Cloud in a Box Issue - LXD static host with DHCP bridge and static LXD host reservations

Question

I have a host (Openstack Newton data center controller) with the following services running on it:

• Maas-Rack-Controller (bridge DHCP)
• Cloudify (multi-cloud management POC)
• Juju (cant bootstrap yet...)

These are running as LXD containers on ZFS. The hardware is an Intel NUC 5i5MYHE blade with an SSD drive. The blade is fed a set of VLAN trunks with the first VLAN untagged. This untagged LVAN is our core data center network. I have a Maas-Region-Controller upstream that communicates to the rack controller and manages it.

MaaS has a DHCP reservation excluding the first 10 IP addresses on this network for these core services, and is set to assign addresses from a DHCP pool to LXD Openstack components on my other blades over the untagged VLAN when they PXE boot to the internal rack controller.

I can easily set the LXD bridge interface IP address to DHCP since I technically do not care about it, but the controller host that all of this lives on needs a static address in the reserved range.

Juju will need a DHCP assignment to be able to complete it's bootstrap process.

I am searching for something like this, although this doesn't work for obvious reasons:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface

iface enp0s25 inet manual
        address 192.168.199.5
        netmask 255.255.255.0
        network 192.168.199.0
        broadcast 192.168.199.255
        gateway 192.168.199.1
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 192.168.199.1 192.168.1.1 8.8.8.8
        dns-search home.spyderdyne.net

auto br0
iface br0 inet dhcp
       bridge-ifaces enp0s25
       bridge-ports enp0s25
       up ifconfig enp0s25 up

Any thoughts on a way to allow DHCP across the bridge with a blade having a static IP and not breaking VLANs are welcome. I am thinking about some sort of sub-interface definition maybe.

Obviously this is not covered anywhere that I can find and probably represents an odd setup, but I am trying to make the most of limited resources and space for this project.

Answer 1

I figured it out. Here are the steps:

Step 1. Enable DHCP on your network somehow. For this I changed my router from a DHCP forwarder to a DHCP server.

Step 2. Set up a bridge device on the "controller" server with your manual (static) address in /etc/network/interfaces.

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface

auto br0
iface br0 inet static
       address 192.168.199.5
       netmask 255.255.255.0
       gateway 192.168.199.1
       dns-nameservers 192.168.199.2 192.168.199.1 192.168.1.1
       dns-search home.spyderdyne.net
       bridge-ifaces enp0s25        
bridge-ports enp0s25
        up ifconfig enp0s25 up

iface enp0s25 inet manual

Step 3. Record the hardware/MAC address of your new bridge device:

root@rack2-controller0:~# ifconfig br0
br0: flags=4163  mtu 1500
        inet 192.168.199.5  netmask 255.255.255.0  broadcast 192.168.199.255
        inet6 fe80::baae:edff:fe7f:fd70  prefixlen 64  scopeid 0x20
        ether b8:ae:ed:7f:fd:70  txqueuelen 1000  (Ethernet)
        RX packets 315449  bytes 353143957 (353.1 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 217291  bytes 16267645 (16.2 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Step 4. Configure your DHCP server to assign that correct static IP address you want to assign to the bridge device:

Step 5. Install LXD:

root@rack2-controller0:~# lxd init
Name of the storage backend to use (dir or zfs) [default=zfs]: 
Create a new ZFS pool (yes/no) [default=yes]? 
Name of the new ZFS pool [default=lxd]: 
Would you like to use an existing block device (yes/no) [default=no]? yes
Path to the existing block device: /dev/sda2
Would you like LXD to be available over the network (yes/no) [default=no]? yes
Address to bind LXD to (not including port) [default=all]: 
Port to bind LXD to [default=8443]: 
Trust password for new clients: 
Again: 
Would you like stale cached images to be updated automatically (yes/no) [default=yes]? 
Would you like to create a new network bridge (yes/no) [default=yes]? no
LXD has been successfully configured.

Step 6. Edit you default LXD profile network config to include the bridge:

root@rack2-controller0:~# lxc profile edit default

### This is a yaml representation of the profile.
### Any line starting with a '# will be ignored.
###
### A profile consists of a set of configuration items followed by a set of
### devices.
###
### An example would look like:
### name: onenic
### config:
###   raw.lxc: lxc.aa_profile=unconfined
### devices:
###   eth0:
###     nictype: bridged
###     parent: lxdbr0
###     type: nic
###
### Note that the name is shown but cannot be changed

name: default
config: {}
description: Default LXD profile
devices:   
    eth0:
        nictype: bridged
        parent: br0

Step 7. Launch a new container instance:

root@rack2-controller0:~# lxc launch ubuntu:yakkety rack2-maas-rack0
Creating rack2-maas-rack0
Retrieving image: 100%
Starting rack2-maas-rack0
root@rack2-controller0:~# lxc list
+------------------+---------+------+------+------------+-----------+
|       NAME       |  STATE  | IPV4 | IPV6 |    TYPE    | SNAPSHOTS |
+------------------+---------+------+------+------------+-----------+
| rack2-maas-rack0 | RUNNING |      |      | PERSISTENT | 0         |
+------------------+---------+------+------+------------+-----------+

Step 8. Set the new container's network settings to the desired static address:

root@rack2-maas-rack0:~# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# Source interfaces
# Please check /etc/network/interfaces.d before changing this file
# as interfaces may have been defined in /etc/network/interfaces.d
# See LP: #1262951
#source /etc/network/interfaces.d/*.cfg

auto eth0
iface eth0 inet static
        address 192.168.199.6
        netmask 255.255.255.0
        gateway 192.168.199.1
        dns-nameservers 192.168.199.1 192.168.1.1 8.8.8.8

Step 9. Install maas-rack-controller:

apt install -y maas-rack-controller

Step 10. Add the new Rack controller to your region controller:

root@rack2-maas-rack0:~# maas-rack register --url=http://192.168.199.2/5240/MAAS --secret=e613b300be30450c07a724ac77819aae

Step 11. Wait for the new rack controller to sync with the rest of the region:

Step 12. Disable DHCP on your OTHER DHCP server:

Step 13. Configure MaaS DHCP:

Step 14: Add DHCP reservations if needed.

Step 15. Manually configure hosts by MAC address to set static addresses via DHCP, or at least preserve their addresses from future allocation.

I will have to wait for the new rack controller to finish it''s sync operations before I can tell for sure that rack DHCP is working, but at least I have manual addresses up and running, and should be able to run the DHCP server now.