nagios service check example nagios service check example

Check whether Apache HTTPS is running on a remote server using check_http. Yeah, it's totally brute-force, but it works for me. A major difference between hosts and services is that service checks differentiate between soft and hard states. NPCA includes a service module that can check if a service is running. In most cases you'll use Nagios to monitor your hosts and services using regularly scheduled active checks. This file location depends on the configuration you've done, in my case it is in /usr/local/nagios/etc/objects/commands.cfg. Nagios check service frequency based on service status, how can execute nagios commands from command line in linux. This yields less output to dig through. Here is how it can be done. This increases the security of the database. On a finishing note, Nagios can monitor many other sectors of a network. 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. How to use it? Establish a terminal session to your Nagios XI server and execute the following command: i'm very new on that kind of progamming what does this line ", " means i really want to lear some but i need help please helpme. Submitting passive host check results to Nagios requires sending a command to the Nagios external command pipe. Nagios provides a sample configuration file, that we will use. Always remember, prior to reloading Nagios, check that there are no errors in the configuration. Services that are checked can be in one of four different states: Service checks are performed by plugins, which can return a state of OK, WARNING, UNKNOWN, or CRITICAL. service_description check http://MYIP/test.php If I used the first method, I have to keep separate site.pp for each environment. Nagios also offers a tool for sending passive check results for hosts and services over a network. Are there tables of wastage rates for different fruit and veg? Stats Graphs - Live data graphs of CPU, memory, interface bandwidth, and disk usage. Now send a trap and see how the service appears as in Nagios XI. check_command /usr/share/nagios/plugins/check_http -H MYIP -u http://MYIP/test.php, Hi, Plugin then gets executed on the remote machine where is collects the required information and sends then back to Nagios daemon. Usually within a few seconds the full check command pops up and I then kill the while loop and run the check command. Nagios server in this example is hosted on 192.168.0.150 and an example client is hosted on IP 192.168.0.200. 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. This usually calls for some effort. The flexibility provided by Nagios is perfect for these case scenarios. 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. Some methods support checking multiple services at once. Why is there a voltage on my HDMI and coaxial cables? Nagios: Simple Oracle Check. I've deployed a new instance of Nagios on a fresh install of CentOS 7 via the EPEL repository. Does a summoned creature play immediately after being summoned by a ready action? 2022 Company, Inc. All rights reserved. Check WMI Plus allows you to check multiple services, here is an example that checks for two services that are running. check_http: command not found. 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. Fortra's Intermapper vs Kaseya Traverse: which is better? 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. By using this website, you agree with our Cookies Policy. 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. Hi, this is a fantastic article, i managed to learn how to make plugins myself. So I decided to use the second method. Asking for help, clarification, or responding to other answers. Primary Vendor -- Product Description Published CVSS Score Source & Patch Info; akamai -- cloudtest: Akamai CloudTest before 58.30 allows remote code execution. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. rev2023.3.3.43278. To monitor hosts and services running on remote machines, Nagios executes plugins and tells what information to collect. For Nagios, many, many Oracle plugins are available for checking database availability and performance. 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. The figure shown below shows an active check . The host or the services will be tested again and again till the time the status is permanent. 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. Please refer tohttp://tldp.org/LDP/abs/html/untyped.html, hi! When a host is reported to be DOWN as a passive check result, Nagios does not perform a translation from DOWN to UNREACHABLE. 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. Save my name, email, and website in this browser for the next time I comment. This way, Nagios can help monitor the accessibility of both MySQL servers and the database stored within the servers. You know the basics on Nagios administration. External applications can submit passive host check results to Nagios by writing a PROCESS_HOST_CHECK_RESULT external command to the external command file. Be aware that the service module is cAsE SeNsative, you can overcome this with the match= argument. 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. Some of the scripts provided with Nagios are restricted to the local server only. Scheduled service checks are run in parallel. 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. 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. 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. 2. check_http plugin is used to verify the status of HTTP server (or HTTPS) that is running on a remote host. An example shell script of how to submit passive service check results to Nagios can be found in the documentation on volatile services. nagiostats provides statistics of which only the part `Services Ok/Warn/Unk/Crit: 8 / 0 / 0 / 0` are interesting to us, so we are using grep to extract this line. For Nagios to perform active checks when there is no up-to-date result from passive checks, you need to set the check_freshness directive to 1 and set freshness_threshold to the time period after which a check should be performed. In such cases, Nagios decides when a check is to be performed, runs the check and stores the result. The plugin returns a CRITICAL state if the service is not started. The check logic inside Nagios process starts the Active check. 