Install Check_HTTP_Content

[t3dus]

How do I go about installing check_http_content plugin on core? I have the normal nagios plugins installed but I don't know how to install the extra ones I find that I want.

I've been searching the net for over an hour and haven't found any useful tips

[mcapra]

It has no other dependencies than PERL itself and some libraries (Getopt::Std and LWP::UserAgent, latter with optional SSL support).

Running this on my vanilla Nagios Core 4 machine produces this error:

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[root@core4 tmp]# ./check_http_content
Can't locate LWP/UserAgent.pm in @INC (@INC contains: /root/perl5/lib/perl5/5.16.3/x86_64-linux-thread-multi /root/perl5/lib/perl5/5.16.3 /root/perl5/lib/perl5/x86_64-linux-thread-multi /root/perl5/lib/perl5 /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at ./check_http_content line 28.
BEGIN failed--compilation aborted at ./check_http_content line 28.

So, it appears as though my machine is missing the LWP::UserAgent Perl module. I install it via yum (you could also install it via cpan):

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yum install 'perl(LWP::UserAgent)'

And everything appears to work just fine after that:

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[root@core4 tmp]# ./check_http_content
ERROR: INVALID USAGE
        Retrieve an http/s URL and looks in its output for a given text.
        Returns CRITICAL is not found, OK if found, UNKNOWN otherwise.

        --help      shows this message
        --version   shows version information

        -U          URL to retrieve (http or https)
        -m <text>   Text to match in the output of the URL
        -t          Timeout in seconds to wait for the URL to load. If the page fails to load,
                    check_http_content will exit with UNKNOWN state (default 60)

It's worth mentioning that the check_http plugin included in nagios-plugins can also check a page's content for specific strings:
https://www.monitoring-plugins.org/doc/ ... _http.html

[rkennedy]

It has no other dependencies than PERL itself and some libraries (Getopt::Std and LWP::UserAgent, latter with optional SSL support).

Running this on my vanilla Nagios Core 4 machine produces this error:

Code: Select all

[root@core4 tmp]# ./check_http_content
Can't locate LWP/UserAgent.pm in @INC (@INC contains: /root/perl5/lib/perl5/5.16.3/x86_64-linux-thread-multi /root/perl5/lib/perl5/5.16.3 /root/perl5/lib/perl5/x86_64-linux-thread-multi /root/perl5/lib/perl5 /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at ./check_http_content line 28.
BEGIN failed--compilation aborted at ./check_http_content line 28.

So, it appears as though my machine is missing the LWP::UserAgent Perl module. I install it via yum (you could also install it via cpan):

Code: Select all

yum install 'perl(LWP::UserAgent)'

And everything appears to work just fine after that:

Code: Select all

[root@core4 tmp]# ./check_http_content
ERROR: INVALID USAGE
        Retrieve an http/s URL and looks in its output for a given text.
        Returns CRITICAL is not found, OK if found, UNKNOWN otherwise.

        --help      shows this message
        --version   shows version information

        -U          URL to retrieve (http or https)
        -m <text>   Text to match in the output of the URL
        -t          Timeout in seconds to wait for the URL to load. If the page fails to load,
                    check_http_content will exit with UNKNOWN state (default 60)

It's worth mentioning that the check_http plugin included in nagios-plugins can also check a page's content for specific strings:
https://www.monitoring-plugins.org/doc/ ... _http.html

This kilt it. @mcapra is right, why not just use the string or regex matching with check_http?

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 -r, --regex, --ereg=STRING
    Search page for regex STRING

[tmcdonald]

As a general answer to the "How do I install this?" question, you will need to place the plugin in the same directory as the rest, make sure it is executable by the nagios user, and then create a command for it: https://assets.nagios.com/downloads/nag ... ml#command

[t3dus]

I'm running Nagios 4.1.1 on a Raspberry PI using Raspberian as the OS.

I'm pretty new to linux and don't quite understand the check_http string that you pointed out above.

What would the host command look like in the .cfg file?

[t3dus]

For example if I try this..

