Add support for consul EnableTagOverride

api/tasks.go

@@ -364,14 +364,15 @@ type ServiceCheck struct {
 
 // The Service model represents a Consul service definition
 type Service struct {
-	Id           string
-	Name         string
-	Tags         []string
-	CanaryTags   []string `mapstructure:"canary_tags"`
-	PortLabel    string   `mapstructure:"port"`
-	AddressMode  string   `mapstructure:"address_mode"`
-	Checks       []ServiceCheck
-	CheckRestart *CheckRestart `mapstructure:"check_restart"`
+	Id                string
+	Name              string
+	Tags              []string
+	CanaryTags        []string `mapstructure:"canary_tags"`
+	PortLabel         string   `mapstructure:"port"`
+	AddressMode       string   `mapstructure:"address_mode"`
+	Checks            []ServiceCheck
+	CheckRestart      *CheckRestart `mapstructure:"check_restart"`
+	EnableTagOverride bool
 }
 
 func (s *Service) Canonicalize(t *Task, tg *TaskGroup, job *Job) {

command/agent/consul/client.go

@@ -94,9 +94,17 @@ func agentServiceUpdateRequired(reg *api.AgentServiceRegistration, svc *api.Agen
 		reg.Port == svc.Port &&
 		reg.Address == svc.Address &&
 		reg.Name == svc.Service &&
+		reg.EnableTagOverride == svc.EnableTagOverride &&
 		reflect.DeepEqual(reg.Tags, svc.Tags))
 }
 
+// Replace with Consul tags
+func replaceServiceTagsWithConsulTags(reg *api.AgentServiceRegistration, svc *api.AgentService) {
+	if svc != nil {
+		copy(reg.Tags, svc.Tags)
+	}
+}
+
 // operations are submitted to the main loop via commit() for synchronizing
 // with Consul.
 type operations struct {
@@ -485,6 +493,11 @@ func (c *ServiceClient) sync() error {
 		existingSvc, ok := consulServices[id]
 
 		if ok {
+			if locals.EnableTagOverride {
+				// if EnableTagOverride is set, then we want to keep the tags updated by external services
+				replaceServiceTagsWithConsulTags(locals, existingSvc)
+			}
+
 			// There is an existing registration of this service in Consul, so here
 			// we validate to see if the service has been invalidated to see if it
 			// should be updated.
@@ -597,6 +610,7 @@ func (c *ServiceClient) RegisterAgent(role string, services []*structs.Service)
 			Meta: map[string]string{
 				"external-source": "nomad",
 			},
+			EnableTagOverride: service.EnableTagOverride,
 		}
 		ops.regServices = append(ops.regServices, serviceReg)
 
@@ -695,6 +709,7 @@ func (c *ServiceClient) serviceRegs(ops *operations, service *structs.Service, t
 		Meta: map[string]string{
 			"external-source": "nomad",
 		},
+		EnableTagOverride: service.EnableTagOverride,
 	}
 	ops.regServices = append(ops.regServices, serviceReg)
 
@@ -1110,9 +1125,9 @@ func makeAgentServiceID(role string, service *structs.Service) string {
 // Consul. All structs.Service fields are included in the ID's hash except
 // Checks. This allows updates to merely compare IDs.
 //
-//	Example Service ID: _nomad-task-b4e61df9-b095-d64e-f241-23860da1375f-redis-http
+//	Example Service ID: _nomad-task-b4e61df9-b095-d64e-f241-23860da1375f-redis-http-false
 func makeTaskServiceID(allocID, taskName string, service *structs.Service, canary bool) string {
-	return fmt.Sprintf("%s%s-%s-%s", nomadTaskPrefix, allocID, taskName, service.Name)
+	return fmt.Sprintf("%s%s-%s-%s-%t", nomadTaskPrefix, allocID, taskName, service.Name, service.EnableTagOverride)
 }
 
 // makeCheckID creates a unique ID for a check.

