Recently, we have a strange situation that certain critical users cannot log into an FTP server. Of course, Icinga is helping me to check this going forward:
First, define a service check:
define service{
use bidaily-service
host_name ftp.example.com
service_description FTP Login ftp.example.com-scott
check_command check_ncftpls!'ftp://scott:tiger@ftp.example.com/'
notifications_enabled 0
}
Next, catch that odd case when the script itself is missing (in past, payload of Nagios packages has added/dropped parts that I need)
define servicedependency{
dependent_host_name ftp.example.com
dependent_service_description FTP Login ftp.example.com-scott
host_name localhost
service_description Runnable check_ncftpls
execution_failure_criteria w,c,u
notification_failure_criteria w,c,u
}
Finally, the script itself:
#!/bin/bash
NCFTPLS=$(which ncftpls) ||{ echo "FAIL ncftpls not found"; exit 2; }
test -x ${NCFTPLS} || { echo "FAIL ${NCFTPLS} runnable|"; exit 2; }
${NCFTPLS} $@ &OK"; exit 0; }
echo "${NCFTPLS} failed"
exit 2
Now, I could’ve/should’ve used the hostname in the check itself, but I was more interested in just getting it there. I will probably clean it up someday, make it more reusable, but there it is.
Note that I did not establish a dependency on the ncftpls -bearing package itself in my RPM hierarchy simply because it’s perfectly fine for the “runnable” to fail, and the script itself will never thereafter hit the FTP server until the script it safely runnable. Sure, it’s listed as a failure, but it’s a choice against a huge dependency that typically brings in 100 packages of inconsistent perl and such (hey, “just hit cpan”, they’ll do that in datacenters, sure)