nagios service check example

The time performed is specified in seconds. The plugin returns a CRITICAL state if the service is not started. Please refer tohttp://tldp.org/LDP/abs/html/untyped.html, hi! Nagios is a host and service monitor designed to inform you of network problems before your clients, end-users or managers do. Nagios can detect when services start flapping, and can suppress notifications until flapping stops and the service's state stabilizes. Sometimes I find it tricky figuring out exactly what a plugin is doing. 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. A user [emailprotected] is created in MySQL server. The daemon will listen for connections from remote clients, perform some basic validation on the results being submitted, and then write the check results directly into the external command file (as described above). A good example would be a server that is a part of an application, processing job queues using a database. 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. Active checks can be used to "poll" a device or service for status information every so often. I test the command from command line successfull, but when I insert in configuration file (cfg) it gives Error: Service check command check_http -H MYIP -u http://MYIP/test.php specified in service HTTP for host Server01 not defined anywhere! For example: nagios@nagiosserver:~/ > $ ssh-keygen -t dsa Generating public/private dsa key pair. thank you! Testing the Commands from Nagios XI Server Now we will test from the Nagios XI server that the command you just added to the NRPE client on the Linux server is working. How to handle a hobby that makes income in US. In this way, NSCA communication sent over the Internet is more secure. Why is there a voltage on my HDMI and coaxial cables? use generic-service ; Name of service template to use Apply these agent configurations After the NRDP installation, install the NCPA. For example . So I decided to use the second method. How Nagios process handles passive check results can be defined in the main Nagios configuration file. There are several different use cases covered in this KB article: The sections below provide examples of how to perform these checks using different methods. Thus, the difference between active and passive check is that active checks are run by Nagios and passive checks are run by external applications. rev2023.3.3.43278. If the situation involves reporting problems from other applications or machines, it is definitely a use case for a passive check. Filters such as firewall and TCP wrappers should be used. 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 the left navigation pane, select "Process Info" and then "Disable Notifications" and "Commit.". This defines that check_nrpe is the command and check_root_home_du is the value of $ARG1$. Nagios executes event handlers to handle hard states. 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. 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). Nagios also offers another way to work with the statuses of hosts and services. For any support related questions please visit the Nagios Support Forums at: Article Number: 775 | Rating: Unrated | Last Updated by. The next time Nagios reads the external command file it will place the results of all passive checks into a queue for later processing. $ 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. Here is another example to check CPU: nagios will indicate warning if the % cpu utilized by any process is greater than 70% and will indicate critical alert if the % cpu is greater that 80% When max_check_attempts is executed and status of the host or service is still not OK, then hard state is used. 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. This is how your host definitions look currently . Allow Nagios server to run commands on the client by adding it to the allowed_hosts entry in /etc/nagios/nrpe.cfg. Add the command to the NRPE configuration file on the client (/etc/nagios/nrpe_local.cfg): Now we can access the server and test it like any standard plugin. This means that if Nagios receives a result indicating that a host is DOWN, it assumes that all child hosts are in an UNREACHABLE state. 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. A good example of such a test is checking whether there are bad blocks on a disk. nagiosrpm. On the client host that you want to use to connect to remote Docker daemon, generate SSH keys from your user account; ssh-keygen. Nagios can tell what the status of the service is by reading the exit code of the check. Then we are removing spaces using sed and finally cut the appropriate field using cut, i this case field 5 is what we want. can nagios adjust its check time based on the status info? To turn on everything you want to set debug_level=4095. Up To: Contents How can we prove that the supernatural or paranormal doesn't exist? Edit the /usr/local/nagios/etc/objects/localhost.cfg file and add the following block: Now we are all set, the only thing pending is reloading Nagios to read the configuration files again. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? It can be used to send results from one Nagios instance to another. # Nagios Exit Codes OK=0 WARNING=1 CRITICAL=2 UNKNOWN=3 # Weather or not we can trust the exit code from the service management tool. This directive is used to perform scheduled checks of the hosts for the number you set; by default it is in minutes. It can test normal (http) and secure (https) servers, follow redirects, search for strings and regular expressions, check connection times, and report on When it comes to checking MySQL, it should be kept in mind that MySQL, by default, listens on only the loopback interface 127.0.0.1. There are many more services in Nagios which can be used to monitor pretty much anything on the running host. The check logic inside Nagios process starts the Active check. 