Proxy device does not redirect port 80 on my Raspberry

Hello. On my server (Funtoo OS) I am using LXD 3 (no Snap) and I can redirect port 80 to LAN with this:

lxc config device add containername myproxy80 proxy listen=tcp:0.0.0.0:80 connect=tcp:127.0.0.1:80

And I can access Apache Server from another computer on my LAN. I can see the port too:

localhost ~ # netstat -an | grep LISTEN | grep 80
tcp6 0 0 :::80 :::* LISTEN
tcp6 0 0 fe80::45f:38ff:fea6::53 :::* LISTEN
tcp6 0 0 fe80::c61d:1824:14e9:53 :::* LISTEN

But with this same setup (LXD 3 with Snap) on my Raspberry Pi (Ubuntu Server 20.04), adding the same proxy device doesn’t work, I can not see the port listening, and I can not access to apache from another computer:

ubuntu@ubuntu:~$ netstat -an | grep LISTEN | grep 80
tcp6 0 0 fe80::bc3c:e4ff:fe3b:53 :::* LISTEN
unix 2 [ ACC ] STREAM LISTENING 38807 @/org/kernel/linux/storage/multipathd
unix 2 [ ACC ] STREAM LISTENING 38805 /run/lvm/lvmpolld.socket

Can you help me or give me a hint please?

Can you show ps fauxww and any relevant log from /var/snap/lxd/common/lxd/logs/containername/?

For sure!

ps fauxww: https://pastebin.com/qQUa25nq
/var/snap/lxd/common/lxd/logs/containername/lxc.log: https://pastebin.com/c0ZUV5jK
/var/snap/lxd/common/lxd/logs/containername/proxy.myproxy80.log: https://pastebin.com/puEmshmv
/var/snap/lxd/common/lxd/logs/containername/console.log: https://pastebin.com/TSUa8hWf

I think that in those files there is relevant information. I only extracted the parts that I think are relevant.

I have switched from Ubuntu Server 20.04 to Ubuntu Core 18, and installed LXD 3 and I have the same problem.

Investigating, I realized that stgraber comments that this error with the proxy device occurs in version 3.0.4 (which is the one I have) and was fixed in later version 3.0.5. This comment can be found here: Ubuntu 19.04 proxy dev fail, "read-only filesystem"

I wanted to ask you if this deduction that I have obtained is correct, and if so, It is possible to install 3.21 version as snap? On my Funtoo Linux I have that version, but on my Raspberry with Ubuntu Core or Ubuntu Server 20.04 the last version I can see with “snap info lxd” is 3.0.4.

You can try and use the LXD snap 4.0/stable channel as this should have the fix too as it is more frequently updated.