MaaS: Add support for dynamic fabric numbering

Previously, we hardcoded the fabric name for our 3rd interface
(which serves PXE/DHCP for the target nodes) to "fabric-2",
relying on predictable index numbers to be provided by MaaS based
on the interfaces defined in /etc/network/interfaces.

However, the fabric IDs/names generated by MaaS are not predictable,
and therefore cannot be hardcoded in our reclass model / scripts.

Work around this by:
- adding support for fabric ID deduction based on CIDR matching
  during subnet create/update operation in MaaS py module;
- adding support for VLAN DHCP enablement to MaaS py module,
  which was previously handled via shell MaaS API operations
  from maas/region.sls;

While at it, revert previous commit that disabled network discovery
("MaaS: Disable network discovery"), since it turns out that network
discovery was not the culprit for subnet creation failure, but wrong
fabric numbering.

This reverts commit 8cdf22d1a1bae4694a373873cab4feb6251069b7.

Change-Id: I15fa059004356cb4aaabb38999ea378dd3c0e0bb
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/mcp/reclass/classes/cluster/baremetal-mcp-ocata-ovs-ha/infra/maas.yml b/mcp/reclass/classes/cluster/baremetal-mcp-ocata-ovs-ha/infra/maas.yml
index cebcb90ae..d193469fc 100644
--- a/mcp/reclass/classes/cluster/baremetal-mcp-ocata-ovs-ha/infra/maas.yml
+++ b/mcp/reclass/classes/cluster/baremetal-mcp-ocata-ovs-ha/infra/maas.yml
@@ -29,18 +29,22 @@ parameters:
         disk_erase_with_secure_erase: false
         dnssec_validation: 'no'
         enable_third_party_drivers: true
-        network_discovery: 'disabled'
+        network_discovery: 'enabled'
         default_min_hwe_kernel: 'hwe-16.04'
       subnets:
-# TODO: parametrize address root (192.168.11), fabric-2, dhcp start/end?
+        # TODO: parametrize address root (192.168.11), dhcp start/end?
         192.168.11.0/24:
-          fabric: fabric-2
           cidr: 192.168.11.0/24
           gateway_ip: ${_param:single_address}
           iprange:
             start: 192.168.11.5
             end: 192.168.11.250
             type: dynamic
+          vlans:
+            untagged:
+              vid: 0
+              dhcp_on: true
+              primary_rack: ${_param:infra_maas_node01_hostname}
       machines:
         kvm01:
           interface: