Adding a fixed_ip to an instance with neutron only updates the first port using the first subnet
Bug #1430512 reported by
Matt Riedemann
This bug affects 1 person
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
OpenStack Compute (nova) |
Won't Fix
|
Low
|
Gary Kotton |
Bug Description
This blueprint added support to nova for having multiple ports attached to an instance on the same network:
https:/
However, with the "Multinic" API extension in nova, if you're adding a fixed_ip to an instance, the neutronv2 API will only copy the fixed_ips from the first subnet on the network to the first port associated with the instance:
https:/
Once that's done, the code returns and the other subnets/ports aren't handled.
summary: |
Adding a fixed_ip to an instance with neutron only updates the first - port + port using the first subnet |
Changed in nova: | |
milestone: | kilo-3 → kilo-rc1 |
Changed in nova: | |
assignee: | Gary Kotton (garyk) → nobody |
status: | In Progress → Confirmed |
Changed in nova: | |
assignee: | nobody → Gary Kotton (garyk) |
status: | Confirmed → In Progress |
Changed in nova: | |
status: | In Progress → Won't Fix |
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OK, so up front that multinic plugin is horrible - it's really intended for nova-network with multiple networks and an explicit interface for every network in the system. It's also short on documentation: I can't find mention on http:// developer. openstack. org/api- ref-compute- v2-ext. html and http:// docs.openstack. org/developer/ nova/devref/ multinic. html is one of a number of examples of documentation with a complete emphasis on nova-network configurations and no mention of fixed IPs. I didn't find any documentation that it worked with Neutron at all, though the code is present and it clearly does make the attempt (though in reality it's a wrapper around neutron port-update, and, I suspect, not a very good one if you happen to be using multiple subnets).
I think we have two options:
1. rewrite add-fixed-ip to add a new address to every port (question: what happens when we run out of addresses? Hard to unwind the partial work done...)
2. rewrite add-fixed-ip it to not work when multiple interfaces share a subnet (noting that (a) it's not intended for this use case and (b) neutron port-update is available as a much more flexible and precise alternative)
I don't think doing (2) is unfair. It's never worked in this case before, because multiple NICs on one network was never previously possible. It doesn't exclude behaviour because other APIs are available. And it doesn't change nova-network behaviour where multiple NICs on one network still aren't possible.
Also, I'm not sure that adding additional fixed IPs to multiple NICs makes any more sense in the context of the API call (seems unlikely this is what the tenant would want or expect).