The next parameter specifies the number of seconds after which Nagios should consider the results to be out of date. The scripts stored in /etc/nagios-plugins/config/ can shed some light on the awesome capabilities of Nagios. The next time Nagios reads the external command file it will place the results of all passive checks into a queue for later processing. An external application checks the status on hosts/services and writes the result to External Command File. More information on cached checks can be found here. This allows for seamless integration of status information from external applications with Nagios. /usr/nagios/libexec/check_http .. Base your decision on 2 verified in-depth peer reviews and ratings, pros & cons, pricing, support and more. It can test normal (http) and secure (https) servers, follow redirects, search for strings and regular expressions, check connection times, and report on 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. . Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? 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. Nagios, NagiosXI, Nagios Core, Nagios Logger, Manage Engine, Idera, Quest, Thousand Eyes Idera Suite and Quest, SQL Monitoring Solution Implementation I've # provided some comments here, but things may not be so clear without further # explanation, so make sure to read the HTML documentation! Also, MySQL would not let just any host to connect to it. A command to submit passive checks is PROCESS_SERVICE_CHECK_RESULT (visit http://www.nagios.org/developerinfo/externalcommands/commandinfo.php?command_id=114). 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. Passive checks are performed by external processes and the results are given back to Nagios for processing. In this tutorial, the following three servers are being used. Nagios: Disable notifications from command line on Windows/Linux. In case you don't have the plugin in the Nagios server, you can install it with: So, summarizing, the NRPE will run a script in a remote host, and return the exit code to the Nagios server. Nagios Core is an Open Source system for monitoring hosts, networks and services. this is more along the lines of what i meant. It allows the implementation of plugins, developed by the community, or even allows us to configure our own monitoring scripts. How to install and configure Nagios Core. Note: Passive host checks are normally treated as HARD states, unless the passive_host_checks_are_soft option is enabled. Examples: CPU load, RAID status An snmp system is generally considered to have 3 components: Agents Agents expose management information on a device. Default is HTTP/1. debug_level=2048 With nagios in debug mode I simply tail the debug_log file debug_file=/var/log/nagios3/nagios.debug. Use Puppet environments. Do not wait for whole document body to download. Passive Checks and NSCA (Nagios Service Check Acceptor), Technology news, insights and tutorials from Packt, Top 6 Cybersecurity Books from Packt to Accelerate Your Career, Your Quick Introduction to Extended Events in Analysis Services from Blog, Logging the history of my past SQL Saturday presentations from Blog, Storage savings with Table Compression from Blog Posts SQLServerCentral, Daily Coping 31 Dec 2020 from Blog Posts SQLServerCentral, Learning Essential Linux Commands for Navigating the Shell Effectively, Exploring the Strategy Behavioral Design Pattern in Node.js, How to integrate a Medium editor in Angular 8, Implementing memory management with Golangs garbage collector, How to create sales analysis app in Qlik Sense using DAR, http://www.nagios.org/developerinfo/externalcommands/commandinfo.php?command_id=114, ExploringForms in Angular types, benefits and differences. It can also send reports after a database recovery, or periodically, even if connectivity to the database has been consistently available, so that Nagios has an up-to-date status. So in this blog post is all about how I used Hiera to manage the Dev,Test, Prod Stratos environments. It essentially does the same thing as a debug level of 2048, but can be used on a per-plugin basis. Nagios will ignore all check results for hosts that had not been configured before it was last (re)started. 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. NPCA includes a service module that can check if a service is running. 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. Try to put full path in the command line. You never know how many (if any) traps or alerts you'll receive in a given time frame, so it's not feasible to just monitor their status every few minutes. great! To check whether a specific webpage is available, use the -u option as shown below. How can we prove that the supernatural or paranormal doesn't exist? Nagios can tell what the status of the service is by reading the exit code of the check. You can check whether a SSL certificate of the website expires within the next X number of days as shown below. Passive service checks are often used to report the results of long lasting tests asynchronously. TRUST_EXIT_CODE=0 usage () { cat <<EOF These types of checks are called Active Checks. This can be done in addition to active checks, to identify critical problems earlier. sudo usermod -aG docker kifarunix. Yeah, it's totally brute-force, but it works for me. This feature is only available to subscribers. Checking a service using SNMP is not very straight forward, checking a process is the best solution here, please refer to the Process Checks KB article. Nagios.cfg is the main configuration file for your Nagios Core. Check whether Apache HTTPS is running on a remote server using check_http. 2. Related Commands. 