What is check_http? Nagios check_udp_ports returning critical: result to scheduled check, runs fine manually, Nagios - check procs and --metric=elapsed on the same service. Previous parts of this book often mentioned Nagios performing checks on various software and machines. It can test normal (http) and secure (https) servers, follow redirects, search for strings and regular expressions, check connection times, and report on This is how your host definitions look currently . mark separates the command from the arguments in the check_command entry. The following line is commented out to make MySQL listens on all interfaces. When you restart the Nagios, this host will start getting monitored by Nagios and the specified services will run. So in the server set the files: /usr/local/nagios/etc/objects/commands.cfg: /usr/local/nagios/etc/objects/nrpeclient.cfg: Note that the ! this is THE MOST comprehensive and straight forward turorial I've seen. vegan) just to try it, does this inconvenience the caterers and staff? 2. These will come through as an Unconfigured Object initially because Nagios XI has never received a Passive check result for this host/service. We want Nagios to monitor this database, and as the application is already using it, we can add a module that reports this to Nagios. An example shell script of how to submit passive service check results to Nagios can be found in the documentation on volatile services. Nagios Core and Nagios XI has a features to monitoring website URL status. Attributes can be used for both hosts and services. The host or the services will be tested again and again till the time the status is permanent. Architect and design WAP data flow using BigData Platform. The following illustration shows how results from active and passive checks are treated differently by Nagios: In both the cases, a check result stating that the host is down is received by Nagios. Current status from nagios Web interface: Thank you article really help a beginer like me ;-). }. When Nagios checks the status of services, it will be able to detect when a service changes between OK, WARNING, UNKNOWN, and CRITICAL states and take appropriate action. On-demand checks are performed as part of the predictive service dependency check logic. In this tutorial, the following three servers are being used. rev2023.3.3.43278. The following screenshot shows a complete overview of all the service checks that have been configured so far. Even if its parent host is currently DOWN, the child host state is also stored as DOWN. You do this with nagios -v command as root: Ensure it returns 0 errors and 0 warnings and proceed to reload the service: After reloading the service, you will see the associated check in the localhost. Nagios also offers a way of combining the benefits of both active and passive checks. I wrote a plugin in a bash script to check for current Warnings. When new information regarding a service gets passed to Nagios via the external commands pipe, Nagios treats it the same way as if it had been received by an active check. Nagios allows applications and event handlers to send out passive check results for host objects. The best answers are voted up and rise to the top, Not the answer you're looking for? Syntax and Options Format is minimum:maximum, Response time in seconds for warning state, Response time in seconds for critical state, Number of seconds to wait before connection times out. 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. 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. If youve installed Nagios from source, check_httpd command will be located in the /usr/local/nagios/libexec directory. Nagios server in this example is hosted on 192.168..150 and an example client is hosted on IP 192.168..200 Exit Codes To identify the status of a monitored service, Nagios runs a check plugin on it. Line 1 ##### 2 # Sample object config file for Nagios : 3 # 4 # Read the documentation for more information on this configuration file. $ check_http -H 192.168.1.50 HTTP OK HTTP/1.1 200 OK - 332 bytes in 0.004 seconds |time=0.004144s;;;0.000000 size=332B;;;0 2. For Nagios, many, many Oracle plugins are available for checking database availability and performance. Giving material.angular.io a refresh from Angular Blog Medium. Check WMI Plus includes a service module that can check if a service is running. The module defines a "good" service as one that is running and a "bad" service is one that is not running, so you can define critical is when more than 0 "good" services exist. I've # provided some comments here, but things may not be so clear without further # explanation, so make sure to read the HTML documentation! Learn more. Or you can create a custom variable to store the port number , with your example: Go to the Nagios interface via a web browser and log in as the nagiosadmin user. define service{ use generic-service host_name web1.onemetric.com.au service_description Uptime check_command snmp_Uptime!-C public } Adjust the commands as required. We make use of First and third party cookies to improve our user experience. This feature is only available to subscribers. 1. So I will add at the end of the file the following block:Advertisement.banner-1{text-align:center;padding-top:20px!important;padding-bottom:20px!important;padding-left:0!important;padding-right:0!important;background-color:#eee!important;outline:1px solid #dfdfdf;min-height:335px!important}if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-banner-1','ezslot_4',111,'0','0'])};__ez_fad_position('div-gpt-ad-howtoforge_com-banner-1-0');.banner-1{text-align:center;padding-top:20px!important;padding-bottom:20px!important;padding-left:0!important;padding-right:0!important;background-color:#eee!important;outline:1px solid #dfdfdf;min-height:335px!important}if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-banner-1','ezslot_5',111,'0','1'])};__ez_fad_position('div-gpt-ad-howtoforge_com-banner-1-0_1');.banner-1-multi-111{border:none!important;display:block!important;float:none!important;line-height:0;margin-bottom:7px!important;margin-left:auto!important;margin-right:auto!important;margin-top:7px!important;max-width:100%!important;min-height:250px;padding:0;text-align:center!important}. These checks help ensure that the dependency logic is as accurate as possible. System Monitoring Via Nagios and SNMP< SNMP snmp is an internet protocol that allows you to retrieve management information from a remote device or to set configuration settings on a remote device. What you are doing down is sending a Passive check result for the service SNMP Traps - Users for the host CentOS. Nagios comes with a wide range of built-in scripts for monitoring services. Up To: Contents You need to add the full path to it in the check_command. It can report each problem when accessing the database. Manual tuning is needed to tell MySQL to listen on other interfaces as well. This yields less output to dig through. Like every Nagios plugin, you will want to check from the command line before adding it to the configuration files. Now send a trap and see how the service appears as in Nagios XI. These types of checks are called Passive Checks. