CNAME Support?

[SlothCroissant]

Hey there, loving Blocky so far! I've got a quick question that I'm hoping is just due to me missing something simple: Does blocky support manual CNAMEs to internal hosts?

Use case: I host a webserver on webserver.lan. This web server hosts several sites externally to the public internet - let's say app1.web.url, app2.web.url, app3.web.url. With my current PiHole setup, I use the underlying dnsmasq config options for CNAME mapping:

--cname=<cname>,[<cname>,]<target>[,<TTL>]
Return a CNAME record which indicates that <cname> is really <target>. There is a significant limitation on the target; it must be a DNS record which is known to dnsmasq and NOT a DNS record which comes from an upstream server. The cname must be unique, but it is permissible to have more than one cname pointing to the same target. Indeed it's possible to declare multiple cnames to a target in a single line, like so: --cname=cname1,cname2,target
If the time-to-live is given, it overrides the default, which is zero or the value of --local-ttl. The value is a positive integer and gives the time-to-live in seconds.

Ask

Does blocky support manual CNAMEs to internal hosts?

What I've tried

First off, I tried just using the customDNS.mapping YAML configuration (doc ref) to try to add webserver.lan as the target for my FQDNS as so:

customDNS:
  mapping:
    webserver.lan: 10.1.0.10
    app1.url.com: webserver.lan
    app2.url.com: webserver.lan
    app3.url.com: webserver.lan

This config throws an error on startup which makes sense: FATAL wrong file structure: invalid IP address 'webserver.lan'

---

Next, I tried conditional.rewrite YAML configuration (doc ref) to remap my app*.url.com URLs to webserver.lan as so:

customDNS:
  mapping:
    webserver.lan: 10.1.0.10
conditional:
  rewrite:
    app1.url.com: webserver.lan
    app2.url.com: webserver.lan
    app3.url.com: webserver.lan

This config loads, but when I query app1.url.com, it tosses it upstream and fails (as I assume it rewrites it to webserver.lan and fails Cloudflare's resolver):

INFO queryLog: query resolved answer= client_ip=10.1.10.100 client_names=10.1.10.100 duration_ms=99 question=A (app1.url.com.) response_code=NXDOMAIN response_reason=RESOLVED (https://1.0.0.1:443/dns-query)

Any guidance you could provide? Or is this not currently possible at this point? Thanks!

[kwitsch]

Had a similar problem a while back and figured that a conditional block without a mapping (rewrite only) is ignored somehow.
Try adding a mapping "lan: 127.0.0.1" to your conditional block.
This way blocky queries itself for all hosts in the lan domain and your custom mapping should work correctly.

[0xERR0R]

CustomDNS creates only A and AAAA entries -> you can only map a custom url (with all subdomains) to the particular IP address.

Conditional mapping redirects some queries to the defined DNS resolver.

I think in your use case you can try to define customDNS mapping either for each app url like:

customDNS:
  mapping:
    app1.url.com: 10.1.0.10
    app2.url.com: 10.1.0.10
    app3.url.com: 10.1.0.10

or for the whole domain (in this case for all subdomains: *.url.com):

customDNS:
  mapping:
    url.com: 10.1.0.10

[0xERR0R]

I created an issue to track it: #465

[Serverfrog]

in kinda the same area, its about Issue #467 : as far as i noticed (could be wrong) it isn't in v0.18. so is there an ETA for 0.19 or v0.18.1 due to the fact that will currently block me to generate SSL Certificates with cert-manager with DNS0 challange ;)

[0xERR0R]

#467 was fixed for 0.19 (next release) -> can be tested with docker "development" tag. #465 is unscheduled yet

[Serverfrog]

yhea im currently on the way to switch to development, but is there an ETA for the 0.19? in sense of, its not stable enough currently or feature missing? not to pressure things, just for the information ;) (i mean i could now use the development tag and report back if things dont work well)

[0xERR0R]

There is no ETA, I'm trying to release every 2-3 month. All implemented issues on development "should" be in order stable enough 😄, since I use this version on my home environment 🤦
There is also no "code freeze" and deep testing phase before each release.
The last release was in february, I think we can release 0.19 this month.

[Serverfrog]

nice ;) i mean if it works i dont see a reason for to switch away to a "stable" version :P Main thing for me is to get cert-manger working again after i switched from pihole to blocky