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 The first parameter tells Nagios that it should check whether the results from the checks are up-to-date. Force a check and you will see exactly how the command is being run. It is called NSCA (Nagios Service Check Acceptor). How can I manually run a nagios check from the command line? However, in a big environment it is very likely to need some custom checks for specific uses, for instance: Checking on a certain task result, monitoring an in-house developed application, among others. Nagios can be used to monitor Apache web server as well. Nagios also supports a way to monitor hosts and services passively instead of actively. There are no attachments for this article. If you are new to the Nagios network monitoring system, see the resources at the Nagios website. More information on how this works can be found here. This is a plugin for Nagios wich you can use to check if a linux service is running. ##### ##### # # SAMPLE SERVICE CHECK COMMANDS # # These are some example . It can also be used by third-party applications running on different machines to send passive check results to a central Nagios server. Nagios executes event handlers to handle hard states. To learn more, see our tips on writing great answers. Nagios can tell what the status of the service is by reading the exit code of the check. Learn more about Stack Overflow the company, and our products. I've provided some comments here, but things may not be so # clear without further explanation. $ vi /usr/local/nagios/etc/servers/devserver.cfg # Sample object config file for Nagios : 3 # 4 # Read the documentation for more information on this configuration file. An example shell script of how to submit passive service check results to Nagios can be found in the documentation on volatile services. A user [emailprotected] is created in MySQL server. The following file can be modified to do the job. 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. Even the location of the plugins directory is in there. The line should look like: Define the standard checks that you will perform on every client with NRPE. On the client host that you want to use to connect to remote Docker daemon, generate SSH keys from your user account; ssh-keygen. The flexibility provided by Nagios is perfect for these case scenarios. Nagios also offers a way of combining the benefits of both active and passive checks. First, install the Nagios Core server. Active checks reach out from the Nagios host and test if a service is doing what it's expected to do. Nagios check service frequency based on service status, how can execute nagios commands from command line in linux. (1 + 2 + + 2048), Also note that your debug file will grow quickly and then rotate itself. Thus, the difference between active and passive check is that active checks are run by Nagios and passive checks are run by external applications. In the left navigation pane, select "Process Info" and then "Disable Notifications" and "Commit.". We must install this software there to install the "check_nrpe" plugin that we use to perform active checks using the NRPE. host_name Server01 On-demand checks are performed as part of the predictive service dependency check logic. The NSCA addon consists of a daemon that runs on the Nagios hosts and a client that is executed from remote hosts. 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. Method 2. check_command /usr/share/nagios/plugins/check_http -H MYIP -u http://MYIP/test.php, Hi, 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. It can be used to send results from one Nagios instance to another. 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. By using this website, you agree with our Cookies Policy. So the Nagios Core version is 3.5.1. 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. Nagios can monitor different mail server components like SMTP, POP, IMAP and mailq. Each of these options opens the Manage Service Template screen.The New option will have no pre-selected directive values, Copy lets you create a new template based on an existing templates properties, and Modify enables the editing of an . Hi, thanks for your comment. Another example is where an application already processes information such as network bandwidth utilization. If youve installed Nagios from source, check_httpd command will be located in the /usr/local/nagios/libexec directory. Enjoy unlimited access on 5500+ Hand Picked Quality Video Courses. Up To: Contents Check WMI Plus allows you to check multiple services, here is an example that checks for two services that are running. Affordable solution to train a team and make them project ready. What is check_http? For example, you can use the 'check_http' plugin to verify that a web server is running, is returning the right text, or has an up-to-date SSL certificate. check_command check_http -H MYIP -u http://MYIP/test.php This tutorial was tested using Nagios Core 4.3.4 on Debian 9.2if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-box-3','ezslot_3',106,'0','0'])};__ez_fad_position('div-gpt-ad-howtoforge_com-box-3-0'); Even though Nagios Exchange has thousands of available plugins to freely download, sometimes the status needed to be checked is very specific for your scenario. Now that the syntax is available, TCP port 80 can be checked as follows. 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. 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. When Nagios daemon reads external command file, it reads and sends all the passive checks in the queue to process them later. 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. Does a summoned creature play immediately after being summoned by a ready action? This command accepts the host name, status code, and the textual output from a check. 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). You need to add the full path to it in the check_command. 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. In most cases you'll use Nagios to monitor your hosts and services using regularly scheduled active checks. 