AWS: Remove blackhole routes in our managed range

[justinsb]

Blackhole routes otherwise acccumulate unboundedly. We also are careful
to ensure that we do so only within the managed range, which requires
enlisting the help of the routecontroller.

Fix #47524

AWS: clean up blackhole routes when using kubenet

[justinsb]

So I think this is relatively low risk (because it is gated behind the blackhole boolean so it should be aws only). The issue is problematic for bigger users - multiple users have independently come up with their own workarounds.

Assuming this merges, I will then immediately propose it for backport to the 1.6 branch, and the 1.7 branch if needed. Given that, @dchen1107 do you think we should put this into 1.7?

[justinsb]

ping @stts / @vishh for review

For approve:
/assign @wojtek-t

[dchen1107]

/approve

[dchen1107]

@justinsb I approved this pr for 1.7, and left @wojtek-t for review. If @wojtek-t cannot review this, who should be the reviewer for this?

[chrislovecnm]

@dchen1107 looking at it now

/assign chrislovecnm

[chrislovecnm]

Looks good

[chrislovecnm]

/assign @chrislovecnm

[chrislovecnm]

/lgtm

[k8s-github-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: chrislovecnm, dchen1107, justinsb

Associated issue: 47524

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these OWNERS Files:

• pkg/cloudprovider/OWNERS [dchen1107]
• pkg/controller/route/OWNERS [dchen1107]

You can indicate your approval by writing /approve in a comment
You can cancel your approval by writing /approve cancel in a comment

[chrislovecnm]

/test pull-kubernetes-kubemark-e2e-gce

[k8s-github-robot]

Automatic merge from submit-queue