Lxd init with preseed - help needed to get it right

LXD
1

I’m trying to use a preseed to use with the lxd juju charm:

The file format is documented here: Non-interactive configuration via preseed YAML - LXD documentation

Like this:

juju deploy ch:lxd --num-units 1 --config snap-channel="5.0/stable" --config lxd-listen-https=true --config lxd-listen-metrics=true --config lxd-preseed="$(cat preseed.yaml)"

However, I would like to test the preseed first. So I have prepared my server:

  • I have created the br0 bridge in the host.
  • I have created the zpool default

This is my preseed.yaml:

config:
networks:
- name: br0
  type: bridge
  config:
    ipv4.address: auto
    ipv6.address: none
storage_pools:
- name: default
  driver: zfs
  config:
    source: default

When I run:

lxd init --preseed < /home/ubuntu/preseed.yaml 
Error: Failed to update local member network "br0" in project "default": Network not found

What am I doing wrong?

I need to craft a preseed to work with the juju charm…

2

@sdeziel

3

I’ve expanded the config to test if I was needing more, but no luck with this either. Same error as above.

config:
    core.trust_password: 1234
networks:
- name: br0
  type: bridge
  config:
    ipv4.address: none
    ipv6.address: none

storage_pools:
- name: default
  driver: zfs
  config:
    zfs.pool_name: default
    source: default
    volatile.initial_source: default

profiles:
- name: default
  devices:
    root:
      path: /
      pool: data
      type: disk
  eth0:
    name: eth0
    nictype: bridged
    parent: br0
    type: nic

projects:
- config:
    features.images: "true"
    features.networks: "true"
    features.profiles: "true"
    features.storage.volumes: "true"
  description: Default LXD project
  name: default
4

If you are creating the br0 network in the host, LXD shouldn’t manage it directly. You could still make use of it by referencing it in your default profile for example.

5

This seemed to work, but my container doesn’t get a network from this:

$ lxc launch ubuntu:20.04 first
Creating first
                                          
The instance you are starting doesn't have any network attached to it.
  To create a new network, use: lxc network create
  To attach a network to an instance, use: lxc network attach

Starting first
$ lxc list      
+-------+---------+------+------+-----------+-----------+
| NAME  |  STATE  | IPV4 | IPV6 |   TYPE    | SNAPSHOTS |
+-------+---------+------+------+-----------+-----------+
| first | RUNNING |      |      | CONTAINER | 0         |
+-------+---------+------+------+-----------+-----------+

The network seems to be there.

$ lxc network list
+---------+----------+---------+------+------+-------------+---------+-------+
|  NAME   |   TYPE   | MANAGED | IPV4 | IPV6 | DESCRIPTION | USED BY | STATE |
+---------+----------+---------+------+------+-------------+---------+-------+
| br0     | bridge   | NO      |      |      |             | 0       |       |
+---------+----------+---------+------+------+-------------+---------+-------+
| eno1np0 | physical | NO      |      |      |             | 0       |       |
+---------+----------+---------+------+------+-------------+---------+-------+
| eno2np1 | physical | NO      |      |      |             | 0       |       |
+---------+----------+---------+------+------+-------------+---------+-------+

This is my current preseed.yaml

config:
    core.trust_password: 1234

storage_pools:
- name: default
  driver: zfs
  config:
    zfs.pool_name: default
    source: default
    volatile.initial_source: default

profiles:
- name: default
  devices:
    root:
      path: /
      pool: default
      type: disk
  eth0:
    name: eth0
    nictype: bridged
    parent: br0
    type: nic

projects:
- config:
    features.images: "true"
    features.networks: "true"
    features.profiles: "true"
    features.storage.volumes: "true"
  description: Default LXD project
  name: default

Do I have to do something to reload the config or something after I run:

lxd init --preseed myconf.yaml

Is it safe to run it over and over for my testing or does lxd need something to reset the config after I run this multiple times for testing my config?

6

This is strange.

I tried adding the network manually via “lxd config edit default”, tested that it worked then did a “lxd init --dump > my-working-preseed.yaml”.

I then re-ran with the old preseed: “lxd init --preseed my-old-preseed.yaml” and then it also worked.

Now I’m unable to reproduce the error above.

Is this some bug?

7

How can I reset my lxd entirely to see if I can reproduce from a clean slate? I’m using snap.

8

If you don’t mind losing your instances and all config:

sudo snap remove --purge lxd
sudo snap install lxd
9

If you can reproduce the issue then I would like to see the output of:

  • ip a and ip r on the host and inside the instance using the profile.
  • lxc config show <instance> --expanded
10

I don’t mind at all losing the config as I’m testing now.

Also, I have to empty the ZFS pool used in my preseed with something like this or the preseed will complain that the pool is not empty:

zfs destroy default/*

This is useful to know for anyone trying to reset to test automation etc. OR is there a way to reuse an already existing ZFS pool? That would be good to know also.

1 Like
11

Yes good point. There isn’t a reuse_existing setting for ZFS pools.

1 Like