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. Nagios check_udp_ports returning critical: result to scheduled check, runs fine manually, Nagios - check procs and --metric=elapsed on the same service. Nagios also offers another way to work with the statuses of hosts and services. The performance of on-demand service checks can be significantly improved by implementing the use of cached checks, which allow Nagios to forgo executing a service check if it determines a relatively recent check result will do instead. The object file localhost.cfg allows for parameters to be passed to check_ssh. 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. NSClient++ includes a service module that can check if a service is stopped. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? Nagios' check_ssh (of course) keeps marking the process as critical since it can't connect on that port. The host status code should be 0 for an UP state, 1 for DOWN and 2 for an UNREACHABLE state. Hello, ask a question, check_http detect page size, page size detection value changes again, the alarm. The sections below provide examples of how to perform these checks using different methods. Let's consider I have the Nagios server configured to alert only on critical status, so I want an alert if I have too many services on a Warning status. 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. Enable and restart the nrpe service: [user@mon]# systemctl enable nrpe [user@mon]# systemctl restart nrpe. Last updated on September 22, 2020 by Sarmed Rahman. Nagios: Simple Oracle Check. 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. 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. Let us assume that the following custom application is also running in the network, listening on a particular port. vegan) just to try it, does this inconvenience the caterers and staff? Hosts and service configurations are the building blocks of Nagios Core. ##### # # NAGIOS.CFG - Sample Main Config File for Nagios # # Read the documentation for more information on this configuration # file. 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. Expected response string. When it comes in as a passive check, no state translation is done and Nagios stores the host and all child nodes being down. Add the file to the standard Nagios Core location, /usr/local/nagios/libexec. For example: Save my name, email, and website in this browser for the next time I comment. The Nagios server is running on Ubuntu. This user is then granted all permission to all databases and will be used for monitoring. 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. We make use of First and third party cookies to improve our user experience. In order to allow remote hosts to send passive check results to the monitoring host, I've developed the NSCA addon. This will give an idea on whether the execution will be successful and what the output of the script will look like. Nagios check_by_ssh returns status 3 even though running the command manually works? To allow it to grow bigger before rotating, add more zeroes, for example. 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. If the situation involves reporting problems from other applications or machines, it is definitely a use case for a passive check. The following diagram shows how both active and passive checks are performed by Nagios. These are real-time graphs showing things like CPU usage, memory usage, and bandwidth. The host or the services will be tested again and again till the time the status is permanent. In this tutorial, we'll install Nagios on an Ubuntu 19.10 server, but these steps should work on any Debian-based distro. First you should define a command in the commands.cfg file. To monitor hosts and services running on remote machines, Nagios executes plugins and tells what information to collect. To identify the status of a monitored service, Nagios runs a check plugin on it. Some methods support checking multiple services at once. I am running into the same problem as David 1. For example, when a web application cannot connect to the database, it will let Nagios know about it immediately. Unlike active checks, Nagios will not take network topology into consideration by default. use generic-service ; Name of service template to use 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. I wrote a plugin in a bash script to check for current Warnings. Xmodulo 2021 About Write for Us Feed Powered by DigitalOcean, Creative Commons Attribution-ShareAlike 3.0 Unported License, Monitor whether MySQL is running by checking port, Monitor the availability of certain database. Note that all the configuration in this section is done on the client to be checked, not in the nagios server. Always remember, prior to reloading Nagios, check that there are no errors in the configuration. This example is going to restart the crond service as it is unlikely to cause any issues. Architect and design WAP data flow using BigData Platform. 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). Can i specify what a valid response is, i.e. To figure this out I set nagios into debug mode with the configuration like this. This defines that check_nrpe is the command and check_root_home_du is the value of $ARG1$. Service or Daemon checks are system processes that run in the background, usually configured to start when the system boots. JOB, /usr/lib/nagios/plugins/check_nrpe -H 3.6.123.156 -c check_root_home_du. It can report each problem when accessing the database. 5 check_http examples Consider that you have put your host definitions inside host1.cfg file in /usr/local/nagios/etc/objects directory. Nagios will ignore all check results for services that had not been configured before it was last (re)started. this is THE MOST comprehensive and straight forward turorial I've seen. 5 check_http Command Examples 1. 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). 