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. It has been designed to run . Establish a terminal session to your Nagios XI server and execute the following command: This usually calls for some effort. # yum -y install httpd gcc glibc glibc-common gd gd-devel openssl-devel net-snmp net-snmp-devel net-snmp-utils snmp* bc xinetd make wget (php php-mysql) . I'd like to use the command line to run that particular check and get the output. VS Code extension | 35 comentarios en LinkedIn One of the problems is that such checks can take only a couple of seconds to completea typical timeout for an active check to complete is 10 or 30 seconds. The object needs to have the passive_checks_enabled option set to 1 for Nagios to accept passive check results over the command pipe. 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. This directive is used to perform scheduled checks of the hosts for the number you set; by default it is in minutes. On a finishing note, Nagios can monitor many other sectors of a network. Force a check and you will see exactly how the command is being run. It says -S is for version. Sometimes I find it tricky figuring out exactly what a plugin is doing. Start Nagios Daemon Using nagios -d Typically you would execute "service nagios start" to start the Nagios daemon, which really calls the /etc/rc.d/init.d/nagios script. Start the Nagios again. Nagios is the most popular tool which is used to monitor hosts and services running in your IT infrastructure. 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. Active checks are most common in the Nagios world. Nagios can monitor different mail server components like SMTP, POP, IMAP and mailq. Consider the following script (check_warnings.sh): Based on the information provided by the nagiostats tool, I assume everything is ok if there are five or less services in Warning state.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-medrectangle-4','ezslot_1',108,'0','0'])};__ez_fad_position('div-gpt-ad-howtoforge_com-medrectangle-4-0');if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-medrectangle-4','ezslot_2',108,'0','1'])};__ez_fad_position('div-gpt-ad-howtoforge_com-medrectangle-4-0_1');.medrectangle-4-multi-108{border:none!important;display:block!important;float:none!important;line-height:0;margin-bottom:7px!important;margin-left:auto!important;margin-right:auto!important;margin-top:7px!important;max-width:100%!important;min-height:250px;padding:0;text-align:center!important}. Now that the syntax is available, TCP port 80 can be checked as follows. The Nagios Service Check Acceptor (NSCA ) addon has historically been the addon of choice for Nagios administrators that need to establish data feeds or passive check transmission between Nagios installations. Hi, thanks for your comment. Minimum number of days a SSL certiface must be valid. It also defines Nagios user and group under which Nagios instance is running. The service check runs in a child process that was fork()ed from the main Nagios daemon. There are no attachments for this article. Passive checks are initiated and performed by external applications/processes, Passive check results are submitted to Nagios for processing, Asynchronous in nature and cannot be monitored effectively by polling their status on a regularly scheduled basis, Located behind a firewall and cannot be checked actively from the monitoring host. thank you! This tutorial will cover the process of using some of these scripts for checking common services, such as MySQL, Apache web server, DNS, etc. Passive service checks are often used to report the results of long lasting tests asynchronously. How can I get it to work with https with Nagios4 and plugins 2.x? Nagios can monitor DNS service by asking the DNS server to either resolve a specific fully qualified domain name (FQDN), or by asking the server to use the dig tool. Check WMI Plus includes a service module that can check if a service is stopped. (If I were running df -h on the linux CLI, I'm using the "h" flag - in the case of the df command, the h stands for "human readable".) As with passive checks of hosts, all that is needed is to enable the global Nagios option to accept passive check results, and also enable this option for each service that should allow the passing of passive check results. Another example is where an application already processes information such as network bandwidth utilization. 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. 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 Note: Certain nodes in the above example have combined check results, such as memory/virtual, memory/swap, and processes. The next parameter specifies the number of seconds after which Nagios should consider the results to be out of date. define service{ Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? Does a summoned creature play immediately after being summoned by a ready action? Often, you have situations where other applications can report if a certain service is working properly or not. While Nagios can monitor multiple OSes, the server must reside on a Linux or Unix variant such as FreeBSD or Solaris. These are real-time graphs showing things like CPU usage, memory usage, and bandwidth. I wouldn't leave this setting on normally though, it is very verbose and fills your log file at a rapid rate. I am running into the same problem as David # Plugin commands (service and host check commands) # Arguments are likely to change between different . External applications can submit passive host check results to Nagios by writing a PROCESS_HOST_CHECK_RESULT external command to the external command file. This file location depends on the configuration you've done, in my case it is in /usr/local/nagios/etc/objects/commands.cfg. These types of checks are called Active Checks. Define the checks on /etc/nagios/nrpe_local.cfg. 03-16-2010, 10:31 AM . 