Exemple #1
0
// registerService registers a Service with Consul
func (c *ConsulService) registerService(service *structs.Service, task *structs.Task, alloc *structs.Allocation) error {
	var mErr multierror.Error
	host, port := task.FindHostAndPortFor(service.PortLabel)
	if host == "" || port == 0 {
		return fmt.Errorf("consul: the port:%q marked for registration of service: %q couldn't be found", service.PortLabel, service.Name)
	}
	serviceID := alloc.Services[service.Name]
	c.serviceStates[serviceID] = service.Hash()

	asr := &consul.AgentServiceRegistration{
		ID:      serviceID,
		Name:    service.Name,
		Tags:    service.Tags,
		Port:    port,
		Address: host,
	}

	if err := c.client.ServiceRegister(asr); err != nil {
		c.printLogMessage("[DEBUG] consul: error while registering service %v with consul: %v", service.Name, err)
		mErr.Errors = append(mErr.Errors, err)
	}
	for _, check := range service.Checks {
		cr := c.makeCheck(serviceID, check, host, port)
		if err := c.registerCheck(cr); err != nil {
			c.printLogMessage("[DEBUG] consul: error while registering check %v with consul: %v", check.Name, err)
			mErr.Errors = append(mErr.Errors, err)
		}

	}
	return mErr.ErrorOrNil()
}
Exemple #2
0
// registerService registers a Service with Consul
func (c *ConsulService) registerService(service *structs.Service, task *structs.Task, allocID string) error {
	var mErr multierror.Error
	service.Id = fmt.Sprintf("%s-%s", allocID, service.Name)
	host, port := task.FindHostAndPortFor(service.PortLabel)
	if host == "" || port == 0 {
		return fmt.Errorf("consul: The port:%s marked for registration of service: %s couldn't be found", service.PortLabel, service.Name)
	}
	c.serviceStates[service.Id] = service.Hash()

	asr := &consul.AgentServiceRegistration{
		ID:      service.Id,
		Name:    service.Name,
		Tags:    service.Tags,
		Port:    port,
		Address: host,
	}

	if err := c.client.ServiceRegister(asr); err != nil {
		c.logger.Printf("[DEBUG] consul: Error while registering service %v with Consul: %v", service.Name, err)
		mErr.Errors = append(mErr.Errors, err)
	}
	for _, check := range service.Checks {
		cr := c.makeCheck(service, check, host, port)
		if err := c.registerCheck(cr); err != nil {
			c.logger.Printf("[ERROR] consul: Error while registerting check %v with Consul: %v", check.Name, err)
			mErr.Errors = append(mErr.Errors, err)
		}

	}
	return mErr.ErrorOrNil()
}
Exemple #3
0
func TestConsul_Services_Deleted_From_Task(t *testing.T) {
	c := newConsulService()
	task := structs.Task{
		Name: "redis",
		Services: []*structs.Service{
			&structs.Service{
				Name:      "example-cache-redis",
				Tags:      []string{"global"},
				PortLabel: "db",
			},
		},
		Resources: &structs.Resources{
			Networks: []*structs.NetworkResource{
				{
					IP:           "10.10.0.1",
					DynamicPorts: []structs.Port{{"db", 20413}},
				},
			},
		},
	}
	c.Register(&task, "1")
	if len(c.serviceStates) != 1 {
		t.Fatalf("Expected tracked services: %v, Actual: %v", 1, len(c.serviceStates))
	}
	task.Services = []*structs.Service{}

	c.performSync()
	if len(c.serviceStates) != 0 {
		t.Fatalf("Expected tracked services: %v, Actual: %v", 0, len(c.serviceStates))
	}
}
Exemple #4
0
// handleUpdate takes an updated allocation and updates internal state to
// reflect the new config for the task.
func (r *TaskRunner) handleUpdate(update *structs.Allocation) error {
	// Extract the task group from the alloc.
	tg := update.Job.LookupTaskGroup(update.TaskGroup)
	if tg == nil {
		return fmt.Errorf("alloc '%s' missing task group '%s'", update.ID, update.TaskGroup)
	}

