From 3e53aab4ce6e8162310509e1ba84e885e999e9dd Mon Sep 17 00:00:00 2001
From: Rolf Neugebauer <rolf.neugebauer@docker.com>
Date: Wed, 5 Apr 2017 23:53:35 +0100
Subject: [PATCH] cli: Add a 'version' version

Pass version and git commit hash from the Makefile
into main.go. Add a 'version' subcommand to print
the information.

While at it also tweak the help output to only print the
command name and not the entire path.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
---
 Makefile             |  7 +++++--
 src/cmd/moby/main.go | 20 ++++++++++++++++++--
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 8df6a3278..c06af4476 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,10 @@
 default: bin/moby moby-initrd.img
 all: default
 
-GO_COMPILE=mobylinux/go-compile:3afebc59c5cde31024493c3f91e6102d584a30b9@sha256:e0786141ea7df8ba5735b63f2a24b4ade9eae5a02b0e04c4fca33b425ec69b0a
+VERSION="0.0" # dummy for now
+GIT_COMMIT=$(shell git rev-list -1 HEAD)
+
+GO_COMPILE=mobylinux/go-compile:a2ff853b00d687f845d0f67189fa645a567c006e@sha256:09fff8a5c022fc9ead35b2779209c043196b09193c6e61d98603d402c0971f03
 
 GOOS=$(shell uname -s | tr '[:upper:]' '[:lower:]')
 GOARCH=amd64
@@ -16,7 +19,7 @@ endif
 MOBY_DEPS=$(wildcard src/cmd/moby/*.go) Makefile vendor.conf
 MOBY_DEPS+=$(wildcard src/initrd/*.go) $(wildcard src/pad4/*.go)
 bin/moby: $(MOBY_DEPS) | bin
-	tar cf - vendor src/initrd src/pad4 -C src/cmd/moby . | docker run --rm --net=none --log-driver=none -i $(CROSS) $(GO_COMPILE) --package github.com/docker/moby -o $@ | tar xf -
+	tar cf - vendor src/initrd src/pad4 -C src/cmd/moby . | docker run --rm --net=none --log-driver=none -i $(CROSS) $(GO_COMPILE) --package github.com/docker/moby --ldflags "-X main.GitCommit=$(GIT_COMMIT) -X main.Version=$(VERSION)" -o $@ | tar xf -
 	touch $@
 
 INFRAKIT_DEPS=$(wildcard src/cmd/infrakit-instance-hyperkit/*.go) Makefile vendor.conf
diff --git a/src/cmd/moby/main.go b/src/cmd/moby/main.go
index 8496624bc..6ccf996a4 100644
--- a/src/cmd/moby/main.go
+++ b/src/cmd/moby/main.go
@@ -4,12 +4,19 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"path/filepath"
 
 	log "github.com/Sirupsen/logrus"
 )
 
 var (
 	defaultLogFormatter = &log.TextFormatter{}
+
+	// Version is the human-readable version
+	Version = "unknown"
+
+	// GitCommit hash, set at compile time
+	GitCommit = "unknown"
 )
 
 // infoFormatter overrides the default format for Info() log events to
@@ -24,15 +31,22 @@ func (f *infoFormatter) Format(entry *log.Entry) ([]byte, error) {
 	return defaultLogFormatter.Format(entry)
 }
 
+func version() {
+	fmt.Printf("%s version %s\n", filepath.Base(os.Args[0]), Version)
+	fmt.Printf("commit: %s\n", GitCommit)
+	os.Exit(0)
+}
+
 func main() {
 	flag.Usage = func() {
-		fmt.Printf("USAGE: %s [options] COMMAND\n\n", os.Args[0])
+		fmt.Printf("USAGE: %s [options] COMMAND\n\n", filepath.Base(os.Args[0]))
 		fmt.Printf("Commands:\n")
 		fmt.Printf("  build       Build a Moby image from a YAML file\n")
 		fmt.Printf("  run         Run a Moby image on a local hypervisor\n")
+		fmt.Printf("  version     Print version information\n")
 		fmt.Printf("  help        Print this message\n")
 		fmt.Printf("\n")
-		fmt.Printf("Run '%s COMMAND --help' for more information on the command\n", os.Args[0])
+		fmt.Printf("Run '%s COMMAND --help' for more information on the command\n", filepath.Base(os.Args[0]))
 		fmt.Printf("\n")
 		fmt.Printf("Options:\n")
 		flag.PrintDefaults()
@@ -69,6 +83,8 @@ func main() {
 		build(args[1:])
 	case "run":
 		run(args[1:])
+	case "version":
+		version()
 	case "help":
 		flag.Usage()
 	default: