Allow dumped image to be transferred to a criu page server

--page-server to specify the IP address of criu page server
--port to specify the port of the criu page server

Docker-DCO-1.1-Signed-off-by: Hui Kang <hkang.sunysb@gmail.com>

container_linux.go

@@ -340,6 +340,14 @@ func (c *linuxContainer) Checkpoint(criuOpts *CriuOpts) error {
 		ExtUnixSk:      proto.Bool(criuOpts.ExternalUnixConnections),
 	}
 
+	// append optional criu opts, e.g., page-server and port
+	if criuOpts.Ps.Address != "" && criuOpts.Ps.Port != 0 {
+		rpcOpts.Ps = &criurpc.CriuPageServerInfo{
+			Address: proto.String(criuOpts.Ps.Address),
+			Port:    proto.Int32(criuOpts.Ps.Port),
+		}
+	}
+
 	t := criurpc.CriuReqType_DUMP
 	req := criurpc.CriuReq{
 		Type: &t,

criu_opts.go

@@ -1,10 +1,16 @@
 package libcontainer
 
-type CriuOpts struct {
-	ImagesDirectory         string // directory for storing image files
-	WorkDirectory           string // directory to cd and write logs/pidfiles/stats to
-	LeaveRunning            bool   // leave container in running state after checkpoint
-	TcpEstablished          bool   // checkpoint/restore established TCP connections
-	ExternalUnixConnections bool   // allow external unix connections
-	ShellJob                bool   // allow to dump and restore shell jobs
+type CriuPageServerInfo struct {
+	Address string // IP address of CRIU page server
+	Port    int32  // port number of CRIU page server
+}
+
+type CriuOpts struct {
+	ImagesDirectory         string              // directory for storing image files
+	WorkDirectory           string              // directory to cd and write logs/pidfiles/stats to
+	LeaveRunning            bool                // leave container in running state after checkpoint
+	TcpEstablished          bool                // checkpoint/restore established TCP connections
+	ExternalUnixConnections bool                // allow external unix connections
+	ShellJob                bool                // allow to dump and restore shell jobs
+	Ps                      *CriuPageServerInfo // allow to dump to criu page server
 }

nsinit/checkpoint.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"strconv"
 	"github.com/codegangsta/cli"
 	"github.com/docker/libcontainer"
 )
@@ -17,6 +18,8 @@ var checkpointCommand = cli.Command{
 		cli.BoolFlag{Name: "tcp-established", Usage: "allow open tcp connections"},
 		cli.BoolFlag{Name: "ext-unix-sk", Usage: "allow external unix sockets"},
 		cli.BoolFlag{Name: "shell-job", Usage: "allow shell jobs"},
+		cli.StringFlag{Name: "page-server", Value: "", Usage: "IP address of the page server"},
+		cli.StringFlag{Name: "port", Value: "", Usage: "port number of the page server"},
 	},
 	Action: func(context *cli.Context) {
 		imagePath := context.String("image-path")
@@ -28,14 +31,36 @@ var checkpointCommand = cli.Command{
 		if err != nil {
 			fatal(err)
 		}
-		if err := container.Checkpoint(&libcontainer.CriuOpts{
+
+		// these are the mandatory criu options for a container
+		criuOpts := &libcontainer.CriuOpts{
 			ImagesDirectory:         imagePath,
 			WorkDirectory:           context.String("work-path"),
 			LeaveRunning:            context.Bool("leave-running"),
 			TcpEstablished:          context.Bool("tcp-established"),
 			ExternalUnixConnections: context.Bool("ext-unix-sk"),
 			ShellJob:                context.Bool("shell-job"),
-		}); err != nil {
+		}
+
+		// xxx following criu opts are optional
+		// The dump image can be sent to a criu page server
+		var port string
+		if psAddress := context.String("page-server"); psAddress != "" {
+			if port = context.String("port"); port == "" {
+				fatal(fmt.Errorf("The --port number isn't specified"))
+			}
+
+			port_int, err := strconv.Atoi(port)
+			if err != nil {
+				fatal(fmt.Errorf("Invalid port number"))
+			}
+			criuOpts.Ps = &libcontainer.CriuPageServerInfo{
+				Address: psAddress,
+				Port:    int32(port_int),
+			}
+		}
+
+		if err := container.Checkpoint(criuOpts); err != nil {
 			fatal(err)
 		}
 	},