Procedure: isc dhcp configuration check

[lzap]

Manual edits in ISC DHCP often lead to "Cannot add Subnet" error or other parsing issues as our parser is very limited. This procedure (should not be really check but a "command" you can run when needed) would do this (tested on Satellite 6.1+):

#!/bin/bash
curl -ks --cert /etc/foreman/client_cert.pem --key /etc/foreman/client_key.pem --cacert /etc/foreman/proxy_ca.pem https://$(hostname):9090/dhcp
dhcpd -t -cf /etc/dhcp/dhcpd.conf

The first command returns JSON of subnet data, error message otherwise. The second is syntax check of ISC, returns some text (always), we need check the return value instead.

[lzap]

More info at: https://access.redhat.com/solutions/2988341

We can implement the same for DNS.

Also note that certificate paths are different on Server and Katello-Proxy (Capsule), take that into account. When implementing this check, we should not use CURL but directly require parsing API from smart-proxy in order to catch exceptions.

[iNecas]

I'm not sure requiring the parser code from proxy is such a good idea: this can get messy pretty quickly

[lzap]

Then just a curl test and testing if that's HTTP 200 is fine, but it will not catch missing subnets. Alternatively there could be external script in smart-proxy with proper unit tests that could be called instead of requiring, that would be cleanest.

Note, I see that certificates are hardcoded in your patch, but the paths are different on Satellite Server and Capsule! I hope maintain will work on Capsule too.