	// Extract the task.
	var updatedTask *structs.Task
	for _, t := range tg.Tasks {
		if t.Name == r.task.Name {
			updatedTask = t
		}
	}
	if updatedTask == nil {
		return fmt.Errorf("task group %q doesn't contain task %q", tg.Name, r.task.Name)
	}

	// Merge in the task resources
	updatedTask.Resources = update.TaskResources[updatedTask.Name]

	// Update will update resources and store the new kill timeout.
	var mErr multierror.Error
	r.handleLock.Lock()
	if r.handle != nil {
		if err := r.handle.Update(updatedTask); err != nil {
			mErr.Errors = append(mErr.Errors, fmt.Errorf("updating task resources failed: %v", err))
		}
	}
	r.handleLock.Unlock()

	// Update the restart policy.
	if r.restartTracker != nil {
		r.restartTracker.SetPolicy(tg.RestartPolicy)
	}

	// Hash services returns the hash of the task's services
	hashServices := func(task *structs.Task) uint64 {
		h, err := hashstructure.Hash(task.Services, nil)
		if err != nil {
			mErr.Errors = append(mErr.Errors, fmt.Errorf("hashing services failed %#v: %v", task.Services, err))
		}
		return h
	}

	// Re-register the task to consul if any of the services have changed.
	if hashServices(updatedTask) != hashServices(r.task) {
		if err := r.consulService.Register(updatedTask, update); err != nil {
			mErr.Errors = append(mErr.Errors, fmt.Errorf("updating services with consul failed: %v", err))
		}
	}

	// Store the updated alloc.
	r.alloc = update
	r.task = updatedTask
	return mErr.ErrorOrNil()
}
Exemple #5
0
// NewTaskRunner is used to create a new task context
func NewTaskRunner(logger *log.Logger, config *config.Config,
	updater TaskStateUpdater, ctx *driver.ExecContext,
	alloc *structs.Allocation, task *structs.Task,
	consulService *ConsulService) *TaskRunner {

	// Merge in the task resources
	task.Resources = alloc.TaskResources[task.Name]

	// Build the restart tracker.
	tg := alloc.Job.LookupTaskGroup(alloc.TaskGroup)
	if tg == nil {
		logger.Printf("[ERR] client: alloc '%s' for missing task group '%s'", alloc.ID, alloc.TaskGroup)
		return nil
	}
	restartTracker := newRestartTracker(tg.RestartPolicy, alloc.Job.Type)

	tc := &TaskRunner{
		config:         config,
		updater:        updater,
		logger:         logger,
		restartTracker: restartTracker,
		consulService:  consulService,
		ctx:            ctx,
		alloc:          alloc,
		task:           task,
		updateCh:       make(chan *structs.Allocation, 8),
		destroyCh:      make(chan struct{}),
		waitCh:         make(chan struct{}),
	}
	return tc
}
Exemple #6
0
func parseServices(jobName string, taskGroupName string, task *structs.Task, serviceObjs *ast.ObjectList) error {
	task.Services = make([]*structs.Service, len(serviceObjs.Items))
	var defaultServiceName bool
	for idx, o := range serviceObjs.Items {
		// Check for invalid keys
		valid := []string{
			"name",
			"tags",
			"port",
			"check",
		}
		if err := checkHCLKeys(o.Val, valid); err != nil {
			return multierror.Prefix(err, fmt.Sprintf("service (%d) ->", idx))
		}

		var service structs.Service
		var m map[string]interface{}
		if err := hcl.DecodeObject(&m, o.Val); err != nil {
			return err
		}

		delete(m, "check")

		if err := mapstructure.WeakDecode(m, &service); err != nil {
			return err
		}

		if defaultServiceName && service.Name == "" {
			return fmt.Errorf("Only one service block may omit the Name field")
		}

		if service.Name == "" {
			defaultServiceName = true
			service.Name = fmt.Sprintf("%s-%s-%s", jobName, taskGroupName, task.Name)
		}

