Unify container network interfaces using Systemd Networkd for ubuntu,
centos, and openSUSE. This change allows the role to use a single way to
configure container networks.
Care has been taken to ensure we're able to cleanly upgrade to the new
capabilities within existing environments without breaking any feature
compatibility or causing any container restarts.
It's also worth noting that all of the pre/post networking up/down
script options have been converted to systemd "oneshot" services. This
retains the ability to run adhoc scripts post network availability
while also opening up this capability, which used to be ubuntu only,
to all of our supported operating systems.
> Our usage of `lxc-attach` was removed in favor of `nsenter` to fix a
issue where multiple `lxc-attach` commands issued to a single physical
host could result in a hang.
> Scripts that were being generated inline have been placed into
template files. This solves a long standing memory consumption issue
when creating lots of containers. The old shell tasks will now be
executed from a generated script. While this should also help with
debugging, the main driver is to ensure better system stability.
> A lot of cleanup has been done throughout the task files and
templates. In the process of updating the role to use unified
networking a lot of duplicate tasks, scripts, and processes have
consolidated.
> Handlers have been added for network connection wait conditions and
to various service restarts.
> The OSA plugins have been added to this role as a dependency. We
rely on the connection plugins throughout the stack however we were
doing a lot of workarounds to cater to the possibility of a deployer
running this role without them. This change simply adds the plugins
as a known dependency which allows for a more streamlined setup.
Change-Id: I5d3ddcfa11d575648a69a04f2fb30236c2c89da3
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>
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