EndpointSlices not used, even though configured. #14781
Description
What is the issue?
With enableEndpointSlices: true set in the linkerd-control-plane helm chart, the destination service still seems to be using the deprecated Endpoints API instead of the EndpointSlices API.
How can it be reproduced?
Install linkerd2 edge-25.11.1 on EKS 1.34 with enableEndpointSlices: true via helm chart. Observe warnings in linkerd-destination:
{"level":"info","msg":"Warning: v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice","time":"2025-12-04T18:50:28Z"}
Logs, error output, etc
{"level":"info","msg":"Warning: v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice","time":"2025-12-04T18:50:28Z"}
output of linkerd check -o short
---------------
‼ cli is up-to-date
is running version 25.11.1 but the latest edge version is 25.11.3
see https://linkerd.io/2/checks/#l5d-version-cli for hints
control-plane-version
---------------------
‼ control plane is up-to-date
is running version 25.11.1 but the latest edge version is 25.11.3
see https://linkerd.io/2/checks/#l5d-version-control for hints
linkerd-control-plane-proxy
---------------------------
‼ control plane proxies are up-to-date
some proxies are not running the current version:
* linkerd-destination-7cdf8bb84c-mvxfx (edge-25.11.1)
* linkerd-destination-7cdf8bb84c-q66fn (edge-25.11.1)
* linkerd-destination-7cdf8bb84c-rhq2l (edge-25.11.1)
* linkerd-identity-65b4c8c779-6zm7t (edge-25.11.1)
* linkerd-identity-65b4c8c779-b8dnt (edge-25.11.1)
* linkerd-identity-65b4c8c779-rpgsr (edge-25.11.1)
* linkerd-proxy-injector-555bc98d4-2bgtl (edge-25.11.1)
* linkerd-proxy-injector-555bc98d4-js6sf (edge-25.11.1)
* linkerd-proxy-injector-555bc98d4-phc7n (edge-25.11.1)
see https://linkerd.io/2/checks/#l5d-cp-proxy-version for hints
linkerd-viz
-----------
‼ viz extension proxies are up-to-date
some proxies are not running the current version:
* metrics-api-644877886b-4mx9r (edge-25.11.1)
* prometheus-8458c7cbd-bflkd (edge-25.11.1)
* tap-5ff7f778cf-2wsnn (edge-25.11.1)
* tap-5ff7f778cf-d7p84 (edge-25.11.1)
* tap-5ff7f778cf-xm7gd (edge-25.11.1)
* tap-injector-759ffb4bc4-hr296 (edge-25.11.1)
* web-65ff9bd49d-p8gvp (edge-25.11.1)
see https://linkerd.io/2/checks/#l5d-viz-proxy-cp-version for hints
Status check results are √
Environment
EKS 1.34
Linkerd2 edge-25.11.1
Amazon Linux 2023
Possible solution
No response
Additional context
No response
Would you like to work on fixing this bug?
None