Add custom interfaces file and update docs for PowerVM RMC

This patch adds templating a custom Nova interfaces file for PowerVM only
to support doing mixed IPV4-only and IPV6-only deployments. It also adds
documentation for configuration of PowerVM RMC.

Change-Id: Ib1ff51c95998bbc3183ea9b896dc8fa2dfbc0435
Closes-Bug: #1643988

doc/source/app-powervm.rst

@@ -96,3 +96,17 @@ Additionally, you can enable flat network injection by using the
     nova_nova_conf_overrides:
       DEFAULT:
         flat_injected: True
+
+Enabling PowerVM RMC
+~~~~~~~~~~~~~~~~~~~~
+
+To enable PowerVM RMC_, IPv4/IPv6 dual-stack mode must be enabled. To do this,
+you must set ``use_ipv6`` using the ``nova_nova_conf_overrides`` variable:
+
+.. code-block:: yaml
+
+    nova_nova_conf_overrides:
+      DEFAULT:
+        use_ipv6: True
+
+.. _RMC: http://www.ibm.com/support/knowledgecenter/8284-22A/p8eig/p8eig_rmc.htm

releasenotes/notes/support-powervm-rmc-dedce9da5fdd1bea.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - Setup for the PowerVM driver was not properly configuring the system
+    to support RMC configuration for client instances. This fix introduces
+    an interface template for PowerVM that properly supports mixed IPV4/IPV6
+    deploys and adds documentation for PowerVM RMC. For more information see
+    bug 1643988.

tasks/nova_compute_powervm.yml

@@ -28,3 +28,13 @@
   changed_when: false
   tags:
     - nova-powervm
+
+- name: Template Nova interfaces file
+  template:
+    src: nova-interfaces-template.j2
+    dest: /etc/nova/nova-interfaces-template
+    owner: "root"
+    group: "root"
+    mode: 0644
+  tags:
+    - nova-powervm

templates/nova-interfaces-template.j2

@@ -0,0 +1,51 @@
+# {{ ansible_managed }}
+
+{% raw %}
+# Injected by Nova on instance boot
+#
+# This file describes the network interfaces available on your system
+# and how to activate them. For more information, see interfaces(5).
+
+# The loopback network interface
+auto lo
+iface lo inet loopback
+{% for ifc in interfaces %}
+
+auto {{ ifc.name }}
+{% if ifc.address %}
+iface {{ ifc.name }} inet static
+    hwaddress ether {{ ifc.hwaddress }}
+    address {{ ifc.address }}
+    netmask {{ ifc.netmask }}
+    broadcast {{ ifc.broadcast }}
+{% if ifc.gateway %}
+    gateway {{ ifc.gateway }}
+{% endif %}
+{% if ifc.dns %}
+    dns-nameservers {{ ifc.dns }}
+{% endif %}
+{% endif %}
+{% if use_ipv6 %}
+{% if ifc.address_v6 %}
+{% if libvirt_virt_type == 'lxc' %}
+iface {{ ifc.name }} inet6 manual
+    post-up ip -6 addr add {{ ifc.address_v6 }}/{{ifc.netmask_v6 }} dev ${IFACE}
+{% if ifc.gateway_v6 %}
+    post-up ip -6 route add default via {{ ifc.gateway_v6 }} dev ${IFACE}
+{% endif %}
+{% else %}
+iface {{ ifc.name }} inet6 static
+    hwaddress ether {{ ifc.hwaddress }}
+    address {{ ifc.address_v6 }}
+    netmask {{ ifc.netmask_v6 }}
+{% if ifc.gateway_v6 %}
+    gateway {{ ifc.gateway_v6 }}
+{% endif %}
+{% if ifc.dns_v6 %}
+    dns-nameservers {{ ifc.dns_v6 }}
+{% endif %}
+{% endif %}
+{% endif %}
+{% endif %}
+{% endfor %}
+{% endraw %}

templates/nova.conf.j2

@@ -113,6 +113,10 @@ vif_plugging_is_fatal = False
 # Hypervisor
 default_ephemeral_format = ext4
 
+{% if nova_virt_type == 'powervm' %}
+injected_network_template = /etc/nova/nova-interfaces-template
+{% endif %}
+
 # Configdrive
 force_config_drive = {{ nova_force_config_drive }}