Use get_attr on the server resource to resolve attribute
value from the subnet(s) and pass it to the parameter
'ControlPlaneDefaultRoute' used in the THT/network/config/*
templates.
Changes the default for 'ControlPlaneDefaultRoute' to ''
as well as the comment that the value should be overriden
in parameters_defaults. It also removes the parameter from
network-environment templates.
A conditinal is used in puppet/role.role.j2.yaml so that
the parameter value is used whenever it is not '' (the
default) to provide backwards compatibility in case the
user set a different value (different from the one used in
undercloud.conf) for this parameter in
network-environment.yaml.
When deploying a routed control plane the network config
templates would previously need to be updated to carry
'ControlPlaneXDefaultRoute' parameters for each leaf. With
8 Leafs in addition to the network local to the undercloud
that is 8 parameters less to place in the configuration.
By getting the value to pass from the server resource this
change reduces the required nic-config template
customisation (reduces the risk of user error).
Partial: blueprint tripleo-routed-networks-templates
Change-Id: I5139249d55e9ac01761c270b8c0f31ef35595940
c649cf0545