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LXC with LXD on an Ubuntu 16.04 server

See official and other docs and guides:

Intro

Using the linux container system LXC with LXD extension, the LXD extension adds parts like an easier API for LXC and handles networks a little bit nicer.

Prepare the system

apt update && apt upgrade -y && \\
apt install htop lxc debootstrap bridge-utils -y && \\
apt install -t xenial-backports lxd lxd-client -y;

Before first run, lxd needs to be configured with

lxd init

within this the basic settings are set. Like on what storage pool with what driver the containers should be created and stored.

Also a network bridge could be configured, don't confuse it with Would you like LXD to be available over the network - this is about if the LXD API should be available through a defined port from the local network. Don't worry, you can skip the network bridge now and configure it later.

Creation

Image

What images of ubuntu are available

lxc image list ubuntu:

which alias names exists for the images

lxc image alias list ubuntu:

and see all images

lxc image list images:

Launch

Creates first container with ubuntu:16.04 server and starts it

lxc launch ubuntu:16.04 containername

this creates but does not start the container, init and launch are swappable

lxc init ubuntu:16.04 containername

When not already started, starts container

lxc start containername

Execution

Switch into root shell of container

lxc exec containername -- /bin/bash

You can go back to the host with halt, this shuts the container down too or simply with exit.

Killing

Hard stop of container

lxc stop containername

Delete the container

lxc delete containername

Profiles

Show profiles of containers, default will be used for all containers, which didn't launch with a specific config.

Network

LXD Network

Lists existing LXC network bridges

lxc network list

Edit a network profile

lxc network edit profilename

Create a network profile

lxc network create profilename

Attach a network profile to a container profile

lxc network attach-profile profilename containerprofilename

Example

lxc network create br0
lxc network edit br0

# add this config or like that
config:
    dns.mode: dynamic
    ipv6.address: none
    ipv4.address: 10.10.10.1/24
    ipv4.nat: true
    ipv4.dhcp: true
description: ""
name: br0
type: bridge
used_by: []
managed: true

lxc network attach-profile br0 default

Synopsis

apt update && apt upgrade -y && apt install htop lxc debootstrap bridge-utils -y && apt install -t xenial-backports lxd lxd-client -y;

# do not create network within init
lxd init

lxc network list

# create network like in network example

lxc launch ubuntu:16.04 containername

lxc start containername && \\
lxc exec containername -- /bin/bash

exit

lxc stop containername

Host Network:

  • Workstation IP 192.168.178.94
  • LXC-Host IP 192.168.178.35
  • Gateway 192.168.178.1
  • DNS 192.168.178.1

When the container is running now:

  • the bridge br0 has the IP 10.10.10.1 and ?LXD runs an DNS server on it?
  • the container has an IP like 10.10.10.*
  • the container could access the internet through the host gateway
  • the container could ping and curl the workstation with it's IP
  • the host could ping the container
  • the host could ping br0
  • the workstation can't ping or curl the container
  • the workstation can't ping br0

When ipv4.address: 10.10.10.1/24 is set to 192.168.178.2/24:

  • the bridge br0 has the IP 192.168.178.2
  • the container has an IP like 192.168.178.*
  • the container can't access the internet through the host gateway
  • the container can't ping and curl the workstation with it's IP
  • the host can't ping the container
  • the host could ping br0
  • the workstation can't ping or curl the container
  • the workstation could ping br0

Added ipv4.routes: 192.168.178.1/24:

  • no changes

When changing dns.mode: dynamic to dns.mode: managed the container is generally not available from the network, it seems.

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