Add controller API client interface (#1467)

This PR adds an interface for controller API client, it allows us to
implement mock API client for unit testing with ease and we are
able to generate spec file without accessing the real Fission server.

pkg/fission-cli/cmd/package/create.go

@@ -30,6 +30,7 @@ import (
 	fv1 "github.com/fission/fission/pkg/apis/fission.io/v1"
 	"github.com/fission/fission/pkg/controller/client"
 	"github.com/fission/fission/pkg/fission-cli/cliwrapper/cli"
+	"github.com/fission/fission/pkg/fission-cli/cmd"
 	"github.com/fission/fission/pkg/fission-cli/cmd/spec"
 	"github.com/fission/fission/pkg/fission-cli/console"
 	flagkey "github.com/fission/fission/pkg/fission-cli/flag/key"
@@ -37,18 +38,11 @@ import (
 )
 
 type CreateSubCommand struct {
-	client *client.Client
+	cmd.CommandActioner
 }
 
 func Create(input cli.Input) error {
-	c, err := util.GetServer(input)
-	if err != nil {
-		return err
-	}
-	opts := CreateSubCommand{
-		client: c,
-	}
-	return opts.do(input)
+	return (&CreateSubCommand{}).do(input)
 }
 
 func (opts *CreateSubCommand) do(input cli.Input) error {
@@ -114,14 +108,14 @@ func (opts *CreateSubCommand) run(input cli.Input) error {
 		specFile = fmt.Sprintf("package-%v.yaml", pkgName)
 	}
 
-	_, err := CreatePackage(input, opts.client, pkgName, pkgNamespace, envName, envNamespace,
+	_, err := CreatePackage(input, opts.Client(), pkgName, pkgNamespace, envName, envNamespace,
 		srcArchiveFiles, deployArchiveFiles, buildcmd, specDir, specFile, noZip)
 
 	return err
 }
 
 // TODO: get all necessary value from CLI input directly
-func CreatePackage(input cli.Input, client *client.Client, pkgName string, pkgNamespace string, envName string, envNamespace string,
+func CreatePackage(input cli.Input, client client.Interface, pkgName string, pkgNamespace string, envName string, envNamespace string,
 	srcArchiveFiles []string, deployArchiveFiles []string, buildcmd string, specDir string, specFile string, noZip bool) (*metav1.ObjectMeta, error) {
 
 	insecure := input.Bool(flagkey.PkgInsecure)
@@ -201,7 +195,7 @@ func CreatePackage(input cli.Input, client *client.Client, pkgName string, pkgNa
 		}
 		return &pkg.Metadata, nil
 	} else {
-		pkgMetadata, err := client.PackageCreate(pkg)
+		pkgMetadata, err := client.V1().Package().Create(pkg)
 		if err != nil {
 			return nil, errors.Wrap(err, "error creating package")
 		}