Used named veth pairs that match container

The default veth names from LXC make it difficult to tell which veth
corresponds to each container.  This patch sets a unique veth name
that matches the container as well as the network device inside the
container.  It should make troubleshooting a little easier.

Oddly enough, this patch seems to fix or greatly reduce the occurence
of the issues seen in ticket 1491440.

Partial-Bug: 1491440
Implements: blueprint named-veths
Change-Id: I28553fd1b4f36991e11d55d56c3f0f46af9e52be

playbooks/roles/lxc_container_create/tasks/container_create.yml

@@ -187,6 +187,19 @@
   tags:
     - lxc-container-networks
 
+# NOTE(major): the lxc.network.veth.pair line must appear *immediately* after
+# the lxc.network.name congfiguration line or it will be ignored.  That's why
+# you'll find a "insertafter" in this YAML block.
+- name: Add veth pair name to match container name
+  lineinfile:
+    dest: "/var/lib/lxc/{{ inventory_hostname }}/config"
+    line: "lxc.network.veth.pair = {{ inventory_hostname[-8:].replace('-', '').replace('_', '') }}_eth0"
+    insertafter: "^lxc.network.name"
+    backup: "true"
+  delegate_to: "{{ physical_host }}"
+  tags:
+    - lxc-container-networks
+
 - name: Container network includes
   lineinfile:
     dest: "/var/lib/lxc/{{ inventory_hostname }}/config"

playbooks/roles/lxc_container_create/templates/container-interface.ini.j2

@@ -4,6 +4,10 @@
 lxc.network.type = {{ item.value.type|default('veth') }}
 # Network device within the container
 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 }}
 # Host link to attach to, this should be a bridge
 lxc.network.link = {{ item.value.bridge }}
 # Hardware Address
@@ -12,4 +16,3 @@ lxc.network.hwaddr = 00:16:3e:xx:xx:xx
 lxc.network.flags = up
 # Set the container network MTU
 lxc.network.mtu = {{ item.value.mtu|default('1500') }}
-