdrawdevicessnmpd sysstatdc_clienthaldaemoniscsidmcstrans netconsolentpd rdisc snmptrapdvsftpd dc_server halt killallmessagebus netfs portmaprestorecondsnmpttwinbinddovecothttpdkudzu multipathd netplugdpostfixsaslauthd sshdxinetd functions iptables lm_sensors mysqldnetwork postgresql-9.0single syslog201236 37. NRPE: Linux Server 2012 37 38. NRPE: Linux Server 2012 38 39. NRPE: Linux Server 2012 39 40. NRPE: Linux Server 2012 40 41. NRPE: Additional Checks 2012 41 42. NRPE: Additional Checks 2012 42 43. NRPE: Additional Checks 2012 43 44. NRPE: Questions?