--domainname on the container sets the kernel domainname, which c-ares
uses to infer a search domain even when /etc/resolv.conf has no search
line. This caused c-ares to query github.com.casjay.work AAAA and get
the host's own IPv6 address, routing all outbound HTTPS to the local
nginx instead of the real server.
Adding 'search .' and 'options ndots:0' explicitly disables search
domain inference regardless of the kernel domainname setting.
- rootfs/usr/local/etc/resolv.conf: add search . and options ndots:0
rootfs/usr/local/etc/resolv.conf
Hosts with a search domain cause containers to inherit it. When the
zone has a wildcard AAAA record, public hostnames resolve to the host's
own IPv6 address instead of the real server, breaking all outbound
HTTPS and DNS from inside the container.
The entrypoint already has a hook: if /usr/local/etc/resolv.conf
exists it replaces /etc/resolv.conf at container startup. Ship a
clean resolv.conf with Cloudflare + Google DNS and no search domain
so container DNS is always correct regardless of host configuration.
- rootfs/usr/local/etc/resolv.conf: new file — clean DNS, no search domain
rootfs/usr/local/etc/resolv.conf
jason
