To figure this out I set nagios into debug mode with the configuration like this. To allow it to grow bigger before rotating, add more zeroes, for example. In the following example, we are checking whether the website certificate expires in the next 365 days. By default Nagios supports URL monitoring and there is an command check_http, however if you want to monitor URL like SSL certification you can also do by extending the command options. In fact, we officially. It can test normal (http) and secure (https) servers, follow redirects, search for strings and regular expressions, check connection times, and report on The plugin returns a CRITICAL state if the service is not started. When services change state too frequently they are considered to be "flapping". When a passive result check comes in to Nagios, Nagios expects that the result already has a network topology included. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? Passive service checks are often used to report the results of long lasting tests asynchronously. Let us see an example to perform checks on host . Another example is where an application already processes information such as network bandwidth utilization. Nagios Plugins Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. Nagios will ignore all check results for hosts that had not been configured before it was last (re)started. Syntax and Options These checks are scripts and progams which take input (for example, which host to check, tresholds), do a check and then return an exit code and some performance data. When the service check has completed, the child process will inform the main Nagios process (its parent) of the check results. On a finishing note, Nagios can monitor many other sectors of a network. See Also: Active Checks, Host Checks, Check Scheduling, Predictive Dependency Checks. Using the definition below, checks on the host will be performed after every 3 minutes. The files and information on this site are the property of their respective owner(s). Hi, thanks for your comment. Viewed 12725 times since Tue, Nov 14, 2017, Viewed 18667 times since Tue, Nov 28, 2017, Viewed 70502 times since Thu, Nov 9, 2017, Viewed 9709 times since Tue, Nov 14, 2017, Viewed 12197 times since Wed, Nov 29, 2017, Viewed 47389 times since Thu, Nov 9, 2017, Viewed 14647 times since Sun, Nov 26, 2017, Viewed 42173 times since Mon, Nov 13, 2017, Viewed 18034 times since Wed, Nov 15, 2017, Viewed 22586 times since Sun, Nov 26, 2017. Line 1 ##### 2 # Sample object config file for Nagios : 3 # 4 # Read the documentation for more information on this configuration file. The following file can be modified to do the job. Method 3. Enjoy unlimited access on 5500+ Hand Picked Quality Video Courses. Up To: Contents See the HTML : 45 ##### ##### # # SAMPLE SERVICE CHECK COMMANDS # # These are some example . And in Puppet agent, I have to define the environment (Dev, Test or Prod). To identify the status of a monitored service, Nagios runs a check plugin on it. If I used the first method, I have to keep separate site.pp for each environment. Now that the syntax is available, TCP port 80 can be checked as follows. On-demand as needed for predictive service dependency checks. You might also want to give the 'capture' plugin a try. It allows to configure alerts and has different states for them. We can also configure Nagios so that if no new information has been provided within a certain period of time, it will use active checks to get the current status of the host or service. This task is really easy as Nagios has a built-in command for this. There are no attachments for this article. In cases where the checks require the deployment of long-running processes or monitoring information constantly, this should be done as a passive service. It has been designed to run . Repeat this procedure for each Ceph plug-in applicable to the node. As with submitting host check results, it is worth mentioning that Nagios will take some time to process passive check results as they are polled periodically from the external commands pipe. If up-to-date information has been provided by a passive check during this period, then it will not perform active checks. I take a slightly more brute-force direction than @Zoredache, I login to the nagios server and do "while true; do ps awwlx | grep NAGIOS_CHECK_NAME; done", while I force a re-check of the service, where NAGIOS_CHECK_NAME is either part of the check name or the IP of the server I am looking for. However, applications on remote hosts can't do this so easily. Agree If the situation involves reporting problems from other applications or machines, it is definitely a use case for a passive check. It says Unknown option specified in config file , check_http -I 10.0.0.76 -p 8192 url=/MYServiceBus/ post= eregi=.Status_Code.0./Status_Code. In general, if a check can be done quickly and does not require long running processes, it should definitely be done as an active service. Here is how it can be done. When it comes in as a passive check, no state translation is done and Nagios stores the host and all child nodes being down. awesome. Fortra's Intermapper vs Kaseya Traverse: which is better? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. The method for using any of these "plugins" from the command line is the same as any other Linux script: Just run "./plugin-name" with the appropriate flags you want to check, and voila! command line output while running with -S is check_http: Invalid option SSL is not available, Next post: UNIX / Linux whatis Command Examples, Previous post: UNIX / Linux split Command Examples, Home | Linux 101 Hacks Table of Contents | Contact | Email | RSS | Copyright 20092022 Ramesh Natarajan All rights reserved | Terms of Service, host name of the server where HTTP (or HTTPS) daemon is running, Port number where HTTP server runs. You can check tomcat server, or apache server, or glassfish, or any server that is running on a different port by speficying the port number as shown below. I've deployed a new instance of Nagios on a fresh install of CentOS 7 via the EPEL repository. In order to do this, we need to enable active checks by setting the active_checks_enabled option to 1 without specifying the normal_check_interval directive. The results are passed to Nagios in the same way as they are passed for hosts. . Or you can create a custom variable to store the port number , with your example: In order to enable passive checks in Nagios, you'll need to do the following: If you want to disable processing of passive checks on a global basis, set the accept_passive_service_checks directive to 0. Note: Certain nodes in the above example have combined check results, such as memory/virtual, memory/swap, and processes. @sunardo I just ran into this exact same thing. After installing nagios and nagios-plugins-all (via yum), I've c. Enable and restart the nrpe service: [user@mon]# systemctl enable nrpe [user@mon]# systemctl restart nrpe. You can create a host file inside the server directory of Nagios and mention the host and service definitions. All of the scripts are located at /etc/nagios-plugins/config/ with the executable files stored at /usr/lib/nagios/plugins/. On the client host that you want to use to connect to remote Docker daemon, generate SSH keys from your user account; ssh-keygen. NSCA stands for Nagios Service Check Acceptor. A major difference between hosts and services is that service checks differentiate between soft and hard states. Some of the scripts provided with Nagios are restricted to the local server only. Indicate content type in header for POST request, Regular expression can span to new line (Use this with -r or -R option), Use this regular expression to search for string in the HTTP page, If the site user basic authentication send uid, pwd in the format uid:pwd. Does anyone have a working example of a dependencies.cfg file for nagios? The NRDP addon allows administrators to migrate from using NSCA to NRDP fairly easily. Often, there are situations where active checks obviously fit better. For instance, a model for the file could be: The idea of having that generic file is so that you can check the same on every client. great! This is how your host definitions look currently . The plugin can only check if the service is started, you could however use the negate plugin to invert the returned result from the plugin (hence making "stopped" have an OK state). These checks are useful when you cannot monitor hosts/services on a regular basis. Simple invoke the command with -s parameter and the name of the service Example of use ./check_service -s ntpd Thank you! Host is just like a computer; it can be a physical device or virtual. For example: First, the servers are defined in Nagios. In the left navigation pane, select "Process Info" and then "Disable Notifications" and "Commit.". The following figure shows soft states and hard states. To check whether a specific webpage is available, use the -u option as shown below. Services are checked by the Nagios daemon: At regular intervals, as defined by the check_interval and retry_interval options in your service definitions. These are executed on regular intervals, as defined by check_interval and retry_interval. Scheduled service checks are run in parallel. It can also be used by third-party applications running on different machines to send passive check results to a central Nagios server. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Monthly digest of what's new and exciting from us. This file location depends on the configuration you've done, in my case it is in /usr/local/nagios/etc/objects/commands.cfg. Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. Active checks can be used to "poll" a device or service for status information every so often. This can be done in addition to active checks, to identify critical problems earlier. The script should then post results to the Nagios daemon. The object file localhost.cfg allows for parameters to be passed to check_ssh. I will leave this script with all the other Nagios plugins inside /usr/local/nagios/libexec/ (This directory may be different depending on your confiugration). You know the basics on Nagios administration. Treat NRPE connection failures as 'UNKNOWN' service state, and don't notify on UNKNOWN services . Unlike with active host checks, Nagios does not (by default) attempt to determine whether or host is DOWN or UNREACHABLE with passive checks. It is vital to make sure only legitimate networks have access to the database. This way, the other applications on your Nagios server can report the status of the hosts. You can define service execution dependencies that prevent Nagios from checking the status of a service depending on the state of one or more other services. Copy the configuration file to the Apache directory: /usr/bin/install -c -m 644 sample-config/httpd.conf /etc/apache2/sites-available/nagios.conf Install the Nagios Plugins to have a set of tools to monitor your different services: apt install build-essential libssl-dev gcc 03-16-2010, 10:31 AM . Plugin then gets executed on the remote machine where is collects the required information and sends then back to Nagios daemon. The files and information on this site are the property of their respective owner(s). What you are doing down is sending a Passive check result for the service SNMP Traps - Users for the host CentOS. How to Write a Custom Nagios Check Plugin, /usr/local/nagios/etc/objects/commands.cfg, /usr/local/nagios/etc/objects/localhost.cfg, /usr/lib/nagios/plugins/check_users -w 5 -c 10, /usr/local/nagios/etc/objects/nrpeclient.cfg, Generic installation on Debian-based Client, Set the NRPE Check on the Server Configuration Files, Develop Network Applications for ESP8266 using Mongoose in Linux, How to Setup IKEv2 IPSec VPN Using strongSwan and Let's Encrypt on Rocky Linux 9, ISPConfig Perfect Multiserver setup on Ubuntu 20.04 and Debian 10, Generating Web Site Statistics With AWStats & JAWStats On Debian Lenny, How to Install Jitsi Video Conference Platform on Debian 11, How to Install LAMP Server Stack on Ubuntu 22.04, How to use grep to search for strings in files on the Linux shell, You have Nagios installed and running (You can follow this. When Nagios needs to run a scheduled service check, it will initiate the service check and then return to doing other work (running host checks, etc). The host or the services will be tested again and again till the time the status is permanent. Making statements based on opinion; back them up with references or personal experience. As mentioned earlier, server-2 has postfix mail server set up on it. If you want know more, just read and play with: I'm new to shell and would like to understand and adapt your script would you comment on why this particular adaptation wont work (results unknown - 0 regardless of input parameter sent by the user), countWarnings=$(/usr/local/nagios/bin/nagiostats | grep "Ok/Warn/Unk/Crit:" | sed 's/[[:space:]]//g' | cut -d"/" -f5), echo "example: plugin.sh minimal_counter_for_warning_alert counter_for_critical_alert", if (($warn<=$countWarnings ||$countWarnings==0)); then, echo "OK - $countWarnings services in Warning state", elif (($warn<$countWarnings && $countWarnings<=$crit)); then, echo "WARNING - $countWarnings services in Warning state", echo "CRITICAL - $countWarnings services in Warning state", [emailprotected]:/usr/local/nagios/libexec$ echo $(/usr/local/nagios/bin/nagiostats | grep "Ok/Warn/Unk/Crit:" | sed 's/[[:space:]]//g' | cut -d"/" -f5). Learn more. use generic-service ; Name of service template to use Often, you have situations where other applications can report if a certain service is working properly or not. Would you please be so kind as to help me? However, if there are no jobs to process and the application is not using it, Nagios will not have up-to-date information about the database. Default is 10 seconds. An external application checks the status of a host or service. In such cases, only reports regarding hard state changes are propagated across Nagios servers. Do not wait for whole document body to download. When you restart the Nagios, this host will start getting monitored by Nagios and the specified services will run. We can also do it at a contact level, by disabling notifications . you have the flexibility of sending the passive check to Nagios with a different hostname. This tutorial will cover the process of using some of these scripts for checking common services, such as MySQL, Apache web server, DNS, etc. Server Fault is a question and answer site for system and network administrators. We make use of First and third party cookies to improve our user experience. It's pretty simple. This is where the location of Nagios log file, status.dat file, lock file and host and services state update interval is defined. