Simplify gomu cmd registering (#2249)

* Use internal runtime package for gomu run

This change refactors the `gomu run` command to use Go Micro's internal
runtime package in order to run services. Not only does this clean up
duplicate functionality between Go Micro and Gomu, but also adds the
feature to Gomu to run remote projects. For example, the following
command pulls in a remote project and runs it locally.

```bash
gomu run github.com/auditemarlow/helloworld
```

The `gomu run` command remains backwards compatible. By invoking `gomu
run` in a Go Micro project directory, Gomu will simply run that project.

* Simplify Gomu's command registering

By leveraging Go's `init()` function, we can simplify registering
commands just a tad.

cmd/gomu/cmd/cli/call/call.go

@@ -12,13 +12,12 @@ import (
 	"github.com/urfave/cli/v2"
 )
 
-// NewCommand returns a new call cli command.
-func NewCommand() *cli.Command {
-	return &cli.Command{
+func init() {
+	cmd.Register(&cli.Command{
 		Name:   "call",
 		Usage:  "Call a service, e.g. " + cmd.App().Name + " call helloworld Helloworld.Call '{\"name\": \"John\"}'",
 		Action: RunCall,
-	}
+	})
 }
 
 // RunCall calls a service endpoint and prints its response. Exits on error.

cmd/gomu/cmd/cli/cli.go

@@ -1,28 +1,10 @@
 package cli
 
 import (
-	"sort"
-
-	"github.com/asim/go-micro/cmd/gomu/cmd"
-	"github.com/asim/go-micro/cmd/gomu/cmd/cli/call"
-	"github.com/asim/go-micro/cmd/gomu/cmd/cli/describe"
-	"github.com/asim/go-micro/cmd/gomu/cmd/cli/new"
-	"github.com/asim/go-micro/cmd/gomu/cmd/cli/run"
-	"github.com/asim/go-micro/cmd/gomu/cmd/cli/services"
-	"github.com/asim/go-micro/cmd/gomu/cmd/cli/stream"
-	mcli "github.com/urfave/cli/v2"
+	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/call"
+	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/describe"
+	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/new"
+	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/run"
+	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/services"
+	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/stream"
 )
-
-func init() {
-	cmd.Register(
-		call.NewCommand(),
-		describe.NewCommand(),
-		new.NewCommand(),
-		run.NewCommand(),
-		services.NewCommand(),
-		stream.NewCommand(),
-	)
-
-	sort.Sort(mcli.FlagsByName(cmd.App().Flags))
-	sort.Sort(mcli.CommandsByName(cmd.App().Commands))
-}

cmd/gomu/cmd/cli/describe/describe.go

@@ -13,9 +13,8 @@ var flags []cli.Flag = []cli.Flag{
 	},
 }
 
-// NewCommand returns a new describe cli command.
-func NewCommand() *cli.Command {
-	return &cli.Command{
+func init() {
+	cmd.Register(&cli.Command{
 		Name:  "describe",
 		Usage: "Describe a resource",
 		Subcommands: []*cli.Command{
@@ -27,5 +26,5 @@ func NewCommand() *cli.Command {
 				Flags:   flags,
 			},
 		},
-	}
+	})
 }

cmd/gomu/cmd/cli/new/new.go

@@ -40,8 +40,8 @@ type file struct {
 }
 
 // NewCommand returns a new new cli command.
-func NewCommand() *cli.Command {
-	return &cli.Command{
+func init() {
+	cmd.Register(&cli.Command{
 		Name:  "new",
 		Usage: "Create a project template",
 		Subcommands: []*cli.Command{
@@ -64,7 +64,7 @@ func NewCommand() *cli.Command {
 				Flags:  flags,
 			},
 		},
-	}
+	})
 }
 
 func Client(ctx *cli.Context) error {

cmd/gomu/cmd/cli/run/run.go

@@ -33,14 +33,13 @@ var (
 	}
 )
 
-// NewCommand returns a new run command.
-func NewCommand() *cli.Command {
-	return &cli.Command{
+func init() {
+	cmd.Register(&cli.Command{
 		Name:   "run",
 		Usage:  "Build and run a service continuously, e.g. gomu run [github.com/auditemarlow/helloworld]",
 		Flags:  flags,
 		Action: Run,
-	}
+	})
 }
 
 // Run runs a service and watches the project directory for change events. On

cmd/gomu/cmd/cli/services/services.go

@@ -8,13 +8,12 @@ import (
 	"github.com/urfave/cli/v2"
 )
 
-// NewCommand returns a new services command.
-func NewCommand() *cli.Command {
-	return &cli.Command{
+func init() {
+	cmd.Register(&cli.Command{
 		Name:   "services",
 		Usage:  "List services in the registry",
 		Action: List,
-	}
+	})
 }
 
 // List fetches running services from the registry and lists them. Exits on

cmd/gomu/cmd/cli/stream/stream.go

@@ -5,9 +5,8 @@ import (
 	"github.com/urfave/cli/v2"
 )
 
-// NewCommand returns a new stream command.
-func NewCommand() *cli.Command {
-	return &cli.Command{
+func init() {
+	cmd.Register(&cli.Command{
 		Name:  "stream",
 		Usage: "Create a service stream",
 		Subcommands: []*cli.Command{
@@ -24,5 +23,5 @@ func NewCommand() *cli.Command {
 				Action:  Server,
 			},
 		},
-	}
+	})
 }