Ubios discover fails after restart on UDM

[cleidich]

I've noticed that discovery of client names from UnifiOs/Ubios fails on the first run of ctrld after my UDM is restarted. This has been happening since at least v1.3.10 of ctrld and v4.0.20 of UnifiOS; although it may have been occurring for longer and I just didn't notice it. Unfortunately I can't confirm the exact start date/versions.

When ctrld starts after a device restart (either a true power off/power on or just a software reboot), I do see an error logged about Ubios discovery failing to initialize:
{"level":"error","error":"exit status 1","time":"2025-01-06T13:45:20-05:00.759","message":"could not init Ubios discover"}

If I restart the ctrld daemon, UnifiOS discovery will work properly. I'm positing that this is just a case of the discovery init occurring too early in the boot process although I can't be certain. Perhaps a fix is to just have the init re-attempt every x minutes until successful, etc.

This doesn't cause any resolution issues, but does mean that I get some duplicate clients for that endpoint as the clients get reported using another discovered name (usually via PTR or mDNS) until I restart ctrld, at which point they report using their UbiOS names again.

A full debug log after a recent restart is below; I don't see a lot that says why the discovery init is failing but I am happy to do additional testing and debugging if it helps.

Full log

{"level":"info","time":"2025-01-06T13:45:16-05:00.141","message":"starting ctrld v1.3.11"}                              {"level":"info","time":"2025-01-06T13:45:16-05:00.261","message":"os: linux Debian GNU/Linux 11 (bullseye) (4.19.152-ui-alpine)"}                                                                                                               {"level":"debug","time":"2025-01-06T13:45:20-05:00.433","message":"control server started: /var/run/ctrld_control.sock"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.435","message":"resolving \"dns.controld.com\" using bootstrap DNS [\"76.76.2.22:53\" \"[fe80::201:5cff:fe6b:2a46]:53\"]"}                                                                   {"level":"error","error":"dial udp 76.76.2.22:53: connect: network is unreachable\ndial udp [fe80::201:5cff:fe6b:2a46]:53: connect: invalid argument","time":"2025-01-06T13:45:20-05:00.436","message":"could not lookup \"AAAA\" record for domain \"dns.controld.com\""}                                                                                              {"level":"error","error":"dial udp [fe80::201:5cff:fe6b:2a46]:53: connect: invalid argument\ndial udp 76.76.2.22:53: connect: network is unreachable","time":"2025-01-06T13:45:20-05:00.436","message":"could not lookup \"A\" record for domain \"dns.controld.com\""}                                                                                                 {"level":"warn","time":"2025-01-06T13:45:20-05:00.436","message":"could not resolve bootstrap IPs, retrying..."}        {"level":"debug","time":"2025-01-06T13:45:20-05:00.446","message":"resolving \"dns.controld.com\" using bootstrap DNS [\"76.76.2.22:53\" \"[fe80::201:5cff:fe6b:2a46]:53\"]"}                                                                   {"level":"error","error":"dial udp 76.76.2.22:53: connect: network is unreachable\ndial udp [fe80::201:5cff:fe6b:2a46]:53: connect: invalid argument","time":"2025-01-06T13:45:20-05:00.446","message":"could not lookup \"AAAA\" record for domain \"dns.controld.com\""}
{"level":"error","error":"dial udp 76.76.2.22:53: connect: network is unreachable\ndial udp [fe80::201:5cff:fe6b:2a46]:53: connect: invalid argument","time":"2025-01-06T13:45:20-05:00.446","message":"could not lookup \"A\" record for domain \"dns.controld.com\""}
{"level":"warn","time":"2025-01-06T13:45:20-05:00.447","message":"could not resolve bootstrap IPs, retrying..."}        {"level":"debug","time":"2025-01-06T13:45:20-05:00.481","message":"resolving \"dns.controld.com\" using bootstrap DNS [\"76.76.2.22:53\" \"[fe80::201:5cff:fe6b:2a46]:53\"]"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.521","message":"got answer from nameserver: 76.76.2.22"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.545","message":"got answer from nameserver: 76.76.2.22"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.545","message":"bootstrap IPs: [2606:1a40::22 76.76.2.22]"}
{"level":"info","time":"2025-01-06T13:45:20-05:00.545","message":"bootstrap IPs for upstream.0: [\"2606:1a40::22\" \"76.76.2.22\"]"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.547","message":"resolving \"dns.controld.com\" using bootstrap DNS [\"76.76.2.22:53\" \"[fe80::201:5cff:fe6b:2a46]:53\"]"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.574","message":"got answer from nameserver: 76.76.2.22"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.594","message":"got answer from nameserver: 76.76.2.22"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.594","message":"bootstrap IPs: [2606:1a40::22 76.76.2.22]"}
{"level":"info","time":"2025-01-06T13:45:20-05:00.594","message":"bootstrap IPs for upstream.1: [\"2606:1a40::22\" \"76.76.2.22\"]"}
{"level":"info","bootstrap_ip":"8.8.8.8","time":"2025-01-06T13:45:20-05:00.594","message":"using bootstrap IP for upstream.2"}
{"level":"info","time":"2025-01-06T13:45:20-05:00.594","message":"starting DNS server on listener.0: 0.0.0.0:5354"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.595","message":"router setup on start"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.595","message":"start checking DNS loop"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.595","message":"skipping external: upstream.0"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.595","message":"skipping external: upstream.1"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.595","message":"skipping external: upstream.2"}
{"level":"debug","time":"2025-01-06T13:45:20-05:00.595","message":"end checking DNS loop"}
{"level":"debug","iface":"lo","time":"2025-01-06T13:45:20-05:00.604","message":"Restoring DNS for interface"}
{"level":"error","error":"exit status 1","time":"2025-01-06T13:45:20-05:00.759","message":"could not init Ubios discover"}