consul/connect: trigger update as necessary on connect changes

This PR fixes a long standing bug where submitting jobs with changes
to connect services would not trigger updates as expected. Previously,
service blocks were not considered as sources of destructive updates
since they could be synced with consul non-destructively. With Connect,
task group services that have changes to their connect block or to
the service port should be destructive, since the network plumbing of
the alloc is going to need updating.

Fixes #8596 #7991

Non-destructive half in #7192

nomad/structs/services.go

@@ -696,7 +696,7 @@ func (c *ConsulConnect) Copy() *ConsulConnect {
 	}
 }
 
-// Equals returns true if the structs are recursively equal.
+// Equals returns true if the connect blocks are deeply equal.
 func (c *ConsulConnect) Equals(o *ConsulConnect) bool {
 	if c == nil || o == nil {
 		return c == o
@@ -710,7 +710,9 @@ func (c *ConsulConnect) Equals(o *ConsulConnect) bool {
 		return false
 	}
 
-	// todo(shoenig) task has never been compared, should it be?
+	if !c.SidecarTask.Equals(o.SidecarTask) {
+		return false
+	}
 
 	if !c.Gateway.Equals(o.Gateway) {
 		return false
@@ -864,6 +866,59 @@ type SidecarTask struct {
 	KillSignal string
 }
 
+func (t *SidecarTask) Equals(o *SidecarTask) bool {
+	if t == nil || o == nil {
+		return t == o
+	}
+
+	if t.Name != o.Name {
+		return false
+	}
+
+	if t.Driver != o.Driver {
+		return false
+	}
+
+	if t.User != o.User {
+		return false
+	}
+
+	// config compare
+	if !opaqueMapsEqual(t.Config, o.Config) {
+		return false
+	}
+
+	if !helper.CompareMapStringString(t.Env, o.Env) {
+		return false
+	}
+
+	if !t.Resources.Equals(o.Resources) {
+		return false
+	}
+
+	if !helper.CompareMapStringString(t.Meta, o.Meta) {
+		return false
+	}
+
+	if !helper.CompareTimePtrs(t.KillTimeout, o.KillTimeout) {
+		return false
+	}
+
+	if !t.LogConfig.Equals(o.LogConfig) {
+		return false
+	}
+
+	if !helper.CompareTimePtrs(t.ShutdownDelay, o.ShutdownDelay) {
+		return false
+	}
+
+	if t.KillSignal != o.KillSignal {
+		return false
+	}
+
+	return true
+}
+
 func (t *SidecarTask) Copy() *SidecarTask {
 	if t == nil {
 		return nil

nomad/structs/services_test.go

@@ -349,6 +349,85 @@ func TestSidecarTask_MergeIntoTask(t *testing.T) {
 	require.Exactly(t, expected, task)
 }
 
+func TestSidecarTask_Equals(t *testing.T) {
+	t.Parallel()
+
+	original := &SidecarTask{
+		Name:        "sidecar-task-1",
+		Driver:      "docker",
+		User:        "nobody",
+		Config:      map[string]interface{}{"foo": 1},
+		Env:         map[string]string{"color": "blue"},
+		Resources:   &Resources{MemoryMB: 300},
+		Meta:        map[string]string{"index": "1"},
+		KillTimeout: helper.TimeToPtr(2 * time.Second),
+		LogConfig: &LogConfig{
+			MaxFiles:      2,
+			MaxFileSizeMB: 300,
+		},
+		ShutdownDelay: helper.TimeToPtr(10 * time.Second),
+		KillSignal:    "SIGTERM",
+	}
+
+	t.Run("unmodified", func(t *testing.T) {
+		duplicate := original.Copy()
+		require.True(t, duplicate.Equals(original))
+	})
+
+	type st = SidecarTask
+	type tweaker = func(task *st)
+
+	try := func(t *testing.T, tweak tweaker) {
+		modified := original.Copy()
+		tweak(modified)
+		require.NotEqual(t, original, modified)
+	}
+
+	t.Run("mod name", func(t *testing.T) {
+		try(t, func(s *st) { s.Name = "sidecar-task-2" })
+	})
+
+	t.Run("mod driver", func(t *testing.T) {
+		try(t, func(s *st) { s.Driver = "exec" })
+	})
+
+	t.Run("mod user", func(t *testing.T) {
+		try(t, func(s *st) { s.User = "root" })
+	})
+
+	t.Run("mod config", func(t *testing.T) {
+		try(t, func(s *st) { s.Config = map[string]interface{}{"foo": 2} })
+	})
+
+	t.Run("mod env", func(t *testing.T) {
+		try(t, func(s *st) { s.Env = map[string]string{"color": "red"} })
+	})
+
+	t.Run("mod resources", func(t *testing.T) {
+		try(t, func(s *st) { s.Resources = &Resources{MemoryMB: 200} })
+	})
+
+	t.Run("mod meta", func(t *testing.T) {
+		try(t, func(s *st) { s.Meta = map[string]string{"index": "2"} })
+	})
+
+	t.Run("mod kill timeout", func(t *testing.T) {
+		try(t, func(s *st) { s.KillTimeout = helper.TimeToPtr(3 * time.Second) })
+	})
+
+	t.Run("mod log config", func(t *testing.T) {
+		try(t, func(s *st) { s.LogConfig = &LogConfig{MaxFiles: 3} })
+	})
+
+	t.Run("mod shutdown delay", func(t *testing.T) {
+		try(t, func(s *st) { s.ShutdownDelay = helper.TimeToPtr(20 * time.Second) })
+	})
+
+	t.Run("mod kill signal", func(t *testing.T) {
+		try(t, func(s *st) { s.KillSignal = "SIGHUP" })
+	})
+}
+
 func TestConsulUpstream_upstreamEquals(t *testing.T) {
 	t.Parallel()
 

