nagios service check example nagios service check example

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. I wouldn't leave this setting on normally though, it is very verbose and fills your log file at a rapid rate. This task is really easy as Nagios has a built-in command for this. host_name Server01 Do not wait for whole document body to download. Agree Default is 10 seconds. Securely download your document with other editable templates, any time, with PDFfiller. Let us see an example to perform checks on host . rev2023.3.3.43278. External applications can submit passive host check results to Nagios by writing a PROCESS_HOST_CHECK_RESULT external command to the external command file. Go to the /usr/local/nagios/libexec dir (assuming you have installed nagios from source, if you have used a package from your distribution, check the docs of your package): $ cd /usr/local/nagios/libexec execute the check_dns plugin with the --help switch. 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. Nagios allows applications and event handlers to send out passive check results for host objects. Check HTTPS Check whether Apache HTTPS is running on a remote server using check_http. Host is just like a computer; it can be a physical device or virtual. The default FQDN used for testing is www.google.com, but it can be changed as needed. How to Install Nagios? This command accepts the host name, service description, status code, and the textual output from a check. 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. 164060 Nagios HTTP/HTTPS check via wget (with/without Proxy) Check website accessibility by return code and execution time. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. This feature is only available to subscribers. 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 example is going to restart the crond service as it is unlikely to cause any issues. All other servicemarks and trademarks are the property of their respective owner. 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 Nagios can be used to monitor Apache web server as well. Copyright (c) 1999-2014 Nagios Plugin Development Team <devel@nagios-plugins.org> This plugin tests the HTTP service on the specified host. 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. just because i had already looked in the commands.cfg file to figure out which commands were running, but i wanted to know what flags were being set. More information on the flap detection logic can be found here. This requires trying to read the entire disk directly from the block device (such as /dev/sda1) and checking if the attempt has failed. 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. 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. @sunardo I just ran into this exact same thing. Then we are removing spaces using sed and finally cut the appropriate field using cut, i this case field 5 is what we want. Is there a more efficient way to do this? . They may or may not work on: 44 # your system, as they must be modified for your plugins. Does a summoned creature play immediately after being summoned by a ready action? An external application checks the status on hosts/services and writes the result to External Command File. Try to put full path in the command line. vegan) just to try it, does this inconvenience the caterers and staff? Thanks for contributing an answer to Server Fault! 28. Nagios executes event handlers to handle hard states. Nagios will ignore all check results for hosts that had not been configured before it was last (re)started. We can also do it at a contact level, by disabling notifications . You have entered an incorrect email address! These are examples of the graphs that can be created and embedded using the graph generator in the Graphs tab. And in Puppet agent, I have to define the environment (Dev, Test or Prod). When it comes in as a passive check, no state translation is done and Nagios stores the host and all child nodes being down. 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. The following line is commented out to make MySQL listens on all interfaces. 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. The plugins can be in any language, Nagios only cares They can be the following: 0: OK use generic-service ; Name of service template to use check_command check_http -H MYIP -u http://MYIP/test.php The object needs to have the passive_checks_enabled option set to 1 for Nagios to accept passive check results over the command pipe. Thus, the difference between active and passive check is that active checks are run by Nagios and passive checks are run by external applications. 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. Would you please be so kind as to help me? After installing nagios and nagios-plugins-all (via yum), I've c. The object file localhost.cfg allows for parameters to be passed to check_ssh. We make use of First and third party cookies to improve our user experience. 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. This is because, very often, passive checks are used to report host and service statuses from other Nagios instances. 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. Or you can create a custom variable to store the port number , with your example: 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% can anyone help me out for this problem:-, Check-Website-Response If up-to-date information has been provided by a passive check during this period, then it will not perform active checks. 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. How to handle a hobby that makes income in US. hello.. In other cases, passive checks are the way to go. Otherwise we must rely on parsing the # output from the service management tool. When a host is reported to be DOWN as a passive check result, Nagios does not perform a translation from DOWN to UNREACHABLE. The module can only check if the service is started, you could however use the negate plugin to invert the returned result from the plugin (hence making CRITICAL an OK state). 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. 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. How can I get it to work with https with Nagios4 and plugins 2.x? I am running into the same problem as David Nagios can detect when services start flapping, and can suppress notifications until flapping stops and the service's state stabilizes. 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. In such cases, only reports regarding hard state changes are propagated across Nagios servers. The next time Nagios reads the external command file it will place the results of all passive checks into a queue for later processing. A good example would be a server that is a part of an application, processing job queues using a database. Some methods support checking multiple services at once. This allows for seamless integration of status information from external applications with Nagios. The following screenshot shows a complete overview of all the service checks that have been configured so far. Is there a proper earth ground point in this switch box? To identify the status of a monitored service, Nagios runs a check plugin on it. How to tell which packages are held back due to phased updates. With a little tweaking, Nagios can help monitor this application port as well. The NSCA addon consists of a daemon that runs on the Nagios hosts and a client that is executed from remote hosts. More information on how this works can be found here. The best answers are voted up and rise to the top, Not the answer you're looking for? This can be done to gather all critical errors to a single, central place. Nagios dependencies.cfg example file. Nagios stores the status of the hosts and services it is monitoring to determine if they are working properly or not. 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. Nagios server in this example is hosted on 192.168.0.150 and an example client is hosted on IP 192.168.0.200. 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. Nagios can tell what the status of the service is by reading the exit code of the check. Nagios comes with a wide range of built-in scripts for monitoring services. It's pretty simple. 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). By default Nagios supports URL monitoring and there is an command check_http, however if you want to monitor URL like SSL certification you can also do by extending the command options. For example sudo gedit /usr/local/nagios/etc/servers/ubuntu_host.cfg # Ubuntu Host configuration file On-demand as needed for predictive service dependency checks. Expected response string. The script should then post results to the Nagios daemon. Default is 80, This will use HTTPS using default 443 port. These are executed on regular intervals, as defined by check_interval and retry_interval. There are many more services in Nagios which can be used to monitor pretty much anything on the running host. It can be used to send results from one Nagios instance to another. 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. Consider that you have put your host definitions inside host1.cfg file in /usr/local/nagios/etc/objects directory. In cases where the checks require the deployment of long-running processes or monitoring information constantly, this should be done as a passive service. Nagios Plugins Nagios Plugins does not include a service plugin however the linux-nrpe-agent does provide check_init_service. Filters such as firewall and TCP wrappers should be used. 1. When Nagios plans and receives results from active checks, it takes the actual network topology into consideration and performs a translation of the states based on this. In most cases you'll use Nagios to monitor your hosts and services using regularly scheduled active checks. Nagios will ignore all check results for services that had not been configured before it was last (re)started. NPCA includes a service module that can check if a service is stopped. if one of my checked systems goes down, and therefore fails a PING check, I do NOT need to be notified that a file system is unavailable, or that SSH is down, too. 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). 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. The Nagios plugin can be remotely executed on other Linux/Unix machines using NRPE. 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. 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. The host or the services will be tested again and again till the time the status is permanent. 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. ##### ##### # # SAMPLE SERVICE CHECK COMMANDS # # These are some example . Nagios also offers a tool for sending passive check results for hosts and services over a network. Here is how it can be done. By default, Nagios handles results from active and passive checks differently. Is it possible to check a web page through an authenticated proxy server? The first parameter tells Nagios that it should check whether the results from the checks are up-to-date. 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.