command/agent/consul/unit_test.go

@@ -163,6 +163,79 @@ func TestConsul_ChangeTags(t *testing.T) {
 	}
 }
 
+func TestConsul_ChangeEnableTagOverride(t *testing.T) {
+	ctx := setupFake(t)
+	require := require.New(t)
+
+	require.NoError(ctx.ServiceClient.RegisterTask(ctx.Task))
+	require.NoError(ctx.syncOnce())
+	require.Equal(1, len(ctx.FakeConsul.services), "Expected 1 service to be registered with Consul")
+
+	// Validate the alloc registration
+	reg1, err := ctx.ServiceClient.AllocRegistrations(ctx.Task.AllocID)
+	require.NoError(err)
+	require.NotNil(reg1, "Unexpected nil alloc registration")
+	require.Equal(1, reg1.NumServices())
+
+	for _, v := range ctx.FakeConsul.services {
+		require.Equal(false, v.EnableTagOverride)
+	}
+
+	// Update the task definition
+	origTask := ctx.Task.Copy()
+	ctx.Task.Services[0].EnableTagOverride = true
+
+	// Register and sync the update
+	require.NoError(ctx.ServiceClient.UpdateTask(origTask, ctx.Task))
+	require.NoError(ctx.syncOnce())
+	require.Equal(1, len(ctx.FakeConsul.services), "Expected 1 service to be registered with Consul")
+
+	// Validate the metadata changed
+	for _, v := range ctx.FakeConsul.services {
+		require.Equal(true, v.EnableTagOverride)
+	}
+}
+
+func TestConsul_ChangeTagsExternally(t *testing.T) {
+	ctx := setupFake(t)
+	require := require.New(t)
+
+	//EnableTagOverride is enabled
+	ctx.Task.Services[0].EnableTagOverride = true
+
+	require.NoError(ctx.ServiceClient.RegisterTask(ctx.Task))
+	require.NoError(ctx.syncOnce())
+	require.Equal(1, len(ctx.FakeConsul.services), "Expected 1 service to be registered with Consul")
+
+	// Validate the alloc registration
+	reg1, err := ctx.ServiceClient.AllocRegistrations(ctx.Task.AllocID)
+	require.NoError(err)
+	require.NotNil(reg1, "Unexpected nil alloc registration")
+	require.Equal(1, reg1.NumServices())
+	require.Equal(0, reg1.NumChecks())
+
+	newTags := []string{"new", "tag"}
+	for _, v := range ctx.FakeConsul.services {
+		//update the tags in Consul directly
+		v.Tags = newTags
+	}
+
+	// sync the update
+	origTask := ctx.Task.Copy()
+	require.NoError(ctx.ServiceClient.UpdateTask(origTask, ctx.Task))
+	require.NoError(ctx.syncOnce())
+	require.Equal(1, len(ctx.FakeConsul.services), "Expected 1 service to be registered with Consul")
+
+	// Validate the metadata changed
+	for _, v := range ctx.FakeConsul.services {
+		require.Equal(newTags, v.Tags, ctx.Task.Services[0].Tags)
+	}
+
+	for _, v := range ctx.ServiceClient.services {
+		require.Equal(newTags, v.Tags, ctx.Task.Services[0].Tags)
+	}
+}
+
 // TestConsul_ChangePorts asserts that changing the ports on a service updates
 // it in Consul. Pre-0.7.1 ports were not part of the service ID and this was a
 // slightly different code path than changing tags.
@@ -1296,6 +1369,36 @@ func TestConsul_CanaryTags_NoTags(t *testing.T) {
 	require.Len(ctx.FakeConsul.services, 0)
 }
 
+// TestConsul_EnableTagOverrideEnabled asserts EnableTagOverride is set when EnableTagOverride=true
+func TestConsul_EnableTagOverrideEnabled(t *testing.T) {
+	t.Parallel()
+	require := require.New(t)
+	ctx := setupFake(t)
+
+	ctx.Task.Services[0].EnableTagOverride = true
+
+	require.NoError(ctx.ServiceClient.RegisterTask(ctx.Task))
+	require.NoError(ctx.syncOnce())
+	require.Len(ctx.FakeConsul.services, 1)
+	for _, service := range ctx.FakeConsul.services {
+		require.Equal(true, service.EnableTagOverride)
+	}
+}
+
+// TestConsul_EnableTagOverrideIsDisabledByDefault asserts EnableTagOverride is disabled by default
+func TestConsul_EnableTagOverrideIsDisabledByDefault(t *testing.T) {
+	t.Parallel()
+	require := require.New(t)
+	ctx := setupFake(t)
+
+	require.NoError(ctx.ServiceClient.RegisterTask(ctx.Task))
+	require.NoError(ctx.syncOnce())
+	require.Len(ctx.FakeConsul.services, 1)
+	for _, service := range ctx.FakeConsul.services {
+		require.Equal(false, service.EnableTagOverride)
+	}
+}
+
 // TestConsul_PeriodicSync asserts that Nomad periodically reconciles with
 // Consul.
 func TestConsul_PeriodicSync(t *testing.T) {

