I use check_http and check_tcp Nagios plugins to check some endpoints from a RHEL 8.10 box.
My problem is both return this for some domain names:
Name or service not known
Instead, well-known commands like curl, wget, ping, nc, nslookup, dig, host and getent hosts do not show any issue when solving those same host names.
I thought these Nagios plugins somehow use the wrong DNS server from /etc/resolv.conf and then I tried to export a RES_OPTIONS environment variable in order to force a DNS server, according to resolv.conf(5) manual pages, but it does not work.
Does anyone have any idea what is happening here?
