Idempotent service update --publish-add

This fix tries to address the issue raised in 25375 where
`service update --publish-add` returns an error if the exact
same value is repeated (idempotent).

This fix use a map to filter out repeated port configs so
that `--publish-add` does not error out.

An integration test has been added.

This fix fixes 25375.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

api/client/service/update.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"fmt"
+	"sort"
 	"strings"
 	"time"
 
@@ -216,7 +217,9 @@ func updateService(flags *pflag.FlagSet, spec *swarm.ServiceSpec) error {
 		if spec.EndpointSpec == nil {
 			spec.EndpointSpec = &swarm.EndpointSpec{}
 		}
-		updatePorts(flags, &spec.EndpointSpec.Ports)
+		if err := updatePorts(flags, &spec.EndpointSpec.Ports); err != nil {
+			return err
+		}
 	}
 
 	if err := updateLogDriver(flags, &spec.TaskTemplate); err != nil {
@@ -369,23 +372,54 @@ func updateMounts(flags *pflag.FlagSet, mounts *[]swarm.Mount) {
 	*mounts = newMounts
 }
 
-func updatePorts(flags *pflag.FlagSet, portConfig *[]swarm.PortConfig) {
+type byPortConfig []swarm.PortConfig
+
+func (r byPortConfig) Len() int      { return len(r) }
+func (r byPortConfig) Swap(i, j int) { r[i], r[j] = r[j], r[i] }
+func (r byPortConfig) Less(i, j int) bool {
+	// We convert PortConfig into `port/protocol`, e.g., `80/tcp`
+	// In updatePorts we already filter out with map so there is duplicate entries
+	return portConfigToString(&r[i]) < portConfigToString(&r[j])
+}
+
+func portConfigToString(portConfig *swarm.PortConfig) string {
+	protocol := portConfig.Protocol
+	if protocol == "" {
+		protocol = "tcp"
+	}
+	return fmt.Sprintf("%v/%s", portConfig.PublishedPort, protocol)
+}
+
+func updatePorts(flags *pflag.FlagSet, portConfig *[]swarm.PortConfig) error {
+	// The key of the map is `port/protocol`, e.g., `80/tcp`
+	portSet := map[string]swarm.PortConfig{}
+	// Check to see if there are any conflict in flags.
 	if flags.Changed(flagPublishAdd) {
 		values := flags.Lookup(flagPublishAdd).Value.(*opts.ListOpts).GetAll()
 		ports, portBindings, _ := nat.ParsePortSpecs(values)
 
 		for port := range ports {
-			*portConfig = append(*portConfig, convertPortToPortConfig(port, portBindings)...)
+			newConfigs := convertPortToPortConfig(port, portBindings)
+			for _, entry := range newConfigs {
+				if v, ok := portSet[portConfigToString(&entry)]; ok && v != entry {
+					return fmt.Errorf("conflicting port mapping between %v:%v/%s and %v:%v/%s", entry.PublishedPort, entry.TargetPort, entry.Protocol, v.PublishedPort, v.TargetPort, v.Protocol)
+				}
+				portSet[portConfigToString(&entry)] = entry
+			}
 		}
 	}
 
-	if !flags.Changed(flagPublishRemove) {
-		return
+	// Override previous PortConfig in service if there is any duplicate
+	for _, entry := range *portConfig {
+		if _, ok := portSet[portConfigToString(&entry)]; !ok {
+			portSet[portConfigToString(&entry)] = entry
+		}
 	}
+
 	toRemove := flags.Lookup(flagPublishRemove).Value.(*opts.ListOpts).GetAll()
 	newPorts := []swarm.PortConfig{}
 portLoop:
-	for _, port := range *portConfig {
+	for _, port := range portSet {
 		for _, rawTargetPort := range toRemove {
 			targetPort := nat.Port(rawTargetPort)
 			if equalPort(targetPort, port) {
@@ -394,7 +428,10 @@ portLoop:
 		}
 		newPorts = append(newPorts, port)
 	}
+	// Sort the PortConfig to avoid unnecessary updates
+	sort.Sort(byPortConfig(newPorts))
 	*portConfig = newPorts
+	return nil
 }
 
 func equalPort(targetPort nat.Port, port swarm.PortConfig) bool {

api/client/service/update_test.go

@@ -141,8 +141,56 @@ func TestUpdatePorts(t *testing.T) {
 		{TargetPort: 555},
 	}
 
