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, 26 insertions, 0 deletions

diff --git a/mcp/patches/0007-linux.network.interface-noifupdown-support.patch b/mcp/patches/0007-linux.network.interface-noifupdown-support.patch
new file mode 100644
index 000000000..5d9ce7be5
--- /dev/null
+++ b/mcp/patches/0007-linux.network.interface-noifupdown-support.patch
@@ -0,0 +1,26 @@
+From: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
+Date: Sat, 5 Aug 2017 02:03:01 +0200
+Subject: [PATCH] linux.network.interface: noifupdown support
+
+According to [1], salt states/network supports "noifupdown" as a
+parameter for each interface.
+Adjust salt formula part for `linux.network.interface`, by extending
+the "interface_params" in <linux/map.jinja> accordingly.
+
+Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
+Signed-off-by: Charalampos Kominos <Charalampos.Kominos@enea.com>
+Signed-off-by: Guillermo Herrero <Guillermo.Herrero@enea.com>
+---
+
+diff --git a/linux/map.jinja b/linux/map.jinja
+index d3227ca..8a2243d 100644
+--- a/linux/map.jinja
++++ b/linux/map.jinja
+@@ -92,6 +92,7 @@
+     'updelay',
+     'hashing-algorithm',
+     'hardware-dma-ring-rx',
++    'noifupdown',
+ ] %}
+
+ {% set network = salt['grains.filter_by']({