Excerpts from Jim Rollenhagen's message of 2016-01-08 09:56:46 -0800: > On Fri, Jan 08, 2016 at 11:00:35AM +0100, Thierry Carrez wrote: > > Jim Rollenhagen wrote: > > >[...] > > >Here's the catch - mimic is built on twisted. I know twisted was > > >previously removed from OpenStack (or at least people said "pls no", I > > >don't know the full history). We didn't intend to stealth-introduce > > >twisted back into g-r, but it was pointed out to me that it may appear > > >this way, so here I am letting everyone know. lifeless pointed out that > > >when tests are failing, people may end up digging into mimic or twisted > > >code, which most people in this community aren't familiar with AFAIK, > > >which is a valid point though I hope it isn't required often. > > > > A bit of history with Twisted. > > > > Back in 2010 we decided we could not afford asking OpenStack developers to > > be familiar with multiple service architecture frameworks, and eventlet was > > chosen as the simplest framework to learn and debug. The best reference I > > found on this is still visible in the wiki: > > > > https://wiki.openstack.org/wiki/UnifiedServiceArchitecture > > > > >So, the primary question here is: do folks have a problem with adding > > >twisted here? We're holding off on Ironic changes that depend on this > > >until this discussion has happened, but aren't reverting the g-r change > > >until we decide one way or another. > > > > The only friction I see is how many developers would be expected to need to > > learn Twisted in order to complete their jobs. My understanding is that > > Twisted expertise could be needed to debug python-ironicclient functional > > tests, which makes the cost relatively limited. So if Mimic brings in a > > clear and significant benefit, I don't think its Twisted dependence should > > play that much against it. > > > > However, I agree with Sean and Jay that the benefit is unclear -- the few > > features that Mimic brings seem to be outweighed by the increased risk of > > introducing a delta between the implementation and the mock. If the main > > benefit is that it's used in other Rackspace projects for testing (like Ben > > said), I'm not sure that makes a compelling argument for the rest of the > > community... > > No, that is not the main benefit, at all. Ben isn't involved in Ironic > and until now has had nothing to do with this work to add mimic here, so > I'm not sure where he got that impression from, or why he's speaking on > our behalf as to the goals here. > > As pointed out before, the risk of a delta between the mocks in mimic > and reality is identical to the risk of a delta between the mocks in a > client's unit tests and reality, so I don't see a particular downside > there. > > Again, I think "benefit is unclear" isn't a valid reason to block this, > so unless someone posts a revert we're going to move forward with this.
I have not made a decision myself about whether it's right to go ahead or not, but if we need to have a revert in place to continue the conversation, I'll do that. Please see https://review.openstack.org/#/c/265416/ as the patch to revert adding mimic. Doug __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: [email protected]?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
