- Azure: check the nil error before invoke err.Error() ([#96623](https://github.com/kubernetes/kubernetes/pull/96623), [@nilo19](https://github.com/nilo19)) [SIG Cloud Provider]

  for background information.

### Scheduling

  - Opaque Integer Resources (OIRs) are deprecated and will be removed in
    version 1.9. Extended Resources (ERs) are a drop-in replacement for OIRs. You can use
    any domain name prefix outside of the `kubernetes.io/` domain instead of the
    `pod.alpha.kubernetes.io/opaque-int-resource-` prefix.

## Notable Features

- Failed to provision volume with StorageClass "azurefile-premium": failed to create share andy-mg1121-dynamic-pvc-1a7b2813-d1b7-11e8-9e96-000d3a03e16b in account f7228f99bcde411e8ba4900: failed to create file share, err: storage: service returned error: StatusCode=400, ErrorCode=InvalidHeaderValue, ErrorMessage=The value for one of the HTTP headers is not in the correct format. ([#69718](https://github.com/kubernetes/kubernetes/pull/69718), [@andyzhangx](https://g...

* Allow setting the Host header in a httpGet probe ([#24292](https://github.com/kubernetes/kubernetes/pull/24292), [@errm](https://github.com/errm))
* Bridge off-cluster traffic into services by masquerading. ([#24429](https://github.com/kubernetes/kubernetes/pull/24429), [@cjcullen](https://github.com/cjcullen))

* Allow setting the Host header in a httpGet probe ([#24292](https://github.com/kubernetes/kubernetes/pull/24292), [@errm](https://github.com/errm))
* Fix goroutine leak in ssh-tunnel healthcheck. ([#24487](https://github.com/kubernetes/kubernetes/pull/24487), [@cjcullen](https://github.com/cjcullen))

  cm.NodeAllocatableRoot(s.CgroupRoot, s.CgroupDriver)
  
  kubeDeps.CAdvisorInterface, err = cadvisor.New(imageFsInfoProvider, s.RootDirectory, cgroupRoots, cadvisor.UsingLegacyCadvisorStats(s.ContainerRuntime, s.RemoteRuntimeEndpoint))

* Allow Secret & ConfigMap keys to contain caps, dots, and underscores ([#25458](https://github.com/kubernetes/kubernetes/pull/25458), [@errm](https://github.com/errm))
* allow watching old resources with kubectl ([#27392](https://github.com/kubernetes/kubernetes/pull/27392), [@sjenning](https://github.com/sjenning))