LXC containers failing to download packages through http-proxy

I’m attempting to deploy openstack-base-70 on a set of 5 servers with identical network configurations.

Server 1 - MaaS Rack+Region controller
Server 2 - Juju controller
Servers 3-5 - Openstack installation targets.

There are two networks: eno1(10.0.33.x/24) is an air-gapped network, and eno2 has access to the internet. When i deploy the openstack bundle, LXC containers are given an address on the 10.0.33.x network. The installation fails on container setup (‘hook failed: install’). Checking the cloud-init logs in the containers shows that they are unable to connect and download apt repositories.

The 10.0.33.x network is configured in MaaS to use the region controller as an http proxy on ports 3128/8000, but packet captures do not show any traffic coming from the containers to those ports on the region controller. Am I missing something in my configuration? If I can’t get the http proxy to work, could I somehow have the LXC containers created on the second network (eno2, w/ internet access)?