tr/service_hook: prevent Update from running before Poststart finish

client/allocrunner/taskrunner/service_hook.go

@@ -48,6 +48,10 @@ type serviceHook struct {
 	networks   structs.Networks
 	taskEnv    *taskenv.TaskEnv
 
+	// initialRegistrations tracks if Poststart has completed, initializing
+	// fields required in other lifecycle funcs
+	initialRegistration bool
+
 	// Since Update() may be called concurrently with any other hook all
 	// hook methods must be fully serialized
 	mu sync.Mutex
@@ -87,6 +91,7 @@ func (h *serviceHook) Poststart(ctx context.Context, req *interfaces.TaskPoststa
 	h.driverExec = req.DriverExec
 	h.driverNet = req.DriverNetwork
 	h.taskEnv = req.TaskEnv
+	h.initialRegistration = true
 
 	// Create task services struct with request's driver metadata
 	workloadServices := h.getWorkloadServices()
@@ -97,11 +102,27 @@ func (h *serviceHook) Poststart(ctx context.Context, req *interfaces.TaskPoststa
 func (h *serviceHook) Update(ctx context.Context, req *interfaces.TaskUpdateRequest, _ *interfaces.TaskUpdateResponse) error {
 	h.mu.Lock()
 	defer h.mu.Unlock()
+	if !h.initialRegistration {
+		// no op Consul since initial registration has not finished
+		// only update hook fields
+		return h.updateHookFields(req)
+	}
 
 	// Create old task services struct with request's driver metadata as it
 	// can't change due to Updates
 	oldWorkloadServices := h.getWorkloadServices()
 
+	if err := h.updateHookFields(req); err != nil {
+		return err
+	}
+
+	// Create new task services struct with those new values
+	newWorkloadServices := h.getWorkloadServices()
+
+	return h.consul.UpdateWorkload(oldWorkloadServices, newWorkloadServices)
+}
+
+func (h *serviceHook) updateHookFields(req *interfaces.TaskUpdateRequest) error {
 	// Store new updated values out of request
 	canary := false
 	if req.Alloc.DeploymentStatus != nil {
@@ -125,10 +146,7 @@ func (h *serviceHook) Update(ctx context.Context, req *interfaces.TaskUpdateRequ
 	h.networks = networks
 	h.canary = canary
 
-	// Create new task services struct with those new values
-	newWorkloadServices := h.getWorkloadServices()
-
-	return h.consul.UpdateWorkload(oldWorkloadServices, newWorkloadServices)
+	return nil
 }
 
 func (h *serviceHook) PreKilling(ctx context.Context, req *interfaces.TaskPreKillRequest, resp *interfaces.TaskPreKillResponse) error {
@@ -167,7 +185,7 @@ func (h *serviceHook) deregister() {
 	// destroyed, so remove both variations of the service
 	workloadServices.Canary = !workloadServices.Canary
 	h.consul.RemoveWorkload(workloadServices)
-
+	h.initialRegistration = false
 }
 
 func (h *serviceHook) Stop(ctx context.Context, req *interfaces.TaskStopRequest, resp *interfaces.TaskStopResponse) error {

client/allocrunner/taskrunner/service_hook_test.go

@@ -1,11 +1,54 @@
 package taskrunner
 
 import (
+	"context"
+	"testing"
+
 	"github.com/hashicorp/nomad/client/allocrunner/interfaces"
+	"github.com/hashicorp/nomad/client/consul"
+	"github.com/hashicorp/nomad/helper/testlog"
+	"github.com/hashicorp/nomad/nomad/mock"
+	"github.com/stretchr/testify/require"
 )
 
 // Statically assert the stats hook implements the expected interfaces
 var _ interfaces.TaskPoststartHook = (*serviceHook)(nil)
 var _ interfaces.TaskExitedHook = (*serviceHook)(nil)
 var _ interfaces.TaskPreKillHook = (*serviceHook)(nil)
 var _ interfaces.TaskUpdateHook = (*serviceHook)(nil)
+
+func TestUpdate_beforePoststart(t *testing.T) {
+	alloc := mock.Alloc()
+	logger := testlog.HCLogger(t)
+	c := consul.NewMockConsulServiceClient(t, logger)
+
+	hook := newServiceHook(serviceHookConfig{
+		alloc:  alloc,
+		task:   alloc.LookupTask("web"),
+		consul: c,
+		logger: logger,
+	})
+	require.NoError(t, hook.Update(context.Background(), &interfaces.TaskUpdateRequest{Alloc: alloc}, &interfaces.TaskUpdateResponse{}))
+	require.Len(t, c.GetOps(), 0)
+	require.NoError(t, hook.Poststart(context.Background(), &interfaces.TaskPoststartRequest{}, &interfaces.TaskPoststartResponse{}))
+	require.Len(t, c.GetOps(), 1)
+	require.NoError(t, hook.Update(context.Background(), &interfaces.TaskUpdateRequest{Alloc: alloc}, &interfaces.TaskUpdateResponse{}))
+	require.Len(t, c.GetOps(), 2)
+
+	// When a task exits it could be restarted with new driver info
+	// so Update should again wait on Poststart.
+
+	require.NoError(t, hook.Exited(context.Background(), &interfaces.TaskExitedRequest{}, &interfaces.TaskExitedResponse{}))
+	require.Len(t, c.GetOps(), 4)
+	require.NoError(t, hook.Update(context.Background(), &interfaces.TaskUpdateRequest{Alloc: alloc}, &interfaces.TaskUpdateResponse{}))
+	require.Len(t, c.GetOps(), 4)
+	require.NoError(t, hook.Poststart(context.Background(), &interfaces.TaskPoststartRequest{}, &interfaces.TaskPoststartResponse{}))
+	require.Len(t, c.GetOps(), 5)
+	require.NoError(t, hook.Update(context.Background(), &interfaces.TaskUpdateRequest{Alloc: alloc}, &interfaces.TaskUpdateResponse{}))
+	require.Len(t, c.GetOps(), 6)
+	require.NoError(t, hook.PreKilling(context.Background(), &interfaces.TaskPreKillRequest{}, &interfaces.TaskPreKillResponse{}))
+	require.Len(t, c.GetOps(), 8)
+	require.NoError(t, hook.Update(context.Background(), &interfaces.TaskUpdateRequest{Alloc: alloc}, &interfaces.TaskUpdateResponse{}))
+	require.Len(t, c.GetOps(), 8)
+
+}