* Rename variables and functions to match Go convention.
For example, UsageError --> UsageErrorf.
* Remove redundant or unreachable code.
* Simplify some utility functions (no functionality changes).
* Fix hanging 'if { return } else { return }' constructs.
* Fix several incorrect printf verbs.
Automatic merge from submit-queue
fix --local flag for kubectl commands
Fixes https://github.com/kubernetes/kubernetes/issues/47079
**Release note**:
```release-note
NONE
```
Fixes the `--local` flag for `kubectl set ...` sub-commands.
**As of the 1.7 release**, `PrinterForCommand` was updated to [use a mapper and typer for unstructured objects](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubectl/cmd/util/factory_builder.go#L52), which further prevented the use of `--local` when there was no connection to an api server.
**before** (with no connection to a server)
```
$ kubectl set resources -f pod.json --limits=cpu=200m,memory=512Mi --local
error: unable to connect to a server to handle "pods": Get https://10.13.137.149:8443/api: dial tcp 10.13.137.149:8443: getsockopt: connection refused
```
**after** (with no connection to a server)
```
$ kubectl set resources -f pod.json --limits=cpu=200m,memory=512Mi --local
NAME READY STATUS RESTARTS AGE
mypod 0/1 0 <unknown>
```
cc @smarterclayton @fabianofranz
Get command now uses metadata x-kubernetes-print-columns, if present, in Openapi schema
to format output for a resource. This functionality is guarded by a boolean
flag 'use-openapi-print-columns'.
This fixes#38779.
This allows us to avoid case in which printers.GetStandardPrinter
returns nil for both printer and err removing any potential panics that
may arise throughout kubectl commands.
Please see #38779 and #38112 for complete context.
Add comment explaining adding handlers to printers.HumanReadablePrinter
also remove an unnecessary conversion of printers.HumanReadablePrinter
to printers.ResourcePrinter.
The factory knows all possible types, and should abstract the process of
creating all printers. A future refactor can further reduce the
dependencies between printer code and internal types.
Switch to allowing missing keys in jsonpath templates by default.
Add support for allowing/disallowing missing keys in go templates
(default=allow).
Add --allow-missing-template-keys flag to control this behavior
(default=true / allow missing keys).
Automatic merge from submit-queue
Add json,yaml output format support to kubectl create, kubectl apply
Fixes: https://github.com/kubernetes/kubernetes/issues/37390
**Release note**:
```release-note
Added support for printing in all supported `--output` formats to `kubectl create ...` and `kubectl apply ...`
```
This patch adds the ability to specify an output format other than
"name" to `kubectl create ...`. It can be used in conjunction with the
`--dry-run` option. Converts unstructured objects into known types in
order to support all `--output` values.
The patch prints `*resource.Info`s returned by the server. If a resource does not yet exist (and the `--dry-run` option is not set), the resource is created and printed in the specified format.
@kubernetes/cli-review @fabianofranz
This patch adds the ability to specify an output format other than
"name" to `kubectl create ...`. It can be used in conjunction with the
`--dry-run` option. Converts unstructured objects into known types in
order to support all `--output` values.