		// Filter checks
		var checkList *ast.ObjectList
		if ot, ok := o.Val.(*ast.ObjectType); ok {
			checkList = ot.List
		} else {
			return fmt.Errorf("service '%s': should be an object", service.Name)
		}

		if co := checkList.Filter("check"); len(co.Items) > 0 {
			if err := parseChecks(&service, co); err != nil {
				return multierror.Prefix(err, fmt.Sprintf("service: '%s',", service.Name))
			}
		}

		task.Services[idx] = &service
	}

	return nil
}
Exemple #7
0
// handleUpdate takes an updated allocation and updates internal state to
// reflect the new config for the task.
func (r *TaskRunner) handleUpdate(update *structs.Allocation) error {
	// Extract the task group from the alloc.
	tg := update.Job.LookupTaskGroup(update.TaskGroup)
	if tg == nil {
		return fmt.Errorf("alloc '%s' missing task group '%s'", update.ID, update.TaskGroup)
	}

	// Extract the task.
	var updatedTask *structs.Task
	for _, t := range tg.Tasks {
		if t.Name == r.task.Name {
			updatedTask = t
		}
	}
	if updatedTask == nil {
		return fmt.Errorf("task group %q doesn't contain task %q", tg.Name, r.task.Name)
	}

	// Merge in the task resources
	updatedTask.Resources = update.TaskResources[updatedTask.Name]

	// Update will update resources and store the new kill timeout.
	var mErr multierror.Error
	r.handleLock.Lock()
	if r.handle != nil {
		if err := r.handle.Update(updatedTask); err != nil {
			mErr.Errors = append(mErr.Errors, fmt.Errorf("updating task resources failed: %v", err))
		}
	}
	r.handleLock.Unlock()

	// Update the restart policy.
	if r.restartTracker != nil {
		r.restartTracker.SetPolicy(tg.RestartPolicy)
	}

	// Store the updated alloc.
	r.alloc = update
	r.task = updatedTask
	return mErr.ErrorOrNil()
}
Exemple #8
0
func TestTaskRunner_Update(t *testing.T) {
	ctestutil.ExecCompatible(t)
	_, tr := testTaskRunner()

	// Change command to ensure we run for a bit
	tr.task.Config["command"] = "/bin/sleep"
	tr.task.Config["args"] = "10"
	go tr.Run()
	defer tr.Destroy()
	defer tr.ctx.AllocDir.Destroy()

	// Update the task definition
	newTask := new(structs.Task)
	*newTask = *tr.task
	newTask.Driver = "foobar"
	tr.Update(newTask)

	// Wait for update to take place
	testutil.WaitForResult(func() (bool, error) {
		return tr.task == newTask, nil
	}, func(err error) {
		t.Fatalf("err: %v", err)
	})
}
Exemple #9
0
// NewTaskRunner is used to create a new task context
func NewTaskRunner(logger *log.Logger, config *config.Config,
	updater TaskStateUpdater, ctx *driver.ExecContext,
	alloc *structs.Allocation, task *structs.Task,
	vaultClient vaultclient.VaultClient) *TaskRunner {

	// Merge in the task resources
	task.Resources = alloc.TaskResources[task.Name]

	// Build the restart tracker.
	tg := alloc.Job.LookupTaskGroup(alloc.TaskGroup)
	if tg == nil {
		logger.Printf("[ERR] client: alloc '%s' for missing task group '%s'", alloc.ID, alloc.TaskGroup)
		return nil
	}
	restartTracker := newRestartTracker(tg.RestartPolicy, alloc.Job.Type)

	// Get the task directory
	taskDir, ok := ctx.AllocDir.TaskDirs[task.Name]
	if !ok {
		logger.Printf("[ERR] client: task directory for alloc %q task %q couldn't be found", alloc.ID, task.Name)
		return nil
	}

	tc := &TaskRunner{
		config:         config,
		updater:        updater,
		logger:         logger,
		restartTracker: restartTracker,
		ctx:            ctx,
		alloc:          alloc,
		task:           task,
		taskDir:        taskDir,
		vaultClient:    vaultClient,
		vaultFuture:    NewTokenFuture().Set(""),
		updateCh:       make(chan *structs.Allocation, 64),
		destroyCh:      make(chan struct{}),
		waitCh:         make(chan struct{}),
		startCh:        make(chan struct{}, 1),
		unblockCh:      make(chan struct{}),
		restartCh:      make(chan *structs.TaskEvent),
		signalCh:       make(chan SignalEvent),
	}

	return tc
}
Exemple #10
0
// NewTaskRunner is used to create a new task context
func NewTaskRunner(logger *log.Logger, config *config.Config,
	updater TaskStateUpdater, ctx *driver.ExecContext,
	alloc *structs.Allocation, task *structs.Task) *TaskRunner {

