docker0 bind error spam

[GamePlayer-8]

Yggdrasil node is spamming yggdrasil[5177]: 2024/10/20 10:19:16 Not multicasting on docker0 due to error: listen tcp [fe80::1%docker0]:0: bind: cannot assign requested address in the /var/log/messages every second.

[neilalexander]

If your Docker installation doesn't have IPv6 enabled then you can just disable multicasting by setting Listen and Beacon under MulticastInterfaces to false.

[GamePlayer-8]

It actually does:

/etc/docker/daemon.json

{
  "ipv6": true,
  "fixed-cidr-v6": "fd12:3452:789a:1::/64",
  "experimental": true,
  "ip6tables": true,
  "dns": ["192.168.4.100"],
  "log-opts": {
        "max-size": "10m",
        "max-file": "1"
  },
  "storage-driver": "overlay2",
  "builder": {
	"Entitlements": {
		"security-insecure": true
	}
  }
}

will disable the listening in the Yggdrasil config

[neilalexander]

I don't really know Docker's bridge networking well enough to understand why it would be trying to assign fe80::1 as a link-local address as opposed to a normal generated one, or why if it had assigned it that it wouldn't be listenable.

Yggdrasil just tries to select a link-local address to use from interfaces that are up and connected, and it does so continuously to respond to changes in network links, i.e. a network cable or Wi-Fi network connects/disconnects.

That said there's every possibility that multicast discovery won't really work properly under Docker anyway, in which case you may just want to disable it anyway.

[GamePlayer-8]

Any way to add an exception / timed out on retries function on ports/interfaces which are misbehaving towards adding the multicast listener?

[GamePlayer-8]

Solution is to use RegEx: "^([^d]|d[^o]|do[^c]|doc[^k]|dock[^e]|docker[^a-zA-Z0-9_]).*$" inside MulticastInterfaces.

When using "^(?!docker).*" the Perl interpreter fails with:

panic: regexp: Compile(`^(?!docker).*`): error parsing regexp: invalid or unsupported Perl syntax: `(?!`
goroutine 1 [running]:
        /opt/hostedtoolcache/go/1.20.13/x64/src/regexp/regexp.go:319 +0xbb
main.main()
        /home/runner/work/yggdrasil-go/yggdrasil-go/cmd/yggdrasil/main.go:245 +0x1fc9