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. This can cause problems if you are submitting passive checks from a remote host or you have a distributed monitoring setup where the parent/child host relationships are different. An example shell script of how to submit passive service check results to Nagios can be found in the documentation on volatile services. The following file can be modified to do the job. Note that all the configuration in this section is done on the client to be checked, not in the nagios server. More information on cached checks can be found here. For those unfamiliar with Nagios, it is a monitoring system which can execute checks. Service - Started Check to see if a service is started. 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. It is generally recommended to run the Nagios service check scripts in CLI before adding them to Nagios. 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). Minimum number of days a SSL certiface must be valid. In such cases, Nagios decides when a check is to be performed, runs the check and stores the result. The __HOST__ is a special service name, which represents the host check in Nagios. Submitting Passive Check Results From Remote Hosts. -c 7 -w 5 -v. Any pointer if I am missing anything but obvious. . Note: Passive host checks are normally treated as HARD states, unless the passive_host_checks_are_soft option is enabled. (1 + 2 + + 2048), Also note that your debug file will grow quickly and then rotate itself. Nagios stores the status of the hosts and services it is monitoring to determine if they are working properly or not. Passive checks are performed by external processes and the results are given back to Nagios for processing. This cant be done as an active check as reading the device takes a lot of time to completelarger disks might require several hours to complete. The best answers are voted up and rise to the top, Not the answer you're looking for? 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. Treat NRPE connection failures as 'UNKNOWN' service state, and don't notify on UNKNOWN services . But if the monitoring application is not running or some other issue prevents it from reporting, Nagios can use active checks to keep the service status upto-date. Nagios will ignore all check results for services that had not been configured before it was last (re)started. Note: A service must be defined in Nagios before you can submit passive check results for it! When services change state too frequently they are considered to be "flapping". +1 and if that seems like too much trouble you could always look at the Nagios config files to see what command and parameters need to be run. Hello, ask a question, check_http detect page size, page size detection value changes again, the alarm. 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. . Default is 10 seconds. @sunardo I just ran into this exact same thing. This can be done to gather all critical errors to a single, central place. Nonetheless, they can be tuned to match the requirements. Nagios Core is an Open Source system for monitoring hosts, networks and services. The first parameter tells Nagios that it should check whether the results from the checks are up-to-date. check_http: command not found. 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. Nagios Plugins Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. And in Puppet agent, I have to define the environment (Dev, Test or Prod). These checks help ensure that the dependency logic is as accurate as possible. Be aware that the service module is cAsE SeNsative, you can overcome this with the match= argument. ##### # Sample object config file for Nagios # # Read the documentation for more information on this configuration file. Depending on the status received on hosts and services, appropriate action is taken. 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. The host status code should be 0 for an UP state, 1 for DOWN and 2 for an UNREACHABLE state. For example: To figure this out I set nagios into debug mode with the configuration like this. More information on the flap detection logic can be found here. As this tutorial is based on Debian 9, I will show as an example how to install it, but you can find instructions for any distribution. I've deployed a new instance of Nagios on a fresh install of CentOS 7 via the EPEL repository. 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. Set enable_notifications=0 in nagios.cfg. These plugin states directly translate to service states. How can I manually run a nagios check from the command line? You'll see the following line inside the /etc/rc.d/init.d/nagios script for the Nagios startup: $NagiosBin -d $NagiosCfgFile check_command /usr/share/nagios/plugins/check_http -H MYIP -u http://MYIP/test.php, Hi, 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. 164060 Nagios HTTP/HTTPS check via wget (with/without Proxy) Check website accessibility by return code and execution time. Some of the scripts provided with Nagios are restricted to the local server only. In this tutorial, we'll install Nagios on an Ubuntu 19.10 server, but these steps should work on any Debian-based distro. Add additional tags that should be sent in the HTTP header. 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. 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. 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. Do whatever you want with a Deploying Nagios Monitoring Services on Secured Red Hat Enterprise Linux 3 Environment: fill, sign, print and send online instantly. In this tutorial, the following three servers are being used. Nagios also supports a way to monitor hosts and services passively instead of actively. Define the checks on /etc/nagios/nrpe_local.cfg. Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. It also defines Nagios user and group under which Nagios instance is running. /usr/local/nagios/libexec/check_ping -H 192.168.1.2 -w 100.0,90% -c 200.0,60% .use: Monitoring Website URL Status Furthermore , Nagios can also check whether TCP port 80 (web server) is reachable e.g., the server is online but Apache/IIS is not responding. Attributes can be used for both hosts and services. In both the cases, the idea is that Nagios receives information about host statuses over the external commands pipe. notifications_enabled 0 Rather, Nagios takes the passive check result to be the actual state the host is in and doesn't try to determine the host's actual state using the reachability logic. When the service check has completed, the child process will inform the main Nagios process (its parent) of the check results. Stop once the headers are downloaded. The following is a script that runs the dd system command (visit http://man.linuxquestions.org/index.php?query=dd) to read an entire block device. Ensure that the local file and .d directory are included in the main configuration file with: Now check one of the previously defined NRPE commands from the Nagios server: Note that the check_users NRPE command was defined in the /etc/nagios/nrpe_local.cfg file to run /usr/lib/nagios/plugins/check_users -w 5 -c 10. 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. More information on dependencies can be found here. Often, there are situations where active checks obviously fit better. NSClient++ includes a service module that can check if a service is stopped. A major difference between hosts and services is that service checks differentiate between soft and hard states. Does anyone have a working example of a dependencies.cfg file for nagios? ##### ##### # # SAMPLE SERVICE CHECK COMMANDS # # These are some example . The processing of active and passive check results is essentially identical. To use a custom script as a plugin to run remotely through NRPE, you should first write the script on the server, for instance in /usr/local/scripts/check_root_home_du.sh: The previous script is a very simple example, checking the disk usage of the directory /root and setting a threshold for considering it OK, Warning or Critical. Nagios check_udp_ports returning critical: result to scheduled check, runs fine manually, Nagios - check procs and --metric=elapsed on the same service. 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. You know the basics on Nagios administration. The results are passed to Nagios in the same way as they are passed for hosts. This usually calls for some effort. So in this blog post is all about how I used Hiera to manage the Dev,Test, Prod Stratos environments. 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. 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. This is very important in situations where a host behind a router is reported to be down because the router is actually down. If the remote server runs only HTTP and not HTTPS, youll get HTTP CRITICAL Unable to open TCP socket message as shown below. This way, Nagios can help monitor the accessibility of both MySQL servers and the database stored within the servers. Complete a blank sample electronically to These types of checks are called Passive Checks. If up-to-date information has been provided by a passive check during this period, then it will not perform active checks. I've # provided some comments here, but things may not be so clear without further # explanation, so make sure to read the HTML documentation! You can create a host file inside the server directory of Nagios and mention the host and service definitions. Also, depending on your configuration you should add this last file to the main file (/usr/local/nagios/etc/nagios.cfg): Check the configuration and, if no errors or warnings, reload the service: And now you have a new custom check on a host: Nagios has a huge library of plugins available at Nagios Exchange. Here is my configuration : It only takes a minute to sign up. Nagios will be configured to monitor SMTP and mail queue of the server. Now in your configuration for checks for a host you can create the following service check. Is it possible to check a web page through an authenticated proxy server? Giving material.angular.io a refresh from Angular Blog Medium. Detecting and dealing with state changes is what Nagios is all about. It has been designed to run . You can submit passive (means Nagios is not the inventor of the actual check commands) check results to a Nagios server instead of having the Nagios actively polling. Pass the specified string as User Agent in HTTP header. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Find the plugin you want to run (if you're not sure, compare what you see in your plugins directory on your Linux box with the plugins located here: http://exchange.nagios.org/directory/Plugins, or try running "./plugin-name -h" to get the help info about the plugin). It says -S is for version. The basic workings of service checks are described here Services are checked by the Nagios daemon: On-demand checks are performed as part of the predictive service dependency check logic. Code-GPT is an extension for VS Code that provides you instant explanations for your code within the code editor using AI. 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. Passive checks require all the logic related to what should be reported and when it should be checked to be put in an external application. Unlike with active host checks, Nagios does not (by default) attempt to determine whether or host is DOWN or UNREACHABLE with passive checks. For example, a plugin which returns a WARNING state will cause a service to have a WARNING state. How can I make Status Information for Nagios services easier to read? These checks are useful when you cannot monitor hosts/services on a regular basis. The line should look like: Define the standard checks that you will perform on every client with NRPE. This example is going to restart the crond service as it is unlikely to cause any issues. Always remember, prior to reloading Nagios, check that there are no errors in the configuration. 