	// Merge in the task resources
	task.Resources = alloc.TaskResources[task.Name]

	// Build the restart tracker.
	tg := alloc.Job.LookupTaskGroup(alloc.TaskGroup)
	if tg == nil {
		logger.Printf("[ERR] client: alloc '%s' for missing task group '%s'", alloc.ID, alloc.TaskGroup)
		return nil
	}
	restartTracker := newRestartTracker(tg.RestartPolicy, alloc.Job.Type)

	resourceUsage, err := stats.NewRingBuff(config.StatsDataPoints)
	if err != nil {
		logger.Printf("[ERR] client: can't create resource usage buffer: %v", err)
		return nil
	}

	tc := &TaskRunner{
		config:         config,
		updater:        updater,
		logger:         logger,
		restartTracker: restartTracker,
		resourceUsage:  resourceUsage,
		ctx:            ctx,
		alloc:          alloc,
		task:           task,
		updateCh:       make(chan *structs.Allocation, 64),
		destroyCh:      make(chan struct{}),
		waitCh:         make(chan struct{}),
	}

	return tc
}
Exemple #11
0
func parseTasks(jobName string, taskGroupName string, result *[]*structs.Task, list *ast.ObjectList) error {
	list = list.Children()
	if len(list.Items) == 0 {
		return nil
	}

	// Go through each object and turn it into an actual result.
	seen := make(map[string]struct{})
	for _, item := range list.Items {
		n := item.Keys[0].Token.Value().(string)

		// Make sure we haven't already found this
		if _, ok := seen[n]; ok {
			return fmt.Errorf("task '%s' defined more than once", n)
		}
		seen[n] = struct{}{}

		// We need this later
		var listVal *ast.ObjectList
		if ot, ok := item.Val.(*ast.ObjectType); ok {
			listVal = ot.List
		} else {
			return fmt.Errorf("group '%s': should be an object", n)
		}

		// Check for invalid keys
		valid := []string{
			"artifact",
			"config",
			"constraint",
			"driver",
			"env",
			"kill_timeout",
			"logs",
			"meta",
			"resources",
			"service",
			"user",
			"vault",
		}
		if err := checkHCLKeys(listVal, valid); err != nil {
			return multierror.Prefix(err, fmt.Sprintf("'%s' ->", n))
		}

		var m map[string]interface{}
		if err := hcl.DecodeObject(&m, item.Val); err != nil {
			return err
		}
		delete(m, "artifact")
		delete(m, "config")
		delete(m, "constraint")
		delete(m, "env")
		delete(m, "logs")
		delete(m, "meta")
		delete(m, "resources")
		delete(m, "service")
		delete(m, "vault")

		// Build the task
		var t structs.Task
		t.Name = n
		if taskGroupName == "" {
			taskGroupName = n
		}
		dec, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
			DecodeHook:       mapstructure.StringToTimeDurationHookFunc(),
			WeaklyTypedInput: true,
			Result:           &t,
		})
		if err != nil {
			return err
		}
		if err := dec.Decode(m); err != nil {
			return err
		}

		// If we have env, then parse them
		if o := listVal.Filter("env"); len(o.Items) > 0 {
			for _, o := range o.Elem().Items {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o.Val); err != nil {
					return err
				}
				if err := mapstructure.WeakDecode(m, &t.Env); err != nil {
					return err
				}
			}
		}

		if o := listVal.Filter("service"); len(o.Items) > 0 {
			if err := parseServices(jobName, taskGroupName, &t, o); err != nil {
				return multierror.Prefix(err, fmt.Sprintf("'%s',", n))
			}
		}

		// If we have config, then parse that
		if o := listVal.Filter("config"); len(o.Items) > 0 {
			for _, o := range o.Elem().Items {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o.Val); err != nil {
					return err
				}

				if err := mapstructure.WeakDecode(m, &t.Config); err != nil {
					return err
				}
			}

