k3s/pkg/cloudprovider
Kubernetes Submit Queue 3adb9b428b Merge pull request #46660 from jackfrancis/azure-cloudprovider-backoff
Automatic merge from submit-queue (batch tested with PRs 43005, 46660, 46385, 46991, 47103)

Azure cloudprovider retry using flowcontrol

An initial attempt at engaging exponential backoff for API error responses.

Addresses #47048

Uses k8s.io/client-go/util/flowcontrol; implementation inspired by GCE
cloudprovider backoff.



**What this PR does / why we need it**:

The existing azure cloudprovider implementation has no guard rails in place to adapt to unexpected underlying operational conditions (i.e., clogs in resource plumbing between k8s runtime and the cloud API). The purpose of these changes is to support exponential backoff wrapping around API calls; and to support targeted rate limiting. Both of these options are configurable via `--cloud-config`.

Implementation inspired by the GCE's use of `k8s.io/client-go/util/flowcontrol` and `k8s.io/apimachinery/pkg/util/wait`, this PR likewise uses `flowcontrol` for rate limiting; and `wait` to thinly wrap backoff retry attempts to the API.

**Special notes for your reviewer**:


Pay especial note to the declaration of retry-able conditions from an unsuccessful HTTP request:
- all `4xx` and `5xx` HTTP responses
- non-nil error responses

And the declaration of retry success conditions:
- `2xx` HTTP responses

Tests updated to include additions to `Config`.

Those may be incomplete, or in other ways non-representative.

**Release note**:

```release-note
Added exponential backoff to Azure cloudprovider
```
2017-06-07 13:30:58 -07:00
..
providers Merge pull request #46660 from jackfrancis/azure-cloudprovider-backoff 2017-06-07 13:30:58 -07:00
BUILD Initialize cloud providers with a K8s clientBuilder 2017-05-17 14:38:25 -07:00
OWNERS Updated top level owners file to match new format 2017-01-19 11:29:16 -08:00
README.md Update docs/ URLs to point to proper locations 2017-06-05 22:13:54 -07:00
cloud.go Watching ClusterId from within GCE cloud provider 2017-05-23 14:11:24 -07:00
doc.go
plugins.go add external cloudprovider to clerly denote the offloading off cloudprovider tasks 2017-03-06 10:45:13 -08:00

README.md

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.