commands/operator-sdk: change defintion of operator-sdk new

[fanminshi]

new now requires flags --api-group and --api-kind because providing defaults to those value are not useful; hence un-useful defaults shouldn't be defaults.

[fanminshi]

cc/ @hasbro17 @hongchaodeng @xiang90

[hongchaodeng]

Based on initial feedback, most members of the group like to have flags to indicate the meeting of the last two params. Let's make apigroup and kind flags.

[fanminshi]

based on private discussion, we are going to have operator-sdk new [project-name] --api-group --kind and make --api-group and --kind required flags.

[hongchaodeng]

See the workflow: https://github.com/coreos/operator-sdk#creating-a-new-project

It is:

cd $GOPATH/src/github.com/example.com/
 operator-sdk new app-operator
cd app-operator

[fanminshi]

good catch on this one!

[fanminshi]

all fixed. PTAL

[fanminshi]

manual test:

$ ./operator-sdk new
Error: Required flag(s) "api-group", "kind" have/has not been set
Usage:
  operator-sdk new [options] <project-name> [flags]

Flags:
      --api-group string   Kubernetes API Group and has a format of $GROUP_NAME/$VERSION (e.g app.example.com/v1alpha1)
  -h, --help               help for new
      --kind string        Kubernetes CustomResourceDefintion kind. (e.g AppService)

Required flag(s) "api-group", "kind" have/has not been set

[hongchaodeng]

Usage:
operator-sdk new [options] [flags]

operator-sdk new <project-name> [required-flags] [options]

[hongchaodeng]

LGTM after nit

[fanminshi]

the best i can do is operator-sdk new <project-name> [required-flags] [flags] the latter [flags] is added by cobra; so i have no control of it.

[hongchaodeng]

Sounds good

[fanminshi]

final output:

$ ./operator-sdk new -h
The operator-sdk new command creates a new operator application and
	generates a default directory layout based on the input <project-name>.

	<project-name> is the project name of the new operator. (e.g app-operator)

	--api-group and --kind are required flags to generate the new operator application.

	For example,
	$ mkdir $GOPATH/src/github.com/example.com/
	$ cd $GOPATH/src/github.com/example.com/
	$ operator-sdk new app-operator --api-group=app.example.com --kind=AppService
	generates a skeletal app-operator application in $GOPATH/src/github.com/example.com/app-operator.

Usage:
  operator-sdk new <project-name> [required-flags] [flags]

Flags:
      --api-group string   Kubernetes API Group and has a format of $GROUP_NAME/$VERSION (e.g app.example.com/v1alpha1)
  -h, --help               help for new
      --kind string        Kubernetes CustomResourceDefintion kind. (e.g AppService)