pkg crypto/x509, const PureEd25519 SignatureAlgorithm
pkg database/sql, method (*Conn) Raw(func(interface{}) error) error
pkg database/sql, method (*NullInt32) Scan(interface{}) error
pkg database/sql, method (NullInt32) Value() (driver.Value, error)
pkg database/sql, method (*NullTime) Scan(interface{}) error
pkg database/sql, method (NullTime) Value() (driver.Value, error)
pkg database/sql, type NullInt32 struct

- Fixed the wrong hierarchical structure for both the child span and the parent span (i.e. `SerializeObject` and `List`). In the past, some children's spans appeared parallel to their parents. ([#127551](https://github.com/kubernetes/kubernetes/pull/127551), [@carlory](https://github.com/carlory)) [SIG API Machinery and Instrumentation]

* You can now set a maximum volume count ([ref](https://github.com/kubernetes/enhancements/issues/554))
* You can now do environment variable expansion in a subpath mount. ([ref](https://github.com/kubernetes/enhancements/issues/559))
* You can now run containers in a pod as a particular group. ([ref](https://github.com/kubernetes/enhancements/issues/213))

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...

- github.com/prometheus/tsdb: [v0.7.1](https://github.com/prometheus/tsdb/tree/v0.7.1)
- github.com/ryanuber/columnize: [9b3edd6](https://github.com/ryanuber/columnize/tree/9b3edd6)
- github.com/sean-/seed: [e2103e2](https://github.com/sean-/seed/tree/e2103e2)
- github.com/shurcooL/sanitized_anchor_name: [v1.0.0](https://github.com/shurcooL/sanitized_anchor_name/tree/v1.0.0)

* Add a feature to the scheduler to score fewer than all nodes in every scheduling cycle. This can improve performance of the scheduler in large clusters. ([#66733](https://github.com/kubernetes/kubernetes/pull/66733), [@bsalamat](https://github.com/bsalamat))

### 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.

- Kubeadm: Added support during the preflight check "CreateJob" of "kubeadm upgrade" to check if there are no nodes where a Pod can be scheduled. If there are none, show a warning and skip this preflight check. This can happen in single node clusters where the only node was drained....

- consumers of the 'certificatesigningrequests/approval' API must now have permission to 'approve' CSRs for the specific signer requested by the CSR. More information on the new signerName field and the required authorization can be found at https://kubernetes.io/docs/reference/access-authn-authz/certificate-signing-requests#authorization...

- the IP allocator in v1.17.0 can return errors such as `the cluster IP <ip> for service <service-name> is not within the service CIDR <cidr>; please recreate` in the logs of the kube-apiserver. The cause...