adds list command, and a timestamp in the container state

Signed-off-by: Mike Brown <brownwm@us.ibm.com>

libcontainer/container.go

@@ -6,6 +6,7 @@ package libcontainer
 
 import (
 	"os"
+	"time"
 
 	"github.com/opencontainers/runc/libcontainer/configs"
 )
@@ -56,9 +57,12 @@ type BaseState struct {
 	// InitProcessPid is the init process id in the parent namespace.
 	InitProcessPid int `json:"init_process_pid"`
 
-	// InitProcessStartTime is the init process start time.
+	// InitProcessStartTime is the init process start time in clock cycles since boot time.
 	InitProcessStartTime string `json:"init_process_start"`
 
+	// CreatedTime is the unix timestamp for the creation time of the container in UTC
+	CreatedTime time.Time `json:"created_time"`
+
 	// Config is the container's configuration.
 	Config configs.Config `json:"config"`
 }

libcontainer/container_linux.go

@@ -15,6 +15,7 @@ import (
 	"strings"
 	"sync"
 	"syscall"
+	"time"
 
 	"github.com/Sirupsen/logrus"
 	"github.com/golang/protobuf/proto"
@@ -38,6 +39,7 @@ type linuxContainer struct {
 	m             sync.Mutex
 	criuVersion   int
 	state         containerState
+	createdTime   time.Time
 }
 
 // State represents a running container's state
@@ -117,6 +119,11 @@ func (c *linuxContainer) ID() string {
 	return c.id
 }
 
+// CreatedTime returns the timestamp from when the container was CREATED
+func (c *linuxContainer) CreatedTime() time.Time {
+	return c.createdTime
+}
+
 // Config returns the container's configuration
 func (c *linuxContainer) Config() configs.Config {
 	return *c.config
@@ -189,6 +196,9 @@ func (c *linuxContainer) Start(process *Process) error {
 		}
 		return newSystemError(err)
 	}
+	// generate a timestamp indicating when the container was started
+	c.createdTime = time.Now().UTC()
+
 	c.state = &runningState{
 		c: c,
 	}
@@ -1042,6 +1052,7 @@ func (c *linuxContainer) currentState() (*State, error) {
 			Config:               *c.config,
 			InitProcessPid:       pid,
 			InitProcessStartTime: startTime,
+			CreatedTime:          c.createdTime,
 		},
 		CgroupPaths:         c.cgroupManager.GetPaths(),
 		NamespacePaths:      make(map[configs.NamespaceType]string),

libcontainer/factory_linux.go

@@ -201,6 +201,7 @@ func (l *LinuxFactory) Load(id string) (Container, error) {
 		criuPath:      l.CriuPath,
 		cgroupManager: l.NewCgroupsManager(state.Config.Cgroups, state.CgroupPaths),
 		root:          containerRoot,
+		createdTime:   state.CreatedTime,
 	}
 	c.state = &nullState{c: c}
 	if err := c.refreshState(); err != nil {

list.go

@@ -0,0 +1,83 @@
+// +build linux
+
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"text/tabwriter"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/codegangsta/cli"
+)
+
+var listCommand = cli.Command{
+	Name:  "list",
+	Usage: "lists containers started by runc with the given root",
+	Action: func(context *cli.Context) {
+
+		// preload the container factory
+		if factory == nil {
+			err := factoryPreload(context)
+			if err != nil {
+				logrus.Fatal(err)
+				return
+			}
+		}
+
+		// get the list of containers
+		root := context.GlobalString("root")
+		absRoot, err := filepath.Abs(root)
+		if err != nil {
+			logrus.Fatal(err)
+			return
+		}
+		list, err := ioutil.ReadDir(absRoot)
+
+		w := tabwriter.NewWriter(os.Stdout, 12, 1, 3, ' ', 0)
+		fmt.Fprint(w, "ID\tPID\tSTATUS\tCREATED\n")
+
+		// output containers
+		for _, item := range list {
+			switch {
+			case !item.IsDir():
+				// do nothing with misc files in the containers directory
+			case item.IsDir():
+				outputListInfo(item.Name(), w)
+			}
+		}
+
+		if err := w.Flush(); err != nil {
+			logrus.Fatal(err)
+		}
+	},
+}
+
+func outputListInfo(id string, w *tabwriter.Writer) {
+	container, err := factory.Load(id)
+	if err != nil {
+		logrus.Fatal(err)
+		return
+	}
+
+	containerStatus, err := container.Status()
+	if err != nil {
+		logrus.Fatal(err)
+		return
+	}
+
+	state, err := container.State()
+	if err != nil {
+		logrus.Fatal(err)
+		return
+	}
+
+	fmt.Fprintf(w, "%s\t%d\t%s\t%s\n", container.ID(),
+		state.BaseState.InitProcessPid,
+		containerStatus.String(),
+		state.BaseState.CreatedTime.Format(time.RFC3339Nano))
+
+}

main.go

@@ -79,6 +79,7 @@ func main() {
 		pauseCommand,
 		resumeCommand,
 		execCommand,
+		listCommand,
 	}
 	app.Before = func(context *cli.Context) error {
 		if context.GlobalBool("debug") {