Support EXPOSE with port ranges

Fixes issue containers#12293. EXPOSE directive in images should mirror the --expose
parameter. Specifically `EXPOSE 20000-20100/tcp` should work the same
as `--expose 20000-20100/tcp`

Signed-off-by: Colin Bendell <colin@bendell.ca>

pkg/specgen/generate/ports.go

@@ -5,14 +5,14 @@ import (
 	"fmt"
 	"net"
 	"sort"
-	"strconv"
 	"strings"
 
 	"github.com/containers/common/libimage"
 	"github.com/containers/podman/v3/libpod/network/types"
 	"github.com/containers/podman/v3/utils"
 
 	"github.com/containers/podman/v3/pkg/specgen"
+	"github.com/containers/podman/v3/pkg/specgenutil"
 	"github.com/containers/podman/v3/pkg/util"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -410,31 +410,13 @@ func checkProtocol(protocol string, allowSCTP bool) ([]string, error) {
 }
 
 func GenExposedPorts(exposedPorts map[string]struct{}) (map[uint16]string, error) {
-	expose := make(map[uint16]string, len(exposedPorts))
-	for imgExpose := range exposedPorts {
-		// Expose format is portNumber[/protocol]
-		splitExpose := strings.SplitN(imgExpose, "/", 2)
-		num, err := strconv.Atoi(splitExpose[0])
-		if err != nil {
-			return nil, errors.Wrapf(err, "unable to convert image EXPOSE statement %q to port number", imgExpose)
-		}
-		if num > 65535 || num < 1 {
-			return nil, errors.Errorf("%d from image EXPOSE statement %q is not a valid port number", num, imgExpose)
-		}
-
-		// No need to validate protocol, we'll do it later.
-		newProto := "tcp"
-		if len(splitExpose) == 2 {
-			newProto = splitExpose[1]
-		}
-
-		proto := expose[uint16(num)]
-		if len(proto) > 1 {
-			proto = proto + "," + newProto
-		} else {
-			proto = newProto
-		}
-		expose[uint16(num)] = proto
+	expose := make([]string, 0, len(exposedPorts))
+	for e := range exposedPorts {
+		expose = append(expose, e)
+	}
+	toReturn, err := specgenutil.CreateExpose(expose)
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to convert image EXPOSE")
 	}
-	return expose, nil
+	return toReturn, nil
 }

pkg/specgenutil/specgen.go

@@ -314,7 +314,7 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *entities.ContainerCreateOptions
 		s.Pod = podID
 	}
 
-	expose, err := createExpose(c.Expose)
+	expose, err := CreateExpose(c.Expose)
 	if err != nil {
 		return err
 	}

pkg/specgenutil/util.go

@@ -53,11 +53,11 @@ func ParseFilters(filter []string) (map[string][]string, error) {
 	return filters, nil
 }
 
-// createExpose parses user-provided exposed port definitions and converts them
+// CreateExpose parses user-provided exposed port definitions and converts them
 // into SpecGen format.
 // TODO: The SpecGen format should really handle ranges more sanely - we could
 // be massively inflating what is sent over the wire with a large range.
-func createExpose(expose []string) (map[uint16]string, error) {
+func CreateExpose(expose []string) (map[uint16]string, error) {
 	toReturn := make(map[uint16]string)
 
 	for _, e := range expose {