<-chan <-chan int  // same as <-chan (<-chan int)
chan (<-chan int)
</pre>

<p>
A new, initialized channel
value can be made using the built-in function
<a href="#Making_slices_maps_and_channels"><code>make</code></a>,
which takes the channel type and an optional <i>capacity</i> as arguments:
</p>

<pre>
make(chan int, 100)
</pre>

<p>

- The Kubelet now properly requests protobuf objects where they are supported from the apiserver, reducing load in large clusters. ([#75602](https://github.com/kubernetes/kubernetes/pull/75602), [@smarterclayton](https://github.com/smarterclayton))

### OpenStack

ernetes/kubernetes/pull/58502), [@dixudx](https://github.com/dixudx))

* Authentication information for OpenStack cloud provider can now be specified as environment variables. When we convert the OpenStack cloud provider to run in an external process, we can now use the kubernetes Secrets capability to inject the OS_* variables. This way we can specify the cloud configuration as a configmap, and specify secrets for the userid/password information. The configmap is mounted as a file, and...

* kube-controller-manager can now start the quota controller when discovery results can only be partially determined. ([#67433](https://github.com/kubernetes/kubernetes/pull/67433), [@deads2k](https://github.com/deads2k))

  // to see the host machine. Most containers will NOT need this.
  // More info: https://kubernetes.io/docs/concepts/storage/volumes#hostpath
  // ---
  // TODO(jonesdl) We need to restrict who can use host directory mounts and who can/can not
  // mount host directories as read/write.
  // +optional
  optional HostPathVolumeSource hostPath = 1;

  // emptyDir represents a temporary directory that shares a pod's lifetime.

* [stable] The PV spec for Azure File, CephFS, iSCSI, and Glusterfs is modified to reference namespaced resources.

* [stable] You can now customize the iSCSI initiator name per volume in the iSCSI volume plugin.

For example, a plugin that implements Score and Filter extensions can be simultaneously enabled for both.
This means entire plugins can be enabled and disabled without having to manually edit individual extension point settings.
These extension points can now be abstracted away due to their irrelevance for most users.

### CSI Migration updates

  - [Changelog since v1.21.4](#changelog-since-v1214)
  - [Important Security Information](#important-security-information)
    - [CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access](#cve-2021-25741-symlink-exchange-can-allow-host-filesystem-access)
  - [Changes by Kind](#changes-by-kind-8)
    - [Feature](#feature-6)
    - [Bug or Regression](#bug-or-regression-8)

- Kubelet: a "maxParallelImagePulls" field can now be specified in the kubelet configuration file to control how many image pulls the kubelet can perform in parallel. ([#115220](https://github.com/kubernetes/kubernetes/pull/115220), [@ruiwen-zhao](https://github.com/ruiwen-zhao)) [SIG API Machinery, Node and Scalability]

### IPv4/IPv6 run

IPv4/IPv6 dual-stack has been reimplemented for 1.20 to support dual-stack Services, based on user and community feedback. If your cluster has dual-stack enabled, you can create Services which can use IPv4, IPv6, or both, and you can change this setting for existing Services. Details are available in updated [IPv4/IPv6 dual-stack docs](https://docs.k8s.io/concepts/services-networking/dual-stack/), which cover the nuanced array of options.