Isolate systemd user network namespace from host

Signed-off-by: Anders F Björklund <[email protected]>

Author: afbjorklund

examples/systemd/user/buildkit.service

@@ -5,7 +5,7 @@ Documentation=https://github.com/moby/buildkit
 [Service]
 Type=notify
 NotifyAccess=all
-ExecStart=rootlesskit /usr/local/bin/buildkitd --addr unix://%t/buildkit/rootless
+ExecStart=rootlesskit --net=slirp4netns --copy-up=/etc --disable-host-loopback /usr/local/bin/buildkitd --addr unix://%t/buildkit/rootless
 
 [Install]
 WantedBy=multi-user.target