Updates for Trusty VMs

Currently, attempting to use Trusty (14.04) VMs causes VMs to not
provision correctly due to a grub-install error.  With respect to this
specific issue, this commit updates vm.preseed.j2 by removing some
grub-installer options which were not present before the ansible
rewrite.

Secondly, with that change in place, VMs do not come online on their
10.0.236 addresses as something is overwriting
/etc/networking/interfaces, which wipes out the source of the
/etc/network/interfaces.d directory.  Bug [1] seems to indicate this
is in fact an issue and has been resolved, however attempts at using
this preseed option (netcfg/target_network_config) were not successful.
As a workaround, we simply chattr +i the interfaces file in
vm-post-install-script.sh.j2, and then remove the attr in
deploy-vms.yml when the instance is up an accessible.

[1] https://bugs.launchpad.net/ubuntu/+source/netcfg/+bug/1361902

Change-Id: I12d0c5108d1df0ab02b69d1b8cdb271a02999602

multi-node-aio/playbooks/deploy-vms.yml

@@ -138,6 +138,20 @@
         - src: "{{ lookup('env', 'HOME') }}/.ssh/id_rsa.pub"
           dest: /root/.ssh/id_rsa.pub
 
+# In vm-post-install-script.sh.j2 we chattr +i the interfaces file to prevent
+# the preseed system from overwriting the file after we've modified it.  The
+# task below simply removes the immutable attribute.
+- name: Remove immutable attr from /etc/network/interfaces
+  hosts: vm_servers
+  gather_facts: true
+  tasks:
+    - file:
+        path: /etc/network/interfaces
+        attr: ""
+      when:
+        - ansible_distribution | lower == "ubuntu"
+        - ansible_distribution_release | lower == "trusty"
+
   environment: "{{ deployment_environment_variables | default({}) }}"
 
   tags:

multi-node-aio/playbooks/pxe/debian/vm-post-install-script.sh.j2

@@ -13,6 +13,11 @@ echo "{{ tftp_ssh_key }}" >> /root/.ssh/authorized_keys
 
 wget --no-proxy http://{{ tftp_server }}/networking/$(cat /etc/hostname)-bridges.cfg -O /etc/network/interfaces.d/vm-bridges.cfg
 wget --no-proxy http://{{ tftp_server }}/networking/basic-debian-interface.cfg -O /etc/network/interfaces
+# Trusty VMs seem to have their interfaces file overwritten after we write to
+# it, so we make it immutable to ensure no further changes take place
+# NOTE: We remove the immutable attr in deploy-vms.yml once the instance is up
+#       and accessible.
+[[ "$(lsb_release -sc)" == "trusty" ]] && chattr +i /etc/network/interfaces
 
 cat > /etc/network/if-up.d/post-up-rules <<EOF
 #!/usr/bin/env bash

multi-node-aio/playbooks/pxe/debian/vm.preseed.j2

@@ -215,8 +215,6 @@ d-i passwd/root-password-again password secrete
 # This is fairly safe to set, it makes grub install automatically to the MBR
 # if no other operating system is detected on the machine.
 d-i grub-installer/only_debian boolean true
-d-i grub-installer/with_other_os boolean true
-d-i grub-installer/bootdev string default
 
 # Post Install