add port-forward examples for sevice
```
$ kubectl port-forward --help
........
Examples:
# Listen on ports 5000 and 6000 locally, forwarding data to/from ports 5000 and 6000 in the pod
kubectl port-forward pod/mypod 5000 6000
# Listen on ports 5000 and 6000 locally, forwarding data to/from ports 5000 and 6000 in a pod selected by the
deployment
kubectl port-forward deployment/mydeployment 5000 6000
# Listen on ports 5000 and 6000 locally, forwarding data to/from ports 5000 and 6000 in a pod selected by the
service
kubectl port-forward service/myservice 5000 6000
# Listen on port 8888 locally, forwarding to 5000 in the pod
kubectl port-forward pod/mypod 8888:5000
# Listen on a random port locally, forwarding to 5000 in the pod
kubectl port-forward pod/mypod :5000
........
```
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**What this PR does / why we need it**:
add port-forward examples for sevice
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
**Special notes for your reviewer**:
**Release note**:
<!-- Write your release note:
1. Enter your extended release note in the below block. If the PR requires additional action from users switching to the new release, include the string "action required".
2. If no release note is required, just write "NONE".
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```release-note
add port-forward examples for sevice
```
Automatic merge from submit-queue (batch tested with PRs 50229, 50973, 50976, 51085, 51084)
Remove duplicate command example
**What this PR does / why we need it**:
`kubectl port-forward --help` currently contains a duplicate example. This PR removes the duplicate.
```release-note
/release-note Remove duplicate command example from `kubectl port-forward --help`
```
/sig cli
/kind cleanup
/kind documentation
* 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.
Module remotecommand originally part of kubernetes/pkg/client/unversioned was moved
to client-go/tools, and will be used as authoritative in kubectl, e2e and other places.
Module remotecommand relies on util/exec module which will be copied to client-go/pkg/util
Automatic merge from submit-queue
Removed a space in portforward.go.
**What this PR does / why we need it**:
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
```
The one side effect is that for the "kubectl help" commands a newline
is prepended to output, which will alter the yaml output.
Here we use dedent to format the code to match the output.
hack/update-generated-docs.sh has been run and the affected files have
been added.
Note: for describe.go we added a period to the end of an output message.
The current executor structure is too dependent on client.Request
and client.Config. In order to do an attach from the server, it needs
to be possible to create an Executor from crypto/tls#TLSConfig and to
bypassing having a client.Request.
Changes:
* remotecommand.spdyExecutor - handles upgrading a request to SPDY and getting a connection
* remotecommand.NewAttach / New - moved to exec / portforward / attach since they handle requests
* Remove request.Upgrade() - it's too coupled to SPDY, and can live with the spdyExecutor
* Add request.VersionedParams(runtime.Object, runtime.ObjectConvertor) to handle object -> query transform