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. Nagios's primary mode of "service checking" is called an active check. /usr/nagios/libexec/check_http .. 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. 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. NSCA stands for Nagios Service Check Acceptor. define service{ Pass the specified string as User Agent in HTTP header. It allows to configure alerts and has different states for them. The following is an example of the required configuration for a host that accepts passive checks and has active checks disabled: Configuring services is exactly the same as with hosts. 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). 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. 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. # SAMPLE HOST CHECK . (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".) 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. 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. In order to allow remote hosts to send passive check results to the monitoring host, I've developed the NSCA addon. Nagios can check whether the server is online by running ping on the IP/name of the server as well as it can be set up to provide warnings in case the round trip time (RTT) to the server increases. 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. Check HTTPS Check whether Apache HTTPS is running on a remote server using check_http. $ 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. thank you! Expected response string. If youve installed Nagios from source, check_httpd command will be located in the /usr/local/nagios/libexec directory. Nagios will still handle all notifications, event handlers, and dependencies between hosts and services. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? Set enable_notifications=0 in nagios.cfg. 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. 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. Now in your configuration for checks for a host you can create the following service check. This mechanism includes password protection, along with encryption, to prevent injection of false results in to Nagios. i.e: This user is then granted all permission to all databases and will be used for monitoring. 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. This task is really easy as Nagios has a built-in command for this. It says -S is for version. Nagios stores the status of the hosts and services it is monitoring to determine if they are working properly or not. Nagios check_udp_ports returning critical: result to scheduled check, runs fine manually, Nagios - check procs and --metric=elapsed on the same service. Is it possible to check a web page through an authenticated proxy server? -c 7 -w 5 -v. Any pointer if I am missing anything but obvious. Even if its parent host is currently DOWN, the child host state is also stored as DOWN. 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. Use 5 for 5 seconds, 5m for 5 minutes, 5h for 5 hours, 5d for 5 days. Passive checks are also used when configuring distributed or redundant monitoring installations. More information on how this works can be found here. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Last updated on September 22, 2020 by Sarmed Rahman. Nagios comes with a wide range of built-in scripts for monitoring services. Giving material.angular.io a refresh from Angular Blog Medium. 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. This should enable MySQL to listen on all interfaces, as well as accept incoming connections from user nagios at any host. 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. The figure shown below shows a passive check . In the following example, we are checking whether the website certificate expires in the next 365 days. . External applications can submit passive service check results to Nagios by writing a PROCESS_SERVICE_CHECK_RESULT external command to the external command file. I am gettinr this error in nagios3. The object needs to have the passive_checks_enabled option set to 1 for Nagios to accept passive check results over the command pipe. Nagios also offers another way to work with the statuses of hosts and services. On-demand checks are performed as part of the predictive service dependency check logic. It is called NSCA (Nagios Service Check Acceptor). Passive checks are performed by external processes and the results are given back to Nagios for processing. When everything goes smoothly, we should be able to see our new Nagios client on the Nagios website with its new service OS: unread mail for root, as well as the status green OK. Based on whether the read was successful or not, the appropriate status code, along with plugin output, is sent out. It can also be used by third-party applications running on different machines to send passive check results to a central Nagios server. The first thing that needs to be done in order to use passive checks for your Nagios setup is to make sure that you have the following options in your main Nagios configuration file: It would also be good to enable the logging of incoming passive checksthis makes determining the problem of not processing a passive check much easier. 164060 Nagios HTTP/HTTPS check via wget (with/without Proxy) Check website accessibility by return code and execution time. Nagios also supports a way to monitor hosts and services passively instead of actively. NSClient++ includes a service module that can check if a service is stopped. When you restart the Nagios, this host will start getting monitored by Nagios and the specified services will run. Even the location of the plugins directory is in there. This is a plugin for Nagios wich you can use to check if a linux service is running. In the first case, Nagios takes care of the scheduling, and the command only needs to perform the actual checks and mark the results as OK/WARNING/CRITICAL based on how a check command is configured. Nagios is the most popular tool which is used to monitor hosts and services running in your IT infrastructure. Define the checks on /etc/nagios/nrpe_local.cfg. 