-	updatePorts(flags, &portConfigs)
+	err := updatePorts(flags, &portConfigs)
+	assert.Equal(t, err, nil)
 	assert.Equal(t, len(portConfigs), 2)
-	assert.Equal(t, portConfigs[0].TargetPort, uint32(555))
-	assert.Equal(t, portConfigs[1].TargetPort, uint32(1000))
+	// Do a sort to have the order (might have changed by map)
+	targetPorts := []int{int(portConfigs[0].TargetPort), int(portConfigs[1].TargetPort)}
+	sort.Ints(targetPorts)
+	assert.Equal(t, targetPorts[0], 555)
+	assert.Equal(t, targetPorts[1], 1000)
+}
+
+func TestUpdatePortsDuplicateEntries(t *testing.T) {
+	// Test case for #25375
+	flags := newUpdateCommand(nil).Flags()
+	flags.Set("publish-add", "80:80")
+
+	portConfigs := []swarm.PortConfig{
+		{TargetPort: 80, PublishedPort: 80},
+	}
+
+	err := updatePorts(flags, &portConfigs)
+	assert.Equal(t, err, nil)
+	assert.Equal(t, len(portConfigs), 1)
+	assert.Equal(t, portConfigs[0].TargetPort, uint32(80))
+}
+
+func TestUpdatePortsDuplicateKeys(t *testing.T) {
+	// Test case for #25375
+	flags := newUpdateCommand(nil).Flags()
+	flags.Set("publish-add", "80:20")
+
+	portConfigs := []swarm.PortConfig{
+		{TargetPort: 80, PublishedPort: 80},
+	}
+
+	err := updatePorts(flags, &portConfigs)
+	assert.Equal(t, err, nil)
+	assert.Equal(t, len(portConfigs), 1)
+	assert.Equal(t, portConfigs[0].TargetPort, uint32(20))
+}
+
+func TestUpdatePortsConflictingFlags(t *testing.T) {
+	// Test case for #25375
+	flags := newUpdateCommand(nil).Flags()
+	flags.Set("publish-add", "80:80")
+	flags.Set("publish-add", "80:20")
+
+	portConfigs := []swarm.PortConfig{
+		{TargetPort: 80, PublishedPort: 80},
+	}
+
+	err := updatePorts(flags, &portConfigs)
+	assert.Error(t, err, "conflicting port mapping")
 }

integration-cli/docker_cli_swarm_test.go

@@ -194,3 +194,29 @@ func (s *DockerSwarmSuite) TestSwarmNodeTaskListFilter(c *check.C) {
 	c.Assert(out, checker.Not(checker.Contains), name+".2")
 	c.Assert(out, checker.Not(checker.Contains), name+".3")
 }
+
+// Test case for #25375
+func (s *DockerSwarmSuite) TestSwarmPublishAdd(c *check.C) {
+	d := s.AddDaemon(c, true, true)
+
+	name := "top"
+	out, err := d.Cmd("service", "create", "--name", name, "--label", "x=y", "busybox", "top")
+	c.Assert(err, checker.IsNil)
+	c.Assert(strings.TrimSpace(out), checker.Not(checker.Equals), "")
+
+	out, err = d.Cmd("service", "update", "--publish-add", "80:80", name)
+	c.Assert(err, checker.IsNil)
+
+	out, err = d.Cmd("service", "update", "--publish-add", "80:80", name)
+	c.Assert(err, checker.IsNil)
+
+	out, err = d.Cmd("service", "update", "--publish-add", "80:80", "--publish-add", "80:20", name)
+	c.Assert(err, checker.NotNil)
+
+	out, err = d.Cmd("service", "update", "--publish-add", "80:20", name)
+	c.Assert(err, checker.IsNil)
+
+	out, err = d.Cmd("service", "inspect", "--format", "{{ .Spec.EndpointSpec.Ports }}", name)
+	c.Assert(err, checker.IsNil)
+	c.Assert(strings.TrimSpace(out), checker.Equals, "[{ tcp 20 80}]")
+}