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. It looks like that with the default install, theres no configuration set up to tell Icinga where to look for the check_http executable. Consider that you have put your host definitions inside host1.cfg file in /usr/local/nagios/etc/objects directory. Far better then Nagios documentation. Would you please be so kind as to help me? Another difference is that active checks require much less effort to be set up when compared to passive checks. This increases the security of the database. You might also want to give the 'capture' plugin a try. More information on dependencies can be found here. Follow these steps to install the plugin: Download the plugin. On-demand as needed for predictive service dependency checks. Making statements based on opinion; back them up with references or personal experience. The check_ncpa.py plugin enables Nagios to monitor the installed NCPAs on the hosts. The above definitions add a host called ubuntu_host and defines the services which will run on this host. Nagios, the Nagios logo, and Nagios graphics are the servicemarks, trademarks, or registered trademarks owned by Nagios Enterprises. 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! Thanks for contributing an answer to Server Fault! However, two hours after the last passive or active check result was received, Nagios would perform an active check to keep the results up-to-date. This example is going to restart the crond service as it is unlikely to cause any issues. How Nagios process handles passive check results can be defined in the main Nagios configuration file. If the situation involves reporting problems from other applications or machines, it is definitely a use case for a passive check. (In this example, the script will print All ok and it will exit with 0, the OK . Nagios also offers a tool for sending passive check results for hosts and services over a network. If an application that resides on the same host as Nagios is sending passive host or service check results, it can simply write the results directly to the external command file as outlined above. Let us see an example to perform checks on host . Nagios Enterprises makes no claims or warranties as to the fitness of any file or information on this website, for any purpose whatsoever. The check logic inside Nagios process starts the Active check. The key features of passive checks are as follows: The major difference between active and passive checks is that active checks are initiated and performed by Nagios, while passive checks are performed by external applications. 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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). Default is 10 seconds. Services are those which are used by Nagios to check something about a host. Here is how it can be done. Active checks can be used to "poll" a device or service for status information every so often. All of the scripts are located at /etc/nagios-plugins/config/ with the executable files stored at /usr/lib/nagios/plugins/. By default, Nagios handles results from active and passive checks differently. check_http -H hostname (or) -I ip-address {optional options}. ##### ##### # # SAMPLE SERVICE CHECK COMMANDS # # These are some example . Use Puppet environments. Always remember, prior to reloading Nagios, check that there are no errors in the configuration. This is the main configuration file of Nagios core. Why is there a voltage on my HDMI and coaxial cables? Far better then Nagios documentation. Let us see an example to perform checks on host Consider that you have put your host definitions inside host1.cfg file in /usr/local/nagios/etc/objects directory. It allows to configure alerts and has different states for them. Some of the scripts provided with Nagios are restricted to the local server only. The script should then post results to the Nagios daemon. These checks can provide useful insight on what is going on within the Nagios server. Complete a blank sample electronically to Default is 80, This will use HTTPS using default 443 port. This command accepts the host name, status code, and the textual output from a check. Host is just like a computer; it can be a physical device or virtual. A sample definition for a host that runs an active check if there has been no result provided within the last two hours: The following is an illustration showing when Nagios would invoke active checks: Each time there is at least one passive check result that is still valid (i.e., was received within the past two hours), Nagios will not perform any active checks. Remember to allow the execution of the script: if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-box-4','ezslot_6',110,'0','0'])};__ez_fad_position('div-gpt-ad-howtoforge_com-box-4-0'); The result is a text message and an exit code: This step will be the same with your own plugins, and if you download a third-party plugin from the internet as well. Check whether Apache HTTPS is running on a remote server using check_http. Nagios can detect when services start flapping, and can suppress notifications until flapping stops and the service's state stabilizes. Related Commands. http://www.waggy.at/nagios/capture_plugin.htm, Go to your plugin directory - in my example it is, Type you plugin name - in my example it is, now run the full command - (plugin name) -H (hostname) -p (port number), However in this example port number is optional, in your config file which is look something like below (myserver.cfg) and you want to run check_cpu from command line, to check instantly (without GUI green or red), Try this - (plugin full path) - H (servername) -c (checkname).