Enable port bindings

Set up nbetworking ports for the following use cases:

* bind the same port between host and container
* bind a specific host port to a different container port
* bind a random host port to a specific container port

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

Closes: #214
Approved by: baude

2 files changed, 99 insertions, 6 deletions

diff --git a/cmd/podman/create.go b/cmd/podman/create.go
index 55425638f..28bd0a60e 100644
--- a/cmd/podman/create.go
+++ b/cmd/podman/create.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"net"
 	"os"
 	"strconv"
 	"strings"
@@ -287,15 +288,25 @@ func parseSecurityOpt(config *createConfig, securityOpts []string) error {
 	return err
 }
 
+// isPortInPortBindings determines if an exposed host port is in user
+// provided ports
+func isPortInPortBindings(pb map[nat.Port][]nat.PortBinding, port nat.Port) bool {
+	var hostPorts []string
+	for _, i := range pb {
+		hostPorts = append(hostPorts, i[0].HostPort)
+	}
+	return libpod.StringInSlice(port.Port(), hostPorts)
+}
+
 func exposedPorts(c *cli.Context, imageExposedPorts map[string]struct{}) (map[nat.Port]struct{}, map[nat.Port][]nat.PortBinding, error) {
 	// TODO Handle exposed ports from image
 	// Currently ignoring imageExposedPorts
-
-	ports, portBindings, err := nat.ParsePortSpecs(c.StringSlice("publish"))
+	var ports map[nat.Port]struct{}
+	ports = make(map[nat.Port]struct{})
+	_, portBindings, err := nat.ParsePortSpecs(c.StringSlice("publish"))
 	if err != nil {
 		return nil, nil, err
 	}
-
 	for _, e := range c.StringSlice("expose") {
 		// Merge in exposed ports to the map of published ports
 		if strings.Contains(e, ":") {
@@ -314,6 +325,28 @@ func exposedPorts(c *cli.Context, imageExposedPorts map[string]struct{}) (map[na
 			if err != nil {
 				return nil, nil, err
 			}
+			// check if the port in question is already being used
+			if isPortInPortBindings(portBindings, p) {
+				return nil, nil, errors.Errorf("host port %s already used in --publish option", p.Port())
+			}
+
+			if c.Bool("publish-all") {
+				l, err := net.Listen("tcp", ":0")
+				if err != nil {
+					return nil, nil, errors.Wrapf(err, "unable to get free port")
+				}
+				_, randomPort, err := net.SplitHostPort(l.Addr().String())
+				if err != nil {
+					return nil, nil, errors.Wrapf(err, "unable to determine free port")
+				}
+				rp, err := strconv.Atoi(randomPort)
+				if err != nil {
+					return nil, nil, errors.Wrapf(err, "unable to convert random port to int")
+				}
+				logrus.Debug(fmt.Sprintf("Using random host port %s with container port %d", randomPort, p.Int()))
+				portBindings[p] = CreatePortBinding(rp, "")
+				continue
+			}
 			if _, exists := ports[p]; !exists {
 				ports[p] = struct{}{}
 			}
@@ -669,3 +702,12 @@ func parseCreateOpts(c *cli.Context, runtime *libpod.Runtime, imageName string,
 	}
 	return config, nil
 }
+
+//CreatePortBinding takes port (int) and IP (string) and creates an array of portbinding structs
+func CreatePortBinding(hostPort int, hostIP string) []nat.PortBinding {
+	pb := nat.PortBinding{
+		HostPort: strconv.Itoa(hostPort),
+	}
+	pb.HostIP = hostIP
+	return []nat.PortBinding{pb}
+}
diff --git a/cmd/podman/spec.go b/cmd/podman/spec.go
index 152d1740c..cb9efdcb2 100644
--- a/cmd/podman/spec.go
+++ b/cmd/podman/spec.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"io/ioutil"
+	"strconv"
 	"strings"
 
 	"github.com/cri-o/ocicni/pkg/ocicni"
@@ -543,6 +544,8 @@ func (c *createConfig) GetTmpfsMounts() []spec.Mount {
 
 func (c *createConfig) GetContainerCreateOptions() ([]libpod.CtrCreateOption, error) {
 	var options []libpod.CtrCreateOption
+	var portBindings []ocicni.PortMapping
+	var err error
 
 	// Uncomment after talking to mheon about unimplemented funcs
 	// options = append(options, libpod.WithLabels(c.labels))
@@ -554,17 +557,25 @@ func (c *createConfig) GetContainerCreateOptions() ([]libpod.CtrCreateOption, er
 		logrus.Debugf("appending name %s", c.Name)
 		options = append(options, libpod.WithName(c.Name))
 	}
-	// TODO parse ports into libpod format and include
+
+	// TODO deal with ports defined in image metadata
+	if len(c.PortBindings) > 0 || len(c.ExposedPorts) > 0 {
+		portBindings, err = c.CreatePortBindings()
+		if err != nil {
+			return nil, errors.Wrapf(err, "unable to create port bindings")
+		}
+	}
+
 	if c.NetMode.IsContainer() {
 		connectedCtr, err := c.Runtime.LookupContainer(c.NetMode.ConnectedContainer())
 		if err != nil {
 			return nil, errors.Wrapf(err, "container %q not found", c.NetMode.ConnectedContainer())
 		}
-
 		options = append(options, libpod.WithNetNSFrom(connectedCtr))
 	} else if !c.NetMode.IsHost() {
-		options = append(options, libpod.WithNetNS([]ocicni.PortMapping{}))
+		options = append(options, libpod.WithNetNS(portBindings))
 	}
+
 	if c.PidMode.IsContainer() {
 		connectedCtr, err := c.Runtime.LookupContainer(c.PidMode.Container())
 		if err != nil {
@@ -622,3 +633,43 @@ func makeThrottleArray(throttleInput []string) ([]spec.LinuxThrottleDevice, erro
 	}
 	return ltds, nil
 }
+
+// CreatePortBindings iterates ports mappings and exposed ports into a format CNI understands
+func (c *createConfig) CreatePortBindings() ([]ocicni.PortMapping, error) {
+	var portBindings []ocicni.PortMapping
+	for containerPb, hostPb := range c.PortBindings {
+		var pm ocicni.PortMapping
+		pm.ContainerPort = int32(containerPb.Int())
+		for _, i := range hostPb {
+			var hostPort int
+			var err error
+			pm.HostIP = i.HostIP
+			if i.HostPort == "" {
+				hostPort = containerPb.Int()
+			} else {
+				hostPort, err = strconv.Atoi(i.HostPort)
+				if err != nil {
+					return nil, errors.Wrapf(err, "unable to convert host port to integer")
+				}
+			}
+
+			pm.HostPort = int32(hostPort)
+			// CNI requires us to make both udp and tcp structs
+			pm.Protocol = "udp"
+			portBindings = append(portBindings, pm)
+			pm.Protocol = "tcp"
+			portBindings = append(portBindings, pm)
+		}
+	}
+	for j := range c.ExposedPorts {
+		var expose ocicni.PortMapping
+		expose.HostPort = int32(j.Int())
+		expose.ContainerPort = int32(j.Int())
+		// CNI requires us to make both udp and tcp structs
+		expose.Protocol = "udp"
+		portBindings = append(portBindings, expose)
+		expose.Protocol = "tcp"
+		portBindings = append(portBindings, expose)
+	}
+	return portBindings, nil
+}