Ensure veths are only 15 characters long

A veth pair on a linux system can only have 15 characters in
its name. This PR ensures that the built veth pair is templated
and string spliced such that it can ONLY be a maximum of 15
characters long.

Change-Id: Ibe78679b9364b41cb68ec42599a906b3f1552e41
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

defaults/main.yml

@@ -102,3 +102,5 @@ lxc_container_download_template_options: >
 
 # Toggle the restart of containers via the handler.
 lxc_container_allow_restarts: yes
+
+lxc_container_network_veth_pair: "{{ inventory_hostname[-8:].replace('-', '').replace('_', '') }}_{{ item.value.interface }}"

tasks/container_create.yml

@@ -250,7 +250,7 @@
   shell: >
     /usr/local/bin/lxc-veth-wiring
     "{{ inventory_hostname }}"
-    "{{ inventory_hostname[-8:].replace('-', '').replace('_', '') }}_{{ item.value.interface }}"
+    "{{ lxc_container_network_veth_pair[-15:] }}"
     "{{ item.value.interface }}"
     "{{ item.value.bridge }}"
   register: wiring_script

templates/container-interface.ini.j2

@@ -8,7 +8,7 @@ lxc.network.name = {{ item.value.interface }}
 # Name the veth after the container
 # NOTE(major): The lxc.network.veth.pair line must appear right after
 # lxc.network.name or it will be ignored.
-lxc.network.veth.pair = {{ inventory_hostname[-8:].replace('-', '').replace('_', '') }}_{{ item.value.interface }}
+lxc.network.veth.pair = {{ lxc_container_network_veth_pair[-15:] }}
 {% endif %}
 # Host link to attach to, this should be a bridge if lxc.network.type = veth
 lxc.network.link = {{ item.value.bridge }}