cmd: introduce a shim to expose Stdout/Stderr writers

This will allow commands to do the right thing, and write to the proper
output stream.

command/cli/cli.go

@@ -0,0 +1,32 @@
+package cli
+
+import (
+	"io"
+
+	mcli "github.com/mitchellh/cli"
+)
+
+// Ui implements the mitchellh/cli.Ui interface, while exposing the underlying
+// io.Writer used for stdout and stderr.
+// TODO: rename to UI to match golang style guide
+type Ui interface {
+	mcli.Ui
+	Stdout() io.Writer
+	Stderr() io.Writer
+}
+
+// BasicUI augments mitchellh/cli.BasicUi by exposing the underlying io.Writer.
+type BasicUI struct {
+	mcli.BasicUi
+}
+
+func (b *BasicUI) Stdout() io.Writer {
+	return b.BasicUi.Writer
+}
+
+func (b *BasicUI) Stderr() io.Writer {
+	return b.BasicUi.ErrorWriter
+}
+
+// Command is an alias to reduce the diff. It can be removed at any time.
+type Command mcli.Command

command/commands_oss.go

@@ -41,6 +41,7 @@ import (
 	catlistdc "github.com/hashicorp/consul/command/catalog/list/dc"
 	catlistnodes "github.com/hashicorp/consul/command/catalog/list/nodes"
 	catlistsvc "github.com/hashicorp/consul/command/catalog/list/services"
+	"github.com/hashicorp/consul/command/cli"
 	"github.com/hashicorp/consul/command/config"
 	configdelete "github.com/hashicorp/consul/command/config/delete"
 	configlist "github.com/hashicorp/consul/command/config/list"
@@ -108,8 +109,6 @@ import (
 	"github.com/hashicorp/consul/command/validate"
 	"github.com/hashicorp/consul/command/version"
 	"github.com/hashicorp/consul/command/watch"
-
-	"github.com/mitchellh/cli"
 )
 
 func init() {

command/registry.go

@@ -6,7 +6,9 @@ import (
 	"os/signal"
 	"syscall"
 
-	"github.com/mitchellh/cli"
+	mcli "github.com/mitchellh/cli"
+
+	"github.com/hashicorp/consul/command/cli"
 )
 
 // Factory is a function that returns a new instance of a CLI-sub command.
@@ -24,14 +26,14 @@ func Register(name string, fn Factory) {
 	registry[name] = fn
 }
 
-// Map returns a realized mapping of available CLI commands in a format that
+// CommandsFromRegistry returns a realized mapping of available CLI commands in a format that
 // the CLI class can consume. This should be called after all registration is
 // complete.
-func Map(ui cli.Ui) map[string]cli.CommandFactory {
-	m := make(map[string]cli.CommandFactory)
+func CommandsFromRegistry(ui cli.Ui) map[string]mcli.CommandFactory {
+	m := make(map[string]mcli.CommandFactory)
 	for name, fn := range registry {
 		thisFn := fn
-		m[name] = func() (cli.Command, error) {
+		m[name] = func() (mcli.Command, error) {
 			return thisFn(ui)
 		}
 	}

main.go

@@ -6,11 +6,13 @@ import (
 	"log"
 	"os"
 
+	mcli "github.com/mitchellh/cli"
+
 	"github.com/hashicorp/consul/command"
+	"github.com/hashicorp/consul/command/cli"
 	"github.com/hashicorp/consul/command/version"
 	"github.com/hashicorp/consul/lib"
 	_ "github.com/hashicorp/consul/service_os"
-	"github.com/mitchellh/cli"
 )
 
 func init() {
@@ -24,19 +26,21 @@ func main() {
 func realMain() int {
 	log.SetOutput(ioutil.Discard)
 
-	ui := &cli.BasicUi{Writer: os.Stdout, ErrorWriter: os.Stderr}
-	cmds := command.Map(ui)
+	ui := &cli.BasicUI{
+		BasicUi: mcli.BasicUi{Writer: os.Stdout, ErrorWriter: os.Stderr},
+	}
+	cmds := command.CommandsFromRegistry(ui)
 	var names []string
 	for c := range cmds {
 		names = append(names, c)
 	}
 
-	cli := &cli.CLI{
+	cli := &mcli.CLI{
 		Args:         os.Args[1:],
 		Commands:     cmds,
 		Autocomplete: true,
 		Name:         "consul",
-		HelpFunc:     cli.FilteredHelpFunc(names, cli.BasicHelpFunc("consul")),
+		HelpFunc:     mcli.FilteredHelpFunc(names, mcli.BasicHelpFunc("consul")),
 		HelpWriter:   os.Stdout,
 		ErrorWriter:  os.Stderr,
 	}