Make dockerd debuggable

Signed-off-by: John Howard <jhoward@microsoft.com>

docker.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/docker/docker/dockerversion"
+	flag "github.com/docker/docker/pkg/mflag"
+	"github.com/docker/docker/pkg/term"
+	"github.com/docker/docker/utils"
+)
+
+func main() {
+	// Set terminal emulation based on platform as required.
+	stdin, stdout, stderr := term.StdStreams()
+
+	logrus.SetOutput(stderr)
+
+	flag.Merge(flag.CommandLine, clientFlags.FlagSet, commonFlags.FlagSet)
+
+	flag.Usage = func() {
+		fmt.Fprint(stdout, "Usage: docker [OPTIONS] COMMAND [arg...]\n       docker [ --help | -v | --version ]\n\n")
+		fmt.Fprint(stdout, "A self-sufficient runtime for containers.\n\nOptions:\n")
+
+		flag.CommandLine.SetOutput(stdout)
+		flag.PrintDefaults()
+
+		help := "\nCommands:\n"
+
+		for _, cmd := range dockerCommands {
+			help += fmt.Sprintf("    %-10.10s%s\n", cmd.Name, cmd.Description)
+		}
+
+		help += "\nRun 'docker COMMAND --help' for more information on a command."
+		fmt.Fprintf(stdout, "%s\n", help)
+	}
+
+	flag.Parse()
+
+	if *flVersion {
+		showVersion()
+		return
+	}
+
+	if *flHelp {
+		// if global flag --help is present, regardless of what other options and commands there are,
+		// just print the usage.
+		flag.Usage()
+		return
+	}
+
+	clientCli := client.NewDockerCli(stdin, stdout, stderr, clientFlags)
+
+	c := cli.New(clientCli, NewDaemonProxy())
+	if err := c.Run(flag.Args()...); err != nil {
+		if sterr, ok := err.(cli.StatusError); ok {
+			if sterr.Status != "" {
+				fmt.Fprintln(stderr, sterr.Status)
+				os.Exit(1)
+			}
+			os.Exit(sterr.StatusCode)
+		}
+		fmt.Fprintln(stderr, err)
+		os.Exit(1)
+	}
+}
+
+func showVersion() {
+	if utils.ExperimentalBuild() {
+		fmt.Printf("Docker version %s, build %s, experimental\n", dockerversion.Version, dockerversion.GitCommit)
+	} else {
+		fmt.Printf("Docker version %s, build %s\n", dockerversion.Version, dockerversion.GitCommit)
+	}
+}