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Define the checks on /etc/nagios/nrpe_local.cfg. Service or Daemon checks are system processes that run in the background, usually configured to start when the system boots. Remember that the $USER1$ variable, is a local Nagios variable set in the resource.cfg file, in my case pointing to /usr/local/nagios/libexec. The following settings are done for all MySQL servers. # SAMPLE HOST CHECK . As mentioned earlier, Nagios can forgo the actual execution of an on-demand service check if it can use the cached results from a relatively recent service check. Base your decision on 2 verified in-depth peer reviews and ratings, pros & cons, pricing, support and more. The example contains partial output. This website is made possible by minimal ads and your gracious donation via PayPal or credit card. These checks help ensure that the dependency logic is as accurate as possible. The main Nagios process then handles the check results and takes appropriate action (running event handlers, sending notifications, etc.). Select check_cluster from the plugin pop-up menu. Thanks for contributing an answer to Server Fault! It is generally recommended to run the Nagios service check scripts in CLI before adding them to Nagios. Allow Nagios server to run commands on the client by adding it to the allowed_hosts entry in /etc/nagios/nrpe.cfg. I don't know if it's best practice or not , but i would declare count Warnings as an integer variable when doing arithmetic operations. Usually within a few seconds the full check command pops up and I then kill the while loop and run the check command. Force a check and you will see exactly how the command is being run. Attributes can be used for both hosts and services. This can be done to gather all critical errors to a single, central place. Note: Passive host checks are normally treated as HARD states, unless the passive_host_checks_are_soft option is enabled. Is there a proper earth ground point in this switch box? The default FQDN used for testing is www.google.com, but it can be changed as needed. Once the host and services are configured on Nagios, checks are used to see if the hosts and services are working as they are supposed to or not. this is THE MOST comprehensive and straight forward turorial I've seen. The NSCA addon consists of a daemon that runs on the Nagios hosts and a client that is executed from remote hosts. How to handle a hobby that makes income in US. It also defines Nagios user and group under which Nagios instance is running. The following is a sample script that will accept the host name, status code, and output from a check and will submit these to Nagios: As an example of the use of this script, the command that is sent to Nagios for host01, status code 2 (UNREACHABLE) and output router 192.168.1.2 down would be as follows: When submitting results, it is worth noting that Nagios might take some time to process them, depending on the intervals between Nagios checks of the external command pipe. Nagios can monitor different mail server components like SMTP, POP, IMAP and mailq. Nagios can tell what the status of the service is by reading the exit code of the check. Check WMI Plus includes a service module that can check if a service is running. Nagios understands the following exit codes: A program can be written in any language to work as a Nagios check plugin. Depending on the status received on hosts and services, appropriate action is taken. Monitoring Website URL Status They are a web interface and command line tool set to work with Nagios config that have decent default templates and "example" files that you can leverage for common checks. In this way, NSCA communication sent over the Internet is more secure. When a host or service is down for a very short duration of time and its status is not known or different from previous one, then soft states are used. By using this website, you agree with our Cookies Policy. NSClient++ allows you to check multiple services, here is an example that checks for two services that are running. For example, if you are bringing down your HTTP server everyday sometime between midnight and 1:59 a.m, you can specify the above "247-except-night-12-2" timeperiod in your service definition for the check_period and notification_period as shown below for your particular service definition. Enter file in which to save the key (/home/nagios/.ssh/id_dsa): Enter passphrase (empty for. Get your subscription here. I wrote a plugin in a bash script to check for current Warnings. To keep the article focused on service monitoring, we will not be configuring hostgroups or templates, as they have been covered in the previous tutorial. # Sample object config file for Nagios : 3 # 4 # Read the documentation for more information on this configuration file. can nagios adjust its check time based on the status info? Submitting Passive Host Check Results External applications can submit passive host check results to Nagios by writing a PROCESS_HOST_CHECK_RESULT external command to the external command file.