this fixes the issue where single kresd doesnt provide metrics on htt…

[adaryorg]

this one should be quite straightforward but it took me an hour to find it.
i recently started upgrading my quite unique 5.7.6 setup to 6.3 and i'm running instances with the old kresd@.service, and i noticed that after configuring the http interface only two metrics were emmited.
this fixed the issue in my environment

[vcunat]

running instances with the old kresd@.service

Running 6.x without the new manager component (knot-resolver.service normally) isn't really supported. It's not well documented (the YAML config is) and you could run into various issues.

Still, we'll try to have a look at this diff properly at some point.

[adaryorg]

Yes I know it's not supported but I have a very unique use case for it where 5.x worked perfectly, and I need 6.x for the fallback feature. I would be more than happy to chat about the implementation if you would like to hear about the use case

[vcunat]

Sure, it is interesting to read about the use case, i.e. why you need it set up this way.

[adaryorg]

In a nutshell, we provide a service where each customer (very small customer0 has a dedicated DNS server with rules to block or allow resolution of certain domains, or to have certain domains forwarded to specific resolvers, and this all works inside one physical server where each 'server' is a kresd instance with its own configuration and it serves on a dedicated port on 127.0.0.1. we have dnat rules set up to direct the traffic from customer source IP's to their dedicated kresd instance.
Internally I run as kresd@, and a snippet from configuration is:

local systemd_instance=os.getenv("SYSTEMD_INSTANCE")
if string.match(systemd_instance, '^<customer name>') then
    net.listen('127.0.0.1, <some port>, {kind = "dns"})
    net.listen('127.0.0.1, <some other port>, {kind = "webmgmt"})

    -- the rest of customer configuration like custom forwards, custom blocklist, etc ...
end

[vcunat]

Note: if forwarding differs between them in a sense which is expected to affect returned answers, you most likely don't want them sharing the cache.

[adaryorg]

oh they are not sharing the cache. i configure a small cache folder for each instance and each uses its own cache. that was one of the first things I figured out how to do