Pi startup fix

[amquake]

Fixes #917

I just made a quick hacky fix that caches the interface read ("nmcli -t -f GENERAL.CONNECTION,GENERAL.DEVICE,GENERAL.TYPE device show") to once every 5 seconds since it gets called a lot. Not sure if this could cause problems (does this shell command return new values depending on e.g. new ethernet connections? or does that fall under getAllActiveInterfaces() filtering?). Still don't like how this can cause this error in the first place, but I'm not sure how to get more info about that.

[mcm001]

In what way exactly does this fix it? (just like document it)

[mcm001]

Does this caching change actually fix the startup loop?

[amquake]

Does this caching change actually fix the startup loop?

Yes, at least on my pi. As mentioned in the issue, I'm guessing the network manager shell commands are blocking the camera use in libcamera somehow which causes it to crash. This just caches the shell command for listing network interfaces so it doesn't happen several times rapidly while booting up.

[mcm001]

I wonder what would happen if the pi boots before the radio. Does the Ethernet connection actually show up and get managed?

[amquake]

I wonder what would happen if the pi boots before the radio. Does the Ethernet connection actually show up and get managed?

From what I've understood, the NetworkTablesManager will keep trying to restart the NT client until it connects, which is separate from NetworkManager managing hostname and dhcp/static. The NetworkManager will only initialize these on bootup and when general settings are saved. The network interfaces will additionally be updated when a new websocket connects, new camera connects, or settings are broadcasted/loaded.

I'm assuming the configuration done in the NetworkManager initialize is redundant when deserializing a previously setup NetworkConfig, so not having the interface on bootup wouldn't be a problem. It would only be a problem if the NetworkConfig wasn't previously initialized, since NetworkManager won't reinitialize when it finds an active interface and you might not be able to connect without that initialization.

Does that sound right?

[mcm001]

NetworkManager

Yep, from a quick glance through the code, the link state at boot once configured shouldn't matter. LGTM, send it and see if it breaks