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Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. openstack: remove orphaned routes from terminated instances **What this PR does / why we need it**: At the moment the openstack cloudprovider only returns routes where the `NextHop` address points to an existing openstack instance. This is a problem when an instance is terminated before the corresponding node is removed from k8s. The existing route is not returned by the cloudprovider anymore and therefore never considered for deletion by the route controller. When the route's `DestinationCIDR` is reassigned to a new node the router ends up with two routes pointing to a different `NextHop` leading to broken networking. This PR removes skipping routes pointing to unknown next hops when listing routes. This should cause [this conditional](93dc3763b0/pkg/controller/route/route_controller.go (L208)) in the route controller to succeed and have the route removed if the route controller [feels responsible](93dc3763b0/pkg/controller/route/route_controller.go (L206)). ```release-note OpenStack cloudprovider: Ensure orphaned routes are removed. ```
Deprecation Notice: This directory has entered maintenance mode and will not be accepting new providers. Cloud Providers in this directory will continue to be actively developed or maintained and supported at their current level of support as a longer-term solution evolves.
Overview:
The mechanism for supporting cloud providers is currently in transition: the original method of implementing cloud provider-specific functionality within the main kubernetes tree (here) is no longer advised; however, the proposed solution is still in development.
Guidance for potential cloud providers:
- Support for cloud providers is currently in a state of flux. Background information on motivation and the proposal for improving is in the github proposal.
- In support of this plan, a new cloud-controller-manager binary was added in 1.6. This was the first of several steps (see the proposal for more information).
- Attempts to contribute new cloud providers or (to a lesser extent) persistent volumes to the core repo will likely meet with some pushback from reviewers/approvers.
- It is understood that this is an unfortunate situation in which 'the old way is no longer supported but the new way is not ready yet', but the initial path is unsustainable, and contributors are encouraged to participate in the implementation of the proposed long-term solution, as there is risk that PRs for new cloud providers here will not be approved.
- Though the fully productized support envisioned in the proposal is still 2 - 3 releases out, the foundational work is underway, and a motivated cloud provider could accomplish the work in a forward-looking way. Contributors are encouraged to assist with the implementation of the design outlined in the proposal.
Some additional context on status / direction:
- 1.6 added a new cloud-controller-manager binary that may be used for testing the new out-of-core cloudprovider flow.
- Setting cloud-provider=external allows for creation of a separate controller-manager binary
- 1.7 adds extensible admission control, further enabling topology customization.