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. Connect and share knowledge within a single location that is structured and easy to search. check_http: command not found. :), I will also menton for new users that using, The debug_levels are binary - 2048 only turns on messages from macros. In such cases, Nagios decides when a check is to be performed, runs the check and stores the result. NSCA stands for Nagios Service Check Acceptor. (1)Nagios. Contribute to vishalsingh17/GitiPedia development by creating an account on GitHub. That is superb artile I was looking for! For example, a plugin which returns a WARNING state will cause a service to have a WARNING state. Far better then Nagios documentation. There are many more services in Nagios which can be used to monitor pretty much anything on the running host. Check WMI Plus includes a service module that can check if a service is stopped. If I used the first method, I have to keep separate site.pp for each environment. When defining and testing new services in nagios I have been restarting nagios, then clicking the service, and rescheduling a check for as soon as possible, then waiting until the check happens. I will use a simple example. Nagios comes with a wide range of built-in scripts for monitoring services. . Is it possible to check a web page through an authenticated proxy server? Check HTTPS Check whether Apache HTTPS is running on a remote server using check_http. you have the flexibility of sending the passive check to Nagios with a different hostname. Nagios will be configured to monitor SMTP and mail queue of the server. What you are doing down is sending a Passive check result for the service SNMP Traps - Users for the host CentOS. Does ZnSO4 + H2 at high pressure reverses to Zn + H2SO4? 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. 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. This is a plugin for Nagios wich you can use to check if a linux service is running. Nagios Enterprises makes no claims or warranties as to the fitness of any file or information on this website, for any purpose whatsoever. When a passive result check comes in to Nagios, Nagios expects that the result already has a network topology included. When max_check_attempts is executed and status of the host or service is still not OK, then hard state is used. For any support related questions please visit the Nagios Support Forums at: Article Number: 775 | Rating: Unrated | Last Updated by. Submitting passive host check results to Nagios requires sending a command to the Nagios external command pipe. 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. NRDP has several benefits over NSCA, including: It is vital to make sure only legitimate networks have access to the 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. Now we know that the custom plugin is working on the client and on the server, and that the NRPE is communicating correctly, we can go ahead and configure Nagios files for checking the remote device. External applications can submit passive host check results to Nagios by writing a PROCESS_HOST_CHECK_RESULT external command to the external command file. The example contains partial output. A good example would be a server that is a part of an application, processing job queues using a database. Host is just like a computer; it can be a physical device or virtual. Here is the output when the RemoteAccess service was started: Checking if a service is stopped using SNMP is not very straight forward, checking a process is the best solution here, please refer to the Process Checks KB article. November 2012, by Simon Krenger. For example sudo gedit /usr/local/nagios/etc/servers/ubuntu_host.cfg # Ubuntu Host configuration file notifications_enabled 0 The Nagios plugin can be remotely executed on other Linux/Unix machines using NRPE. Be aware that the service module is cAsE SeNsative, you can overcome this with the match= argument. Making statements based on opinion; back them up with references or personal experience. 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. Learn more. This is how your host definitions look currently . Once again, we are dealing with open source software, and Nagios purpose is aimed at monitoring computer systems. The same queue that is used for storing results from active checks is also used to store the results from passive checks. The external application writes the results of the check to the. 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. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Monthly digest of what's new and exciting from us. The script should then post results to the Nagios daemon. How to handle a hobby that makes income in US. This should enable MySQL to listen on all interfaces, as well as accept incoming connections from user nagios at any host. When it is an active check result, Nagios takes the fact that switch1 is down into account and maps the child nodes result into an UNREACHABLE state. When services change state too frequently they are considered to be "flapping". Nagios server in this example is hosted on 192.168.0.150 and an example client is hosted on IP 192.168.0.200. Affordable solution to train a team and make them project ready. Nonetheless, they can be tuned to match the requirements. This way, Nagios can help monitor the accessibility of both MySQL servers and the database stored within the servers. Pass the specified string as User Agent in HTTP header. -c 7 -w 5 -v. Any pointer if I am missing anything but obvious. Just cd (or not) into the plugins directory (this directory location varies, depending on how you've installed it, but check /usr/local/nagios, or /usr/lib/nagios). 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. You'll see the following line inside the /etc/rc.d/init.d/nagios script for the Nagios startup: $NagiosBin -d $NagiosCfgFile How to use it? These checks help ensure that the dependency logic is as accurate as possible. In an earlier post, I showed how to . An external application checks the status of a host or service. Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. The files and information on this site are the property of their respective owner(s). The default FQDN used for testing is www.google.com, but it can be changed as needed.