Consider documenting the "FQDN/search-domain flows" for container-to-container networking on a custom network?

[l-hedgehog]

Both the recently refactored networking docs and the more recently added skills states that "container-to-container networking"

... does not ... work for ... container(s) ... on a custom network ... that gap is tracked ... as #1809

This seems too strong a claim given in #1809 it was mentioned:

... configuring a DNS domain with container system dns create <domain> plus setting dns.domain ... can make FQDN/search-domain flows work ...

I believe the "FQDN/search-domain flows" here would be sth. like this:

% container network create foo                                                                             
foo
% container run --rm -d --dns-search=foo.test --dns-search=test --name http-server.foo.test --network foo python:alpine python3 -m http.server
http-server.foo.test
% container run -it --rm --dns-search=foo.test --dns-search=test --network foo alpine/curl curl -v http://http-server.foo.test:8000
* ...
* Host http-server.foo.test:8000 was resolved.
* IPv6: ...
* IPv4: 192.168.65.2
*   Trying 192.168.65.2:8000...
* Established connection to http-server.foo.test (192.168.65.2 port 8000) from 192.168.65.3 port 39362 
* using HTTP/1.x
> GET / HTTP/1.1
> Host: http-server.foo.test:8000
> User-Agent: curl/8.21.0
> Accept: */*
> 
* Request completely sent off
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Server: SimpleHTTP/0.6 Python/3.13.15
< Date: Fri, 04 Sep 2026 10:32:58 GMT
< Content-type: text/html; charset=utf-8
< Content-Length: 809
< 
...
* shutting down connection #0

In fact, even the "looking up another container by its bare hostname" works, to some extent:

% container run -it --rm --dns-search=foo.test --dns-search=test --network foo alpine/curl curl -v http://http-server:8000
* Host http-server:8000 was resolved.
* IPv6: ...
* IPv4: 192.168.65.2
* ...
*   Trying 192.168.65.2:8000...
* Established connection to http-server (192.168.65.2 port 8000) from 192.168.65.4 port 54438 
* using HTTP/1.x
> GET / HTTP/1.1
> Host: http-server:8000
> User-Agent: curl/8.21.0
> Accept: */*
> 
* Request completely sent off
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Server: SimpleHTTP/0.6 Python/3.13.15
< Date: Fri, 04 Sep 2026 10:33:05 GMT
< Content-type: text/html; charset=utf-8
< Content-Length: 809
< 
...
* shutting down connection #0

I understand that passing the configured domain in both --dns-search options and a longer FQDN like id/name takes a lot of typing and is far from ideal, but if it is already possible, maybe it should be documented? At least in the skills, since a coding agent should not mind the extra "typing"?

[saehejkang]

This will live better in Issues for better visibility. Feel free, for small things or asks like this, to create a new Future or enhancement request and open up a PR with the solution/update.

[l-hedgehog]

Opened as #2239, thanks for the advice!