Reuse instance-groups for internal load balancers #313
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
k8s-ci-robot
added
kind/bug
Fedosin
force-pushed
the
internal_lb
branch
4 times, most recently
from
e556732
to
9f6ed06
Compare
k8s-ci-robot
added
size/XXL
Based on docs for internal loadbalancer here [1], backend services [2] and instances in instance-groups [3], following restrictions apply: - Internal LB can load balance to VMs in same region, but different subnets - Instance groups for the backend service must contain instance of the same subnet - An instance can only belong to one load balanced instance group - It is probably useful use-case to have nodes for the cluster belong to more than one subnet. And the current setup fails to create an internal load balancer with nodes in multiple subnets. This change finds pre-existing instance-groups that ONLY contain instances that belong to the cluster, uses them for the backend service. And only ensures instance-groups for remaining ones. [1] https://cloud.google.com/load-balancing/docs/internal [2] https://cloud.google.com/load-balancing/docs/backend-service#restrictions_and_guidance [3] https://cloud.google.com/compute/docs/instance-groups/creating-groups-of-unmanaged-instances#addinstances Co-authored-by: Abhinav Dahiya <abhinav.dahiya@redhat.com>
k8s-ci-robot
added
size/L
|
[APPROVALNOTIFIER] This PR is NOT APPROVED This pull-request has been approved by: Fedosin The full list of commands accepted by this bot can be found here.
Needs approval from an approver in each of these files:
Approvers can indicate their approval by writing |
|
@Fedosin Is it still needed? If yes, could you reopen? |
|
@Fedosin I believe this bug is still relevant? Can we get it reopened please? |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
What type of PR is this?
/kind bug
What this PR does / why we need it:
Based on docs for internal loadbalancer here 1, backend services 2 and instances in instance-groups 3, following restrictions apply,
Also the use-case that some of these nodes (machines) might be part of some internal load balancer that is not managed by k8s is also pretty valid.
for example, you might have the machines hosting the control-plane (kube-apiserver) want to be part of a separate ILB that provides access to the apiserver through LB not managed by the k8s Service type Load Balancer.
But the current setup fails to create an interal load balancer like
So the subnet limitation should be automatically handled by the k8s cloud provider, but for now allowing users to create the IGs for instances that require this special setup should definietly help, and k8s cloud provider can just use those as-is, while maintaining the membership and lifecycle for ones created by it.
This change finds pre-existing instance-groups that ONLY contain instances that belong to the cluster, uses them for the backend service. And only ensures instance-groups for remaining ones.
Does this PR introduce a user-facing change?:
Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:
The work is based on kubernetes/kubernetes#84466