I think it's failing as the output 'OpenSec' is None for APP-secgroup.template.yaml, before the nested stack is created. When you are creating a list it's creating a list like '[None]'.
You can work around this by changing the following in APP-secgroup.template.yaml:
......
OpenSec:
description: Open security group.
value: [{ get_resource: APP-open-sec }]
I think it's failing as the output 'OpenSec' is None for APP-secgroup. template. yaml, before the nested stack is created. When you are creating a list it's creating a list like '[None]'.
You can work around this by changing the following in APP-secgroup. template. yaml:
......
OpenSec:
description: Open security group.
value: [{ get_resource: APP-open-sec }]
and then in hot.yaml don't create a list
APP- server01pair:
eth0_ sec_groups: {get_attr: [APPnetworking, OpenSec]}
type: APP::VmPair
depends_on:
- APPnetworking
properties:
.....
At least this works with master. I'll check how it used to work in Juno.