Open Stack

As discussed during the "Launch Node, Ansible and Puppet" summit
session in Austin[1], we're making things unnecessarily hard on
ourselves by insisting on having multiple servers in our inventory
with the same name. In order to make server addition and replacement
automation simpler, lets start using an ordinal suffix on server
short names to differentiate them (we can still easily rely on DNS
for their non-numbered convenience names).

We do already have some servers with numbered suffixes but I don't
think this plan changes how we deal with them. When creating a new
server for a pool like that, just use the lowest available unused
number. Here's a relevant historical example:

    We have a 6-node Elasticsearch cluster, originally named
    es01 through es06. We needed to replace es01, so did an expand
    and contract adding es07 and then deleting es01 later. In the
    future let's say we need to replace es03, we can create es01 as
    its stand-in and then delete es03 leaving us with production
    servers es01, es02 and es04 through es07. This way replacing
    servers doesn't mean we grow our ordinal suffixes boundlessly.

I've proposed a minimal update[2] to our server creation documentation
indicating use of the new pattern everywhere. For some reason we've
been numbering servers starting from 01 and not 00, so as much as
I'm a fan of cardinal numbering I don't see any reason to switch now
(that train has already sailed).

[1] https://etherpad.openstack.org/p/newton-infra-launch-node-ansible-and-puppet
[2] https://review.openstack.org/320115
-- 
Jeremy Stanley