			// Instantiate a driver to validate the configuration
			d, err := driver.NewDriver(
				t.Driver,
				driver.NewEmptyDriverContext(),
			)

			if err != nil {
				return multierror.Prefix(err,
					fmt.Sprintf("'%s', config ->", n))
			}

			if err := d.Validate(t.Config); err != nil {
				return multierror.Prefix(err,
					fmt.Sprintf("'%s', config ->", n))
			}
		}

		// Parse constraints
		if o := listVal.Filter("constraint"); len(o.Items) > 0 {
			if err := parseConstraints(&t.Constraints, o); err != nil {
				return multierror.Prefix(err, fmt.Sprintf(
					"'%s', constraint ->", n))
			}
		}

		// Parse out meta fields. These are in HCL as a list so we need
		// to iterate over them and merge them.
		if metaO := listVal.Filter("meta"); len(metaO.Items) > 0 {
			for _, o := range metaO.Elem().Items {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o.Val); err != nil {
					return err
				}
				if err := mapstructure.WeakDecode(m, &t.Meta); err != nil {
					return err
				}
			}
		}

		// If we have resources, then parse that
		if o := listVal.Filter("resources"); len(o.Items) > 0 {
			var r structs.Resources
			if err := parseResources(&r, o); err != nil {
				return multierror.Prefix(err, fmt.Sprintf("'%s',", n))
			}

			t.Resources = &r
		}

		// If we have logs then parse that
		logConfig := structs.DefaultLogConfig()
		if o := listVal.Filter("logs"); len(o.Items) > 0 {
			if len(o.Items) > 1 {
				return fmt.Errorf("only one logs block is allowed in a Task. Number of logs block found: %d", len(o.Items))
			}
			var m map[string]interface{}
			logsBlock := o.Items[0]

			// Check for invalid keys
			valid := []string{
				"max_files",
				"max_file_size",
			}
			if err := checkHCLKeys(logsBlock.Val, valid); err != nil {
				return multierror.Prefix(err, fmt.Sprintf("'%s', logs ->", n))
			}

			if err := hcl.DecodeObject(&m, logsBlock.Val); err != nil {
				return err
			}

			if err := mapstructure.WeakDecode(m, &logConfig); err != nil {
				return err
			}
		}
		t.LogConfig = logConfig

		// Parse artifacts
		if o := listVal.Filter("artifact"); len(o.Items) > 0 {
			if err := parseArtifacts(&t.Artifacts, o); err != nil {
				return multierror.Prefix(err, fmt.Sprintf("'%s', artifact ->", n))
			}
		}

		// If we have a vault block, then parse that
		if o := listVal.Filter("vault"); len(o.Items) > 0 {
			var v structs.Vault
			if err := parseVault(&v, o); err != nil {
				return multierror.Prefix(err, fmt.Sprintf("'%s', vault ->", n))
			}

			t.Vault = &v
		}

		*result = append(*result, &t)
	}

	return nil
}
Exemple #12
0
func parseTasks(result *[]*structs.Task, obj *hclobj.Object) error {
	// Get all the maps of keys to the actual object
	objects := make([]*hclobj.Object, 0, 5)
	set := make(map[string]struct{})
	for _, o1 := range obj.Elem(false) {
		for _, o2 := range o1.Elem(true) {
			if _, ok := set[o2.Key]; ok {
				return fmt.Errorf(
					"group '%s' defined more than once",
					o2.Key)
			}

			objects = append(objects, o2)
			set[o2.Key] = struct{}{}
		}
	}

	if len(objects) == 0 {
		return nil
	}

	for _, o := range objects {
		var m map[string]interface{}
		if err := hcl.DecodeObject(&m, o); err != nil {
			return err
		}
		delete(m, "config")
		delete(m, "constraint")
		delete(m, "meta")
		delete(m, "resources")

		// Build the task
		var t structs.Task
		t.Name = o.Key
		if err := mapstructure.WeakDecode(m, &t); err != nil {
			return err
		}

		// If we have config, then parse that
		if o := o.Get("config", false); o != nil {
			for _, o := range o.Elem(false) {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o); err != nil {
					return err
				}
				if err := mapstructure.WeakDecode(m, &t.Config); err != nil {
					return err
				}
			}
		}

		// Parse constraints
		if o := o.Get("constraint", false); o != nil {
			if err := parseConstraints(&t.Constraints, o); err != nil {
				return err
			}
		}

