Enable http pprof connections when pprof-address is set.

Add flag to specify the address where those connections listen.

Signed-off-by: David Calavera <david.calavera@gmail.com>

containerd/main.go

@@ -55,6 +55,10 @@ var daemonFlags = []cli.Flag{
 		Value: &cli.StringSlice{},
 		Usage: "specify additional runtime args",
 	},
+	cli.StringFlag{
+		Name:  "pprof-address",
+		Usage: "http address to listen for pprof events",
+	},
 }
 
 func main() {

containerd/main_linux.go

@@ -12,6 +12,7 @@ import (
 	"github.com/cloudfoundry/gosigar"
 	"github.com/codegangsta/cli"
 	"github.com/cyberdelia/go-metrics-graphite"
+	"github.com/docker/containerd/api/http/pprof"
 	"github.com/docker/containerd/osutils"
 	"github.com/docker/containerd/supervisor"
 	"github.com/rcrowley/go-metrics"
@@ -37,6 +38,10 @@ func setAppBefore(app *cli.App) {
 			if err := debugMetrics(context.GlobalDuration("metrics-interval"), context.GlobalString("graphite-address")); err != nil {
 				return err
 			}
+
+		}
+		if p := context.GlobalString("pprof-address"); len(p) > 0 {
+			pprof.Enable(p)
 		}
 		if err := checkLimits(); err != nil {
 			return err