Hi Eirikur. Not sure what details you'll need, so here's both the details of my default profile, which has been edited from the default, and the config settings. The changes to the profile were so that the container uses my router as the dns, rather than the host (I recall having to change my network adapters settings to set that up as well).
thom@ihy:~$ lxc profile show default
config:
limits.memory: 2048MB
description: Default LXD profile
devices:
eth0:
  name: eth0
  nictype: bridged
  parent: br0
  type: nic
root:
  path: /
  pool: default
  type: disk
name: default
used_by:
- /1.0/containers/qebui
thom@ihy:~$ lxc config show qebui
architecture: x86_64
config:
image.architecture: amd64
image.description: ubuntu 16.04 LTS amd64 (release) (20180427)
image.label: release
image.os: ubuntu
image.release: xenial
image.serial: "20180427"
image.version: "16.04"
volatile.base_image: 353b1a2c367ec983fd9d1532171618cd967e96d77a06f6b6e024c39ec010e8d7
volatile.eth0.hwaddr: 00:16:3e:78:5b:f0
volatile.idmap.base: "0"
volatile.idmap.next: '[{"Isuid":true,"Isgid":false,"Hostid":165536,"Nsid":0,"Maprange":65536},{"Isuid":false,"Isgid":true,"Hostid":165536,"Nsid":0,"Maprange":65536}]'
volatile.last_state.idmap: '[{"Isuid":true,"Isgid":false,"Hostid":165536,"Nsid":0,"Maprange":65536},{"Isuid":false,"Isgid":true,"Hostid":165536,"Nsid":0,"Maprange":65536}]'
volatile.last_state.power: RUNNING
devices: {}
ephemeral: false
profiles:
- default
stateful: false
description: ""

The specific command I used to create the container was:
lxc launch ubuntu:16.04 qebui
From there I followed the instructions in the document on how to install SQL Server on Linux: https://docs.microsoft.com/en-us/sql/linux/quickstart-install-connect-ubuntu?view=sql-server-linux-2017

Feel free to give me a shout if you get stuck. Just let me know the errors you have. 🙂

Cheers!