On Fri, Feb 12, 2016, at 12:15 PM, Matt Riedemann wrote: > Forgive me for thinking out loud, but I'm trying to sort out how nova > would use a microversion in the nova API for the get-me-a-network > feature recently added to neutron [1] and planned to be leveraged in > nova (there isn't a spec yet for nova, I'm trying to sort this out for a > draft). > > Originally I was thinking that a network is required for nova boot, so > we'd simply check for a microversion and allow not specifying a network, > easy peasy. > > Turns out you can boot an instance in nova (with neutron as the network > backend) without a network. All you get is a measly debug log message in > the compute logs [2]. That's kind of useless though and seems silly. > > I haven't tested this out yet to confirm, but I suspect that if you > create a nova instance w/o a network, you can latter try to attach a > network using the os-attach-interfaces API as long as you either provide > a network ID *or* there is a public shared network or the tenant has a > network at that point (nova looks those up if a specific network ID > isn't provided). > > The high-level plan for get-me-a-network in nova was simply going to be > if the user tries to boot an instance and doesn't provide a network, and > there isn't a tenant network or public shared network to default to, > then nova would call neutron's new auto-allocated-topology API to get a > network. This, however, is a behavior change. > > So I guess the question now is how do we handle that behavior change in > the nova API? > > We could add an auto-create-net boolean to the boot server request which > would only be available in a microversion, then we could check that > boolean in the compute API when we're doing network validation. >
I think a flag like this is the right approach. If it's currently valid to boot an instance without a network than there needs to be something to distinguish a request that wants a network created vs. a request that doesn't want a network. This is still hugely useful if all that's required from a user is to indicate that they would like a network, they still don't need to understand/provide details of the network. > Today if you don't specify a network and don't have a network available, > then the validation in the API is basically just quota checking that you > can get at least one port in your tenant [3]. With a flag on a > microversion, we could also validate some other things about > auto-creating a network (if we know that's going to be the case once we > hit the compute). > > Anyway, this is mostly me getting thoughts out of my head before the > weekend so I don't forget it and am looking for other ideas here or > things I might be missing. > > [1] https://blueprints.launchpad.net/neutron/+spec/get-me-a-network > [2] > https://github.com/openstack/nova/blob/30ba0c5eb19a9c9628957ac8e617ae78c0c1fa84/nova/network/neutronv2/api.py#L594-L595 > [3] > https://github.com/openstack/nova/blob/30ba0c5eb19a9c9628957ac8e617ae78c0c1fa84/nova/network/neutronv2/api.py#L1107 > > -- > > Thanks, > > Matt Riedemann > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: > [email protected]?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: [email protected]?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
