Having ubuntu 20.4 packaged dnscrypt-proxy listen on 127.0.0.1:53 and

[lestephane]

canonical livepatch activation seems to require a DNS service running at 127.0.0.1 port 53, but the dnscrypt-proxy package available in ubuntu 20.04 repositories uses 127.0.2.1. So I tried the following:

$ vim /etc/dnscrypt-proxy.toml
...
listen_addresses = ['127.0.0.1:53', '[::1]:53']
...
$ vim /lib/systemd/system/dnscrypt-proxy.socket
...
[Socket]
ListenStream=127.0.0.1:53
ListenStream=[::1]:53
ListenDatagram=127.0.0.1:53
ListenDatagram=[::1]:53
...
...

And still got permission denied bind errors in the logs upon systemctl restart dnscrypt-proxy

Any idea how to do this correctly?

There are no other processes listening to port 53 at any of these two loopback addresses:

$ sudo netstat -tulpen | grep -E ":53\W"
tcp        0      0 127.0.2.1:53            0.0.0.0:*               LISTEN      0          285394     1/init              
tcp        0      0 127.0.0.53:53           0.0.0.0:*               LISTEN      101        43014      1136/systemd-resolv 
udp        0      0 127.0.2.1:53            0.0.0.0:*                           0          285396     1/init              
udp        0      0 127.0.0.53:53           0.0.0.0:*                           101        43013      1136/systemd-resolv 

The package version in question:

$ dpkg -s dnscrypt-proxy | grep Version
Version: 2.0.31+ds1-1

[lestephane]

I suspect this is also the reason Chromiun complains with DNS_PROBE_FINISHED_BAD_CONFIG, because of dnscrypt-config not listening on 127.0.0.1:53, but it's only a suspicion at this point.