On 5/23/14, 3:07 PM, Paul Michali (pcm) wrote:
Thanks for the comments Gary!
Typically, the device driver (backend) and service driver, for a
provider won't have any database requirements (at least for VPN). For
the Cisco VPN, the service driver has one additional table that it
maintains for mapping, but even in that case, there is no modification
to the built in tables for the VPN plugin.
If these sorts of additional tables might use foreign keys, cascaded
deletes, etc., it probably make sense to go with the precommit approach
to make these explicitly part of the transactions.
-Bob
So, the action is validation, persist, apply, with the validation
possibly having a provider override/extend, the apply always having a
provider action, and the persistence always being the "core"
persistence. It's a question of being validate, persist/commit,
apply, or pre-commit, commit/persist, post-commit, for naming.
Regards,
PCM (Paul Michali)
MAIL ......... [email protected] <mailto:[email protected]>
IRC ........... pcm_ (irc.freenode.com <http://irc.freenode.com>)
TW ............ @pmichali
GPG Key ... 4525ECC253E31A83
Fingerprint .. 307A 96BB 1A4C D2C7 931D 8D2D 4525 ECC2 53E3 1A83
On May 23, 2014, at 12:40 PM, Gary Duan <[email protected]
<mailto:[email protected]>> wrote:
Hi, Paul,
If the backend driver maintains its own database, I think the
pre_commit and post_commit approach has an advantage. The typical
code flow is able to keep the driver and plugin database consistent.
Regarding question 1, where validation methods should be added, I am
leaning towards A, but I also agree validation hooks can be added
later when they are needed. It's more important to get provider and
flavor logic officially supported for services.
Thanks,
Gary
On Fri, May 23, 2014 at 7:24 AM, Paul Michali (pcm) <[email protected]
<mailto:[email protected]>> wrote:
Hi,
I'm working on a task for a BP to separate validation from
persistence logic in L3 services code (VPN currently), so that
providers can override/extend the validation logic (before
persistence).
So I've separated the code for one of the create APIs, placed the
default validation into an ABC class (as a non-abstract method)
that the service drivers inherit from, and modified the plugin to
invoke the validation function in the service driver, before
doing the persistence step.
The flow goes like this...
def create_vpnservice(self, context, vpnservice):
driver = self._get_driver_for_vpnservice(vpnservice)
*driver.validate_create_vpnservice(context, vpnservice)*
super(VPNDriverPlugin, self).create_vpnservice(context,
vpnservice)
driver.apply_create_vpnservice(context, vpnservice)
If the service driver has a validation routine, it'll be invoked,
otherwise, the default method in the ABC for the service driver
will be called and will handle the "baseline" validation. I also
renamed the service driver method that is used for applying the
changes to the device driver as apply_* instead of using the same
name as is used for persistence (e.g. create_vpnservice ->
apply_create_vpnservice).
The questions I have is...
1) Should I create new validation methods A) for every create
(and update?) API (regardless of whether they currently have any
validation logic, B) for resources that have some validation
logic already, or C) only for resources where there are providers
with different validation needs? I was thinking (B), but would
like to hear peoples' thoughts.
2) I've added validation_* and modified the other service driver
call to apply_*. Should I instead, use the ML2 terminology of pre
commit_* and post commit_*? I personally favor the former, as it
is more descriptive of what is happening in the methods, but I
understand the desire for consistency with other code.
3) Should I create validation methods for code, where defaults
are being set for missing (optional) information? For example,
VPN IKE Policy lifetime being set to units=seconds, value=3600,
if not set. Currently, provider implementations have same
defaults, but *could* potentially use different defaults. The
alternative is to leave this in the persistence code and not
allow it to be changed. This could be deferred, if 1C is chosen
above.
Looking forward to your thoughts...
Thanks!
PCM (Paul Michali)
MAIL ......... [email protected] <mailto:[email protected]>
IRC ........... pcm_ (irc.freenode.com <http://irc.freenode.com/>)
TW ............ @pmichali
GPG Key ... 4525ECC253E31A83
Fingerprint .. 307A 96BB 1A4C D2C7 931D 8D2D 4525 ECC2 53E3 1A83
_______________________________________________
OpenStack-dev mailing list
[email protected]
<mailto:[email protected]>
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
_______________________________________________
OpenStack-dev mailing list
[email protected]
<mailto:[email protected]>
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
_______________________________________________
OpenStack-dev mailing list
[email protected]
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
_______________________________________________
OpenStack-dev mailing list
[email protected]
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