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. Default is 80, This will use HTTPS using default 443 port. The Nagios passive check technique described in this article uses Nagios Service Check Acceptor (NSCA) . Making statements based on opinion; back them up with references or personal experience. If a service is set up with a max_check_attempts directive of 5, then the same number of passive check results would need to be passed in order for Nagios to treat the new status as a hard state change. Get your subscription here. But if you just want to check if the instance is up and running (and not add more complexity), you can use the simple script provided here. Are there tables of wastage rates for different fruit and veg? It is possible to configure Nagios so that it will receive status information sent over a command pipe. Active checks reach out from the Nagios host and test if a service is doing what it's expected to do. With a little tweaking, Nagios can help monitor this application port as well. It is possible to monitor machine metrics, such as disk usage, CPU use, and so on. A good example might be running a check that takes several hours to completein this case, it does not make sense to raise the global service_check_timeout option, but rather to schedule these checks outside of Nagios and only report the results back to it. Note that there are possible security implications of this change, so it's worth mentioning a few words: The following tuning should do the trick. In order to make Nagios treat passive host check results in the same way as active check results, we need to enable the following option: By default, Nagios treats host results from passive checks as hard results. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? To check whether a specific webpage is available, use the -u option as shown below. The check_init_service plugin does not support checking multiple services. Check WMI Plus allows you to check multiple services, here is an example that checks for two services that are running. /usr/nagios/libexec/check_http .. Another example is where an application already processes information such as network bandwidth utilization. Nagios can tell what the status of the service is by reading the exit code of the check. Base your decision on 2 verified in-depth peer reviews and ratings, pros & cons, pricing, support and more. Check HTTPS Check whether Apache HTTPS is running on a remote server using check_http. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? There would be many cases when the failures will happen randomly and they are temporary; hence Nagios uses states to check the current status of a host or service. Nagios understands the following exit codes: If you would like to disable passive checks for just a few hosts or services, use the passive_checks_enabled directive in the host and/or service definitions to do so. # These are some example service check commands. It shows what is performed by Nagios in both cases and what needs to be done by the check command or an external application for passive checks. In such a case, adding a module that reports current utilization along with the OK/WARNING/CRITICAL state to Nagios seems much easier than using active checks for the same job. mark separates the command from the arguments in the check_command entry. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Enjoy unlimited access on 5500+ Hand Picked Quality Video Courses. 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. 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. In order to be able to submit passive check results, we need to configure Nagios to allow the sending of passive check results, and set the host objects to accept them. Consider that you have put your host definitions inside host1.cfg file in /usr/local/nagios/etc/objects directory. Installing the Nagios Remote Plugin Executor In this lab, we will install the Nagios Remote Plugin Executor on the Nagios Core Host as well as any remote hosts on which we haven't already installed it. Services are those which are used by Nagios to check something about a host. 28. Manual tuning is needed to tell MySQL to listen on other interfaces as well. Nagios check_by_ssh returns status 3 even though running the command manually works? All other servicemarks and trademarks are the property of their respective owner. If you would like to use the whole or any part of this article, you need to cite this web page at Xmodulo.com as the original source. Nagios Enterprises makes no claims or warranties as to the fitness of any file or information on this website, for any purpose whatsoever. check_http plugin is used to verify the status of HTTP server (or HTTPS) that is running on a remote host. On-demand checks are performed as part of the predictive service dependency check logic. In order to allow remote hosts to send passive check results to the monitoring host, I've developed the NSCA addon. Nagios server in this example is hosted on 192.168.0.150 and an example client is hosted on IP 192.168.0.200. Service state changes can also trigger on-demand host checks. This is the main configuration file of Nagios core. Nagios will ignore all check results for hosts that had not been configured before it was last (re)started. Nagios will still handle all notifications, event handlers, and dependencies between hosts and services. NSClient++ includes a service module that can check if a service is running. Like every Nagios plugin, you will want to check from the command line before adding it to the configuration files. Expected response string. Now let us add check_interval directive. This website is made possible by minimal ads and your gracious donation via PayPal or credit card. Follow these steps to install the plugin: Download the plugin. You can check whether a SSL certificate of the website expires within the next X number of days as shown below.