add version and git commit at compile time

Makefile

@@ -1,10 +1,19 @@
 RUNC_TEST_IMAGE=runc_test
 PROJECT=github.com/opencontainers/runc
 TEST_DOCKERFILE=script/test_Dockerfile
+VERSION := $(shell cat VERSION)
 export GOPATH:=$(CURDIR)/Godeps/_workspace:$(GOPATH)
 
+GITCOMMIT := $(shell git rev-parse --short HEAD)
+GITUNTRACKEDCHANGES := $(shell git status --porcelain --untracked-files=no)
+ifneq ($(GITUNTRACKEDCHANGES),)
+	GITCOMMIT := $(GITCOMMIT)-dirty
+endif
+CTIMEVAR=-X $(PROJECT)/version.GitCommit '$(GITCOMMIT)' -X $(PROJECT)/version.Version '$(VERSION)'
+GO_LDFLAGS=-ldflags "-w $(CTIMEVAR)"
+
 all:
-	go build -o runc .
+	go build -o runc ${GO_LDFLAGS} .
 
 vet:
 	go get golang.org/x/tools/cmd/vet
@@ -26,7 +35,7 @@ install:
 	cp runc /usr/local/bin/runc
 
 clean:
-	rm runc
+	rm -f runc
 
 validate: vet
 	script/validate-gofmt

VERSION

@@ -0,0 +1 @@
+0.2

main.go

@@ -5,11 +5,11 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/codegangsta/cli"
+	"github.com/opencontainers/runc/version"
 )
 
-const (
-	version = "0.2"
-	usage   = `Open Container Initiative runtime
+var (
+	usage = `Open Container Initiative runtime
 
 runc is a command line client for running applications packaged according to
 the Open Container Format (OCF) and is a compliant implementation of the
@@ -30,14 +30,16 @@ or
 	cd /mycontainer
 	runc start [ spec-file ]
 
-If not specified, the default value for the 'spec-file' is 'config.json'. `
+If not specified, the default value for the 'spec-file' is 'config.json'. 
+
+Built from git commit: ` + version.GitCommit
 )
 
 func main() {
 	app := cli.NewApp()
 	app.Name = "runc"
 	app.Usage = usage
-	app.Version = version
+	app.Version = version.Version
 	app.Flags = []cli.Flag{
 		cli.StringFlag{
 			Name:  "id",

version/version.go

@@ -0,0 +1,7 @@
+package version
+
+// Version indicates which version of the binary is running.
+var Version string
+
+// GitCommit indicates which git hash the binary was built off of
+var GitCommit string