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! Nagios executes event handlers to handle hard states. It is generally recommended to run the Nagios service check scripts in CLI before adding them to Nagios. If the situation involves reporting problems from other applications or machines, it is definitely a use case for a passive check. . Depending on the status received on hosts and services, appropriate action is taken. Hi, thanks for your comment. This setting will expose MySQL to all available interfaces, including WAN. Enjoy unlimited access on 5500+ Hand Picked Quality Video Courses. 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. You'll see the following line inside the /etc/rc.d/init.d/nagios script for the Nagios startup: $NagiosBin -d $NagiosCfgFile $ vi /usr/local/nagios/etc/servers/devserver.cfg As a Cloudera Administrator and Kafka service owner, leading Kafka/flume/ZK services in WAP (Multi DC Environment), Leading TICK Stack (Influxdb) and Grafana along with Administration of ELK Stack (Elasticsearch, Logstash) and Cloudera Clusters with CI/CD approach, Automation. In this way, NSCA communication sent over the Internet is more secure. 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. Learn more. thanks! To check whether a specific webpage is available, use the -u option as shown below. Passive checks are useful for monitoring services that are: Examples of asynchronous services that lend themselves to being monitored passively include SNMP traps and security alerts. NPCA includes a service module that can check if a service is stopped. In addition, it is run on the Linux operating system, precisely for the purpose of monitoring devices that are executed on Windows, Unix and Linux operating systems.Its main task is to constantly check key server resources, applications, networks and tasks. Nagios, the Nagios logo, and Nagios graphics are the servicemarks, trademarks, or registered trademarks owned by Nagios Enterprises. The plugin returns a CRITICAL state if the service is not started. 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). When it comes in as a passive check, no state translation is done and Nagios stores the host and all child nodes being down. This example is going to restart the crond service as it is unlikely to cause any issues. You can create a host file inside the server directory of Nagios and mention the host and service definitions. The files and information on this site are the property of their respective owner(s). 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. The best answers are voted up and rise to the top, Not the answer you're looking for? Note: Certain nodes in the above example have combined check results, such as memory/virtual, memory/swap, and processes. 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. The script should then post results to the Nagios daemon. 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. Current status from nagios Web interface: Thank you article really help a beginer like me ;-). 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. This article assumes you have a working knowledge of Nagios. Nagios can tell what the status of the service is by reading the exit code of the check. Follow Up: struct sockaddr storage initialization by network format-string, Identify those arcade games from a 1983 Brazilian music video. Examples: CPU load, RAID status An snmp system is generally considered to have 3 components: Agents Agents expose management information on a device. On-demand service checks are also run in parallel if needed. To turn on everything you want to set debug_level=4095. It is possible to configure Nagios so that it will receive status information sent over a command pipe. Checking if a service is running using SNMP is not very straight forward, checking a process is the best solution here, please refer to the Process Checks KB article. How to install and configure nagios on centos 7 step by step ile ilikili ileri arayn ya da 22 milyondan fazla i ieriiyle dnyann en byk serbest alma pazarnda ie alm yapn. First, the servers are defined in Nagios. The application can also periodically let Nagios know if it succeeded in using the database without problems. mark separates the command from the arguments in the check_command entry. 1 check_http -p 8083 - user4556274 Jul 29, 2016 at 12:49 Add a comment 3 Answers Sorted by: 3 You can specify the port number directly in the command but you will must create one command per tested port. /usr/local/nagios/libexec/check_ping -H 192.168.1.2 -w 100.0,90% -c 200.0,60% .use: I wouldn't leave this setting on normally though, it is very verbose and fills your log file at a rapid rate. These state changes result in different state types (HARD or SOFT), which can trigger event handlers to be run and notifications to be sent out. 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. Far better then Nagios documentation. Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. If you want Nagios to treat all passive check results for hosts as if they were soft results, you need to enable the following option in the main Nagios configuration file: Passive service checks are very similar to passive host checks. I've provided some comments here, but things may not be so # clear without further explanation. After defining the command you can associate that command to a service, and then to a host. The provided scripts contain help on the syntax. 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. In many cases, the time taken is not enough, as some checks need to be performed over a longer period of time to have satisfactory results. When services change state too frequently they are considered to be "flapping". 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. 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.