nomad/structs/structs.go

@@ -6225,6 +6225,22 @@ type LogConfig struct {
 	MaxFileSizeMB int
 }
 
+func (l *LogConfig) Equals(o *LogConfig) bool {
+	if l == nil || o == nil {
+		return l == o
+	}
+
+	if l.MaxFiles != o.MaxFiles {
+		return false
+	}
+
+	if l.MaxFileSizeMB != o.MaxFileSizeMB {
+		return false
+	}
+
+	return true
+}
+
 func (l *LogConfig) Copy() *LogConfig {
 	if l == nil {
 		return nil

nomad/structs/structs_test.go

@@ -2099,6 +2099,38 @@ func TestTask_Validate_LogConfig(t *testing.T) {
 	}
 }
 
+func TestLogConfig_Equals(t *testing.T) {
+	t.Run("both nil", func(t *testing.T) {
+		a := (*LogConfig)(nil)
+		b := (*LogConfig)(nil)
+		require.True(t, a.Equals(b))
+	})
+
+	t.Run("one nil", func(t *testing.T) {
+		a := new(LogConfig)
+		b := (*LogConfig)(nil)
+		require.False(t, a.Equals(b))
+	})
+
+	t.Run("max files", func(t *testing.T) {
+		a := &LogConfig{MaxFiles: 1, MaxFileSizeMB: 200}
+		b := &LogConfig{MaxFiles: 2, MaxFileSizeMB: 200}
+		require.False(t, a.Equals(b))
+	})
+
+	t.Run("max file size", func(t *testing.T) {
+		a := &LogConfig{MaxFiles: 1, MaxFileSizeMB: 100}
+		b := &LogConfig{MaxFiles: 1, MaxFileSizeMB: 200}
+		require.False(t, a.Equals(b))
+	})
+
+	t.Run("same", func(t *testing.T) {
+		a := &LogConfig{MaxFiles: 1, MaxFileSizeMB: 200}
+		b := &LogConfig{MaxFiles: 1, MaxFileSizeMB: 200}
+		require.True(t, a.Equals(b))
+	})
+}
+
 func TestTask_Validate_CSIPluginConfig(t *testing.T) {
 	table := []struct {
 		name        string

scheduler/util.go

@@ -377,6 +377,11 @@ func tasksUpdated(jobA, jobB *structs.Job, taskGroup string) bool {
 		return true
 	}
 
+	// Check connect service(s) updated
+	if connectServiceUpdated(a.Services, b.Services) {
+		return true
+	}
+
 	// Check each task
 	for _, at := range a.Tasks {
 		bt := b.LookupTask(at.Name)
@@ -429,6 +434,78 @@ func tasksUpdated(jobA, jobB *structs.Job, taskGroup string) bool {
 	return false
 }
 
+// connectServiceUpdated returns true if any services with a connect stanza have
+// been changed in such a way that requires a destructive update.
+//
+// Ordinary services can be updated in-place by updating the service definition
+// in Consul. Connect service changes mostly require destroying the task.
+func connectServiceUpdated(servicesA, servicesB []*structs.Service) bool {
+	for _, serviceA := range servicesA {
+		if serviceA.Connect != nil {
+			for _, serviceB := range servicesB {
+				if serviceA.Name == serviceB.Name {
+					if connectUpdated(serviceA.Connect, serviceB.Connect) {
+						return true
+					}
+					// Part of the Connect plumbing is derived from port label,
+					// if that changes we need to destroy the task.
+					if serviceA.PortLabel != serviceB.PortLabel {
+						return true
+					}
+					break
+				}
+			}
+		}
+	}
+	return false
+}
+
+// connectUpdated returns true if the connect block has been updated in a manner
+// that will require a destructive update.
+//
+// Fields that can be updated through consul-sync do not need a destructive
+// update.
+func connectUpdated(connectA, connectB *structs.ConsulConnect) bool {
+	if connectA == nil || connectB == nil {
+		return connectA == connectB
+	}
+
+	if connectA.Native != connectB.Native {
+		return true
+	}
+
+	if !connectA.Gateway.Equals(connectB.Gateway) {
+		return true
+	}
+
+	if !connectA.SidecarTask.Equals(connectB.SidecarTask) {
+		return true
+	}
+
+	// not everything in sidecar_service needs task destruction
+	if connectSidecarServiceUpdated(connectA.SidecarService, connectB.SidecarService) {
+		return true
+	}
+
+	return false
+}
+
+func connectSidecarServiceUpdated(ssA, ssB *structs.ConsulSidecarService) bool {
+	if ssA == nil || ssB == nil {
+		return ssA == ssB
+	}
+
+	if ssA.Port != ssB.Port {
+		return true
+	}
+
+	// sidecar_service.tags handled in-place (registration)
+
+	// sidecar_service.proxy handled in-place (registration + xDS)
+
+	return false
+}
+
 func networkUpdated(netA, netB []*structs.NetworkResource) bool {
 	if len(netA) != len(netB) {
 		return true