- Sidecar termination is now serialized and each sidecar container will receive a `SIGTERM` after all main containers and later starting sidecar containers have terminated. ([#120620](https://github.com/kubernetes/kubernetes/pull/120620), [@tzneal](https://github.com/tzneal))

- The CSI driver-registrar external sidecar container v1.0.0-rc2 is known to take up to 1 minute to start in some cases. We expect this issue to be resolved in a future release of the sidecar container. For verification, please see the release notes of future releases of the external sidecar container. ([#76](https://github.com/kubernetes-csi/driver-registrar/issues/76))

- The new feature gate "SidecarContainers" is now available. This feature introduces sidecar containers, a new type of init container that starts before other containers but remains running for the full duration of the pod's lifecycle and will not block pod termination. ([#116429](https://github.com/kubernetes/kubernetes/pull/116429), [@...

- kubeadm: remove misleading error message regarding image pulling ([#66658](https://github.com/kubernetes/kubernetes/pull/66658), [@dixudx](https://github.com/dixudx))
- kubeadm: Pull sidecar and dnsmasq-nanny images when using kube-dns ([#66499](https://github.com/kubernetes/kubernetes/pull/66499), [@rosti](https://github.com/rosti))

- Revised node selection based on container image location. The kube-scheduler now considers whether nodes have the required images available for init containers, and for sidecar containers if the cluster has 'SidecarContainers' enabled. ([#123366](https://github.com/kubernetes/kubernetes/pull/123366), [@kerthcet](https://github.com/kerthcet))

- The sidecar finish time will be accounted when calculating the job's finish time. ([#124942](https://github.com/kubernetes/kubernetes/pull/124942), [@AxeZhan](https://github.com/AxeZhan)) [SIG Apps]

* Reduced the CPU and memory requests for the Metrics Server Nanny sidecar container to free up unused resources.  ([#57252](https://github.com/kubernetes/kubernetes/pull/57252), [@kawych](https://github.com/kawych))

* GCE: Fixes loadbalancer creation and deletion issues appearing in 1.10.5. ([#66400](https://github.com/kubernetes/kubernetes/pull/66400), [@nicksardo](https://github.com/nicksardo))
* kubeadm: Pull sidecar and dnsmasq-nanny images when using kube-dns ([#66499](https://github.com/kubernetes/kubernetes/pull/66499), [@rosti](https://github.com/rosti))