Document when pre-release upgrade scripts are run

Every time I have to figure out where in the sequence
of upgrade events the per-release within-$base and
from-$base scripts run, I have to dig into the doc.

We have a pretty good document already on the sequence
of phases in a grenade run, but the upgrade section is
pretty fuzzy, and with no mention of when the per-release
scripts run relative to when new code is installed, which
is pretty important if you're going to write one of these
scripts.

So this adds some docs related to when those per-release
upgrade scripts happen relative to installing new code
during the upgrade.

Change-Id: Ic79cd10b2df5fa54a13f73cf49c8f73fa93e9381
This commit is contained in:
Matt Riedemann 2018-09-06 16:30:31 -04:00
parent 7bd91280e2
commit 603ac2202e
2 changed files with 20 additions and 0 deletions

View File

@ -138,6 +138,24 @@ While create / destroy are only going to be called once in the current
interface, bonus points for also making those idempotent for interface, bonus points for also making those idempotent for
resiliancy in testing. resiliancy in testing.
**Per-release upgrade scripts**
There are times when :ref:`exceptional <upgrade-exceptions>` manual upgrade
steps must be performed to get from one release to the next, or even within
the same release. Grenade supports this with per-release scripts found in
each project, e.g.::
projects/
60_nova/
from-ocata/
upgrade-nova
Regarding the sequence of when these per-release scripts are called, any
``within-$base`` script should be run *before* installing new code, and any
``from-$base`` script should be run *after* installing new code but before
starting the services with the new code. This is because configuration or
database changes may be needed before the upgraded code is started.
Supporting Methods Supporting Methods
------------------ ------------------

View File

@ -51,6 +51,8 @@ Grenade works under the following theory of upgrade.
the entire upgrade (whether or not Nova services are up). Taking down the entire upgrade (whether or not Nova services are up). Taking down
the control plane should not take down your VMs. the control plane should not take down your VMs.
.. _upgrade-exceptions:
- Any other required changes on upgrade are an **exception** and must be - Any other required changes on upgrade are an **exception** and must be
called out in the release notes. called out in the release notes.