		// Parse out meta fields. These are in HCL as a list so we need
		// to iterate over them and merge them.
		if metaO := o.Get("meta", false); metaO != nil {
			for _, o := range metaO.Elem(false) {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o); err != nil {
					return err
				}
				if err := mapstructure.WeakDecode(m, &t.Meta); err != nil {
					return err
				}
			}
		}

		// If we have resources, then parse that
		if o := o.Get("resources", false); o != nil {
			var r structs.Resources
			if err := parseResources(&r, o); err != nil {
				return fmt.Errorf("task '%s': %s", t.Name, err)
			}

			t.Resources = &r
		}

		*result = append(*result, &t)
	}

	return nil
}
Exemple #13
0
func parseTasks(jobName string, taskGroupName string, result *[]*structs.Task, list *ast.ObjectList) error {
	list = list.Children()
	if len(list.Items) == 0 {
		return nil
	}

	// Go through each object and turn it into an actual result.
	seen := make(map[string]struct{})
	for _, item := range list.Items {
		n := item.Keys[0].Token.Value().(string)

		// Make sure we haven't already found this
		if _, ok := seen[n]; ok {
			return fmt.Errorf("task '%s' defined more than once", n)
		}
		seen[n] = struct{}{}

		// We need this later
		var listVal *ast.ObjectList
		if ot, ok := item.Val.(*ast.ObjectType); ok {
			listVal = ot.List
		} else {
			return fmt.Errorf("group '%s': should be an object", n)
		}

		var m map[string]interface{}
		if err := hcl.DecodeObject(&m, item.Val); err != nil {
			return err
		}
		delete(m, "config")
		delete(m, "env")
		delete(m, "constraint")
		delete(m, "service")
		delete(m, "meta")
		delete(m, "resources")

		// Build the task
		var t structs.Task
		t.Name = n
		if taskGroupName == "" {
			taskGroupName = n
		}
		dec, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
			DecodeHook:       mapstructure.StringToTimeDurationHookFunc(),
			WeaklyTypedInput: true,
			Result:           &t,
		})
		if err != nil {
			return err
		}
		if err := dec.Decode(m); err != nil {
			return err
		}

		// If we have env, then parse them
		if o := listVal.Filter("env"); len(o.Items) > 0 {
			for _, o := range o.Elem().Items {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o.Val); err != nil {
					return err
				}
				if err := mapstructure.WeakDecode(m, &t.Env); err != nil {
					return err
				}
			}
		}

		if o := listVal.Filter("service"); len(o.Items) > 0 {
			if err := parseServices(jobName, taskGroupName, &t, o); err != nil {
				return err
			}
		}

		// If we have config, then parse that
		if o := listVal.Filter("config"); len(o.Items) > 0 {
			for _, o := range o.Elem().Items {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o.Val); err != nil {
					return err
				}

				if err := mapstructure.WeakDecode(m, &t.Config); err != nil {
					return err
				}
			}
		}

		// Parse constraints
		if o := listVal.Filter("constraint"); len(o.Items) > 0 {
			if err := parseConstraints(&t.Constraints, o); err != nil {
				return err
			}
		}

		// Parse out meta fields. These are in HCL as a list so we need
		// to iterate over them and merge them.
		if metaO := listVal.Filter("meta"); len(metaO.Items) > 0 {
			for _, o := range metaO.Elem().Items {
				var m map[string]interface{}
				if err := hcl.DecodeObject(&m, o.Val); err != nil {
					return err
				}
				if err := mapstructure.WeakDecode(m, &t.Meta); err != nil {
					return err
				}
			}
		}

		// If we have resources, then parse that
		if o := listVal.Filter("resources"); len(o.Items) > 0 {
			var r structs.Resources
			if err := parseResources(&r, o); err != nil {
				return fmt.Errorf("task '%s': %s", t.Name, err)
			}

			t.Resources = &r
		}

		*result = append(*result, &t)
	}

	return nil
}
Exemple #14
0
// SetTaskEnv configures the environment of t so that Run executes a testtask
// script when called from within t.
func SetTaskEnv(t *structs.Task) {
	if t.Env == nil {
		t.Env = map[string]string{}
	}
	t.Env["TEST_TASK"] = "execute"
}