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define service{
        use                             generic-service         ; Name of service template to use
        host_name                       snapgeek.com
        service_description             HTTP
        check_command                   check_http -H snapgeek.com -u https://snapgeek.com/meet-matt/
        notifications_enabled           1
        }

I get this error code

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Checking objects...
Error: Service check command 'check_http -H snapgeek.com -u https://snapgeek.com/meet-matt/' specified in service 'HTTP' for host 'snapgeek.com' not defined anywhere!
        Checked 51 services.
        Checked 27 hosts.
        Checked 2 host groups.
        Checked 0 service groups.
        Checked 2 contacts.
        Checked 1 contact groups.
        Checked 25 commands.
        Checked 5 time periods.
        Checked 0 host escalations.
        Checked 0 service escalations.
Checking for circular paths...
        Checked 27 hosts
        Checked 0 service dependencies
        Checked 15 host dependencies
        Checked 5 timeperiods
Checking global event handlers...
Checking obsessive compulsive processor commands...
Checking misc settings...

Total Warnings: 0
Total Errors:   1

***> One or more problems was encountered while running the pre-flight check...

     Check your configuration file(s) to ensure that they contain valid
     directives and data defintions.  If you are upgrading from a previous
     version of Nagios, you should be aware that some variables/definitions
     may have been removed or modified in this version.  Make sure to read
     the HTML documentation regarding the config files, as well as the
     'Whats New' section to find out what has changed.

[dwhitfield]

You need to define the command separately.

For example:

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define command {
    command_name   WhateverYouWantButNeedToUseThisWhenYouCallIt
    command_line    check_http -H snapgeek.com -u https://snapgeek.com/meet-matt/
}

So, your service looks like

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define service{
        use                             generic-service         ; Name of service template to use
        host_name                  snapgeek.com
        service_description      HTTP
        check_command          WhateverYouWantButNeedToUseThisWhenYouCallIt
        notifications_enabled   1
        }

This is not a particular good example, because it isn't reusable, but it should get you going until you get a chance to look over https://assets.nagios.com/downloads/nag ... tions.html

The above assumes you actually have a host named snapgeek.com. Each service must be attached to a host, but a host need not have a service (since there is a separate host check).

[t3dus]

You need to define the command separately.

For example:

Code: Select all

define command {
    command_name   WhateverYouWantButNeedToUseThisWhenYouCallIt
    command_line    check_http -H snapgeek.com -u https://snapgeek.com/meet-matt/
}

So, your service looks like

Code: Select all

define service{
        use                             generic-service         ; Name of service template to use
        host_name                  snapgeek.com
        service_description      HTTP
        check_command          WhateverYouWantButNeedToUseThisWhenYouCallIt
        notifications_enabled   1
        }

This is not a particular good example, because it isn't reusable, but it should get you going until you get a chance to look over https://assets.nagios.com/downloads/nag ... tions.html

The above assumes you actually have a host named snapgeek.com. Each service must be attached to a host, but a host need not have a service (since there is a separate host check).

That works but lets say I want several websites to do the same check but with different urls. Do I have to define the command for each website differently in command.cfg or can i do it with arguments some other way?

FYI, I'm looking through that link you sent too to try to get a better understanding.

[dwhitfield]

This is just a guess, but since you are running 4.3.1, you probably compiled from source. Is that correct? If that is correct, you should have the following file on your system: https://github.com/NagiosEnterprises/na ... nds.cfg.in

If you don't have that file, you could obviously look at the file on github to see various examples.

Below is a sample from that file. You'll see it really depends on the command how many ARGs it takes.

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# 'check_local_procs' command definition
define command{
        command_name    check_local_procs
        command_line    $USER1$/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$
        }


# 'check_local_users' command definition
define command{
        command_name    check_local_users
        command_line    $USER1$/check_users -w $ARG1$ -c $ARG2$
        }


# 'check_local_swap' command definition
define command{
	command_name	check_local_swap
	command_line	$USER1$/check_swap -w $ARG1$ -c $ARG2$
	}


# 'check_local_mrtgtraf' command definition
define command{
	command_name	check_local_mrtgtraf
	command_line	$USER1$/check_mrtgtraf -F $ARG1$ -a $ARG2$ -w $ARG3$ -c $ARG4$ -e $ARG5$
}

[t3dus]

I'm running Nagios 4.1.1 which I haven't updated to 4.3 but I did compile it from source. I haven't bothered to try to update to 4.3 because I haven't had a huge desire to break what I currently worked so hard to get working which is more or less how i want it minus the ability to use keywords on website checks.