Where can I find config file for Ubuntu 18.04 LXC container?

I am trying to test LXC container and created Ubuntu 18.04 container. To access these container from Host Network machines I created new bridged interface in host /etc/network/interfaces and wanted to modify /var/lib/lxc/container-name/config to provide lxc.network.link, lxc.network.ipv4/6, lxc.network.ipv4/6, lxc.network.veth.pair etc. but to my surprise I’m not able to find the config file at this location. though, I can see default.config file at /etc/lxc.

If i update default.config with lxc.network.link and allow newly created containers to get the IP from DHCP will it work? for creating new container I am using “lxc launch ubuntu:18.04”

https://linuxcontainers.org/lxc/manpages/man5/lxc.conf.5.html
" A basic configuration is generated at container creation time with the default’s recommended for the chosen template as well as extra default keys coming from the default.conf file."
Not sure where this container specific configuration file gets created.

Thanks for any help in Advance!

Hello

do you want to use plain LXC or LXD ? if the latter, it generally works without any config file.
Differences between LXC and LXD are explained here

LXD.
So where would I need to change if I need to instruct the container to use different bridge interface then the default one ‘lxcbr0’?
lxc.network.link = lxcbr0 to br0

The default bridge interface for LXD is lxDbr0, not lxcbr0.

Please forgive the lack of knowledge of containers. just started learning.
Yes, it is lxdbr0.
Does my question still stand?

you may find more answers to your questions if you take more time to formulate them. One can feel tired to try to reply to ambiguous questions. Do you mean this ? or that ? or something else ? It’s quicker to just not give any answer.

Anyway, I have no experience on using another bridge since the default one does its job and I see absolutely no reason to use another. I had success on adding to default devices such as a secondary ethernet card, though. I have done it by creating a specific profile (lxc profile) and editing the new profile and adding the new card, like this

eth1:
  name: red0
  nictype: macvlan
  parent: usbnet0
  type: nic

but you could certainly do the same by adding the device directly to a container. Yeah, this can be done:

lxc config device --help
Description:
Manage container devices

Usage:
  lxc config device [command]

Available Commands:
  add         Add devices to containers or profiles