command/agent/job_endpoint.go

@@ -763,11 +763,12 @@ func ApiTaskToStructsTask(apiTask *api.Task, structsTask *structs.Task) {
 		structsTask.Services = make([]*structs.Service, l)
 		for i, service := range apiTask.Services {
 			structsTask.Services[i] = &structs.Service{
-				Name:        service.Name,
-				PortLabel:   service.PortLabel,
-				Tags:        service.Tags,
-				CanaryTags:  service.CanaryTags,
-				AddressMode: service.AddressMode,
+				Name:              service.Name,
+				PortLabel:         service.PortLabel,
+				Tags:              service.Tags,
+				CanaryTags:        service.CanaryTags,
+				AddressMode:       service.AddressMode,
+				EnableTagOverride: service.EnableTagOverride,
 			}
 
 			if l := len(service.Checks); l != 0 {

command/agent/job_endpoint_test.go

@@ -1398,6 +1398,11 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 									},
 								},
 							},
+							{
+								Id:                "id_serviceB",
+								Name:              "serviceB",
+								EnableTagOverride: true,
+							},
 						},
 						Resources: &api.Resources{
 							CPU:      helper.IntToPtr(100),
@@ -1698,6 +1703,11 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 									},
 								},
 							},
+							{
+								Name:              "serviceB",
+								EnableTagOverride: true,
+								AddressMode:       "auto",
+							},
 						},
 						Resources: &structs.Resources{
 							CPU:      100,

nomad/structs/diff_test.go

@@ -3949,6 +3949,12 @@ func TestTaskDiff(t *testing.T) {
 						Type: DiffTypeAdded,
 						Name: "Service",
 						Fields: []*FieldDiff{
+							{
+								Type: DiffTypeAdded,
+								Name: "EnableTagOverride",
+								Old:  "",
+								New:  "false",
+							},
 							{
 								Type: DiffTypeAdded,
 								Name: "Name",
@@ -3967,6 +3973,12 @@ func TestTaskDiff(t *testing.T) {
 						Type: DiffTypeDeleted,
 						Name: "Service",
 						Fields: []*FieldDiff{
+							{
+								Type: DiffTypeDeleted,
+								Name: "EnableTagOverride",
+								Old:  "false",
+								New:  "",
+							},
 							{
 								Type: DiffTypeDeleted,
 								Name: "Name",
@@ -4016,6 +4028,12 @@ func TestTaskDiff(t *testing.T) {
 								Name: "AddressMode",
 								New:  "driver",
 							},
+							{
+								Type: DiffTypeNone,
+								Name: "EnableTagOverride",
+								Old:  "false",
+								New:  "false",
+							},
 							{
 								Type: DiffTypeNone,
 								Name: "Name",
@@ -4113,6 +4131,12 @@ func TestTaskDiff(t *testing.T) {
 								Type: DiffTypeNone,
 								Name: "AddressMode",
 							},
+							{
+								Type: DiffTypeNone,
+								Name: "EnableTagOverride",
+								Old:  "false",
+								New:  "false",
+							},
 							{
 								Type: DiffTypeNone,
 								Name: "Name",
@@ -4447,6 +4471,12 @@ func TestTaskDiff(t *testing.T) {
 								Old:  "",
 								New:  "",
 							},
+							{
+								Type: DiffTypeNone,
+								Name: "EnableTagOverride",
+								Old:  "false",
+								New:  "false",
+							},
 							{
 								Type: DiffTypeNone,
 								Name: "Name",

nomad/structs/structs.go

@@ -5113,9 +5113,10 @@ type Service struct {
 	// this service.
 	AddressMode string
 
-	Tags       []string        // List of tags for the service
-	CanaryTags []string        // List of tags for the service when it is a canary
-	Checks     []*ServiceCheck // List of checks associated with the service
+	Tags              []string        // List of tags for the service
+	CanaryTags        []string        // List of tags for the service when it is a canary
+	Checks            []*ServiceCheck // List of checks associated with the service
+	EnableTagOverride bool            // Allow external agents to change the tags for a service
 }
 
 func (s *Service) Copy() *Service {