*   It is now possible to set multiple manifest URL headers with the kubelet's `--manifest-url-header` flag. Multiple headers for the same key will be added in the order provided. The ManifestURLHeader field in KubeletConfiguration object (kubeletconfig/v1alpha1) is now a map[string][]string, which facilitates writing JSON...

### SIG Multi-cluster (formerly known as SIG Federation)

[SIG Multi-cluster][] is responsible for infrastructure that supports
the efficient and reliable management of multiple Kubernetes clusters,
and applications that run in and across multiple clusters.

For the 1.8 release, SIG Multicluster focussed on expanding the set of
Kubernetes primitives that our Cluster Federation control plane

- Changed the error message to `cannot exec into multiple objects at a time` when file passed to `kubectl exec` contains multiple resources ([#114249](https://github.com/kubernetes/kubernetes/pull/114249), [@ardaguclu](https://github.com/ardaguclu))

  
  Multi vCenter support is deprecated as of v1.21. If you have a Kubernetes cluster spanning across multiple vCenter servers, please consider moving all k8s nodes to a single vCenter Server. vSphere CSI Driver does not support Kubernetes deployment spanning across multiple vCenter servers.
  

* GCE: Fix to make the built-in `kubernetes` service properly point to the master's load balancer address in clusters that use multiple master VMs. ([#63696](https://github.com/kubernetes/kubernetes/pull/63696), [@grosskur](https://github.com/grosskur))

- Fixes high CPU usage in kubectl drain ([#95260](https://github.com/kubernetes/kubernetes/pull/95260), [@amandahla](https://github.com/amandahla)) [SIG CLI]
- Kube-apiserver: multiple comma-separated protocols in a single X-Stream-Protocol-Version header are now recognized, in addition to multiple headers, complying with RFC2616 ([#89857](https://github.com/kubernetes/kubernetes/pull/89857), [@tedyu](https://github.com/tedyu)) [SIG API Machinery]

- Kube-apiserver: multiple comma-separated protocols in a single X-Stream-Protocol-Version header are now recognized, in addition to multiple headers, complying with RFC2616 ([#89857](https://github.com/kubernetes/kubernetes/pull/89857), [@tedyu](https://github.com/tedyu)) [SIG API Machinery]

* Ensure the backend pools are set correctly for Azure SLB with multiple backend pools (e.g. outbound rules) ([#76691](https://github.com/kubernetes/kubernetes/pull/76691), [@feiskyer](https://github.com/feiskyer))

    * [fluentd-gcp addon] Bump prometheus-to-sd to v0.5.0 to pick up security fixes.
    * [metatada-proxy addon] Bump prometheus-to-sd v0.5.0 to pick up security fixes.
* Ensure the backend pools are set correctly for Azure SLB with multiple backend pools (e.g. outbound rules) ([#76691](https://github.com/kubernetes/kubernetes/pull/76691), [@feiskyer](https://github.com/feiskyer))

    * This keeps the behavior consistent with Docker integration, and fixes an issue that some container Prometheus metrics don't work when there are summary stats for multiple instances of the same pod.
* Kubelet: add usageNanoCores from CRI stats provider ([#73659](https://github.com/kubernetes/kubernetes/pull/73659), [@feiskyer](https://github.com/feiskyer))



# v1.13.6