podman port

podman port reports the port mappings per container.  it can be used
to report the ports ofa single container or latest container or all
containers.

in the case of a single container, the user can add an option filter for
port and protocol.

Signed-off-by: baude <bbaude@redhat.com>

cmd/podman/main.go

@@ -57,6 +57,7 @@ func main() {
 		mountCommand,
 		pauseCommand,
 		psCommand,
+		portCommand,
 		pullCommand,
 		pushCommand,
 		rmCommand,

cmd/podman/port.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/projectatomic/libpod/libpod"
+	"github.com/urfave/cli"
+)
+
+var (
+	portFlags = []cli.Flag{
+		cli.BoolFlag{
+			Name:  "all, a",
+			Usage: "display port information for all containers",
+		},
+		LatestFlag,
+	}
+	portDescription = `
+   podman port
+
+	List port mappings for the CONTAINER, or lookup the public-facing port that is NAT-ed to the PRIVATE_PORT
+`
+
+	portCommand = cli.Command{
+		Name:        "port",
+		Usage:       "List port mappings or a specific mapping for the container",
+		Description: portDescription,
+		Flags:       portFlags,
+		Action:      portCmd,
+		ArgsUsage:   "CONTAINER-NAME [mapping]",
+	}
+)
+
+func portCmd(c *cli.Context) error {
+	var (
+		userProto, containerName string
+		userPort                 int
+		container                *libpod.Container
+		containers               []*libpod.Container
+	)
+
+	args := c.Args()
+	if err := validateFlags(c, portFlags); err != nil {
+		return err
+	}
+
+	if c.Bool("latest") && c.Bool("all") {
+		return errors.Errorf("the 'all' and 'latest' options cannot be used together")
+	}
+	if c.Bool("all") && len(args) > 0 {
+		return errors.Errorf("no additional arguments can be used with 'all'")
+	}
+	if len(args) == 0 && !c.Bool("latest") && !c.Bool("all") {
+		return errors.Errorf("you must supply a running container name or id")
+	}
+	if !c.Bool("latest") && !c.Bool("all") {
+		containerName = args[0]
+	}
+
+	port := ""
+	if len(args) > 1 && !c.Bool("latest") {
+		port = args[1]
+	}
+	if len(args) == 1 && c.Bool("latest") {
+		port = args[0]
+	}
+	if port != "" {
+		fields := strings.Split(port, "/")
+		// User supplied at least port
+		var err error
+		// User supplied port and protocol
+		if len(fields) == 2 {
+			userProto = fields[1]
+		}
+		if len(fields) >= 1 {
+			p := fields[0]
+			userPort, err = strconv.Atoi(p)
+			if err != nil {
+				return errors.Wrapf(err, "unable to format port")
+			}
+		}
+		// Format is incorrect
+		if len(fields) > 2 || len(fields) < 1 {
+			return errors.Errorf("port formats are port/protocol. '%s' is invalid", port)
+		}
+	}
+
+	runtime, err := getRuntime(c)
+	if err != nil {
+		return errors.Wrapf(err, "could not get runtime")
+	}
+	defer runtime.Shutdown(false)
+
+	if !c.Bool("latest") && !c.Bool("all") {
+		container, err = runtime.LookupContainer(containerName)
+		if err != nil {
+			return errors.Wrapf(err, "unable to find container %s", containerName)
+		}
+		containers = append(containers, container)
+	} else if c.Bool("latest") {
+		container, err = runtime.GetLatestContainer()
+		containers = append(containers, container)
+	} else {
+		containers, err = runtime.GetRunningContainers()
+		if err != nil {
+			return errors.Wrapf(err, "unable to get all containers")
+		}
+	}
+
+	for _, con := range containers {
+		if state, _ := con.State(); state != libpod.ContainerStateRunning {
+			continue
+		}
+		if c.Bool("all") {
+			fmt.Println(con.ID())
+		}
+		// Iterate mappings
+		for _, v := range con.Config().PortMappings {
+			hostIP := v.HostIP
+			// Set host IP to 0.0.0.0 if blank
+			if hostIP == "" {
+				hostIP = "0.0.0.0"
+			}
+			// If not searching by port or port/proto, then dump what we see
+			if port == "" {
+				fmt.Printf("%d/%s -> %s:%d\n", v.ContainerPort, v.Protocol, hostIP, v.HostPort)
+				continue
+			}
+			// We have a match on ports
+			if v.ContainerPort == int32(userPort) {
+				if userProto == "" || userProto == v.Protocol {
+					fmt.Printf("%s:%d", hostIP, v.HostPort)
+					break
+				}
+			} else {
+				return errors.Errorf("No public port '%d' published for %s", userPort, containerName)
+			}
+		}
+	}
+
+	return nil
+}