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/function/test.go

@@ -30,6 +30,7 @@ import (
 
 	"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/httptrigger"
 	"github.com/fission/fission/pkg/fission-cli/console"
 	flagkey "github.com/fission/fission/pkg/fission-cli/flag/key"
@@ -37,18 +38,11 @@ import (
 )
 
 type TestSubCommand struct {
-	client *client.Client
+	cmd.CommandActioner
 }
 
 func Test(input cli.Input) error {
-	c, err := util.GetServer(input)
-	if err != nil {
-		return err
-	}
-	opts := TestSubCommand{
-		client: c,
-	}
-	return opts.do(input)
+	return (&TestSubCommand{}).do(input)
 }
 
 func (opts *TestSubCommand) do(input cli.Input) error {
@@ -124,7 +118,7 @@ func (opts *TestSubCommand) do(input cli.Input) error {
 	}
 
 	console.Errorf("Error calling function %s: %d; Please try again or fix the error: %s\n", m.Name, resp.StatusCode, string(body))
-	log, err := printPodLogs(opts.client, m)
+	log, err := printPodLogs(opts.Client(), m)
 	if err != nil {
 		console.Errorf("Error getting function logs from controller: %v. Try to get logs from log database.", err)
 		err = Log(input)
@@ -163,8 +157,8 @@ func doHTTPRequest(ctx context.Context, url string, headers []string, method, bo
 	return resp, nil
 }
 
-func printPodLogs(client *client.Client, fnMeta *metav1.ObjectMeta) (string, error) {
-	reader, statusCode, err := client.FunctionPodLogs(fnMeta)
+func printPodLogs(client client.Interface, fnMeta *metav1.ObjectMeta) (string, error) {
+	reader, statusCode, err := client.V1().Misc().PodLogs(fnMeta)
 	if err != nil {
 		return "", errors.Wrap(err, "error executing get logs request")
 	}