@@ -275,6 +275,12 @@ type ServiceCreateResponse struct {

 	ID string

 }

+// Values for RegistryAuthFrom in ServiceUpdateOptions

+const (

+	RegistryAuthFromSpec         = "spec"

+	RegistryAuthFromPreviousSpec = "previous-spec"

+)

+

 // ServiceUpdateOptions contains the options to be used for updating services.

 type ServiceUpdateOptions struct {

 	// EncodedRegistryAuth is the encoded registry authorization credentials to

@@ -286,6 +292,11 @@ type ServiceUpdateOptions struct {

 	// TODO(stevvooe): Consider moving the version parameter of ServiceUpdate

 	// into this field. While it does open API users up to racy writes, most

 	// users may not need that level of consistency in practice.

+

+	// RegistryAuthFrom specifies where to find the registry authorization

+	// credentials if they are not given in EncodedRegistryAuth. Valid

+	// values are "spec" and "previous-spec".

+	RegistryAuthFrom string

 }

 // ServiceListOptions holds parameters to list  services with.

@@ -7,6 +7,7 @@ type Service struct {

 	ID string

 	Meta

 	Spec         ServiceSpec  `json:",omitempty"`

+	PreviousSpec *ServiceSpec `json:",omitempty"`

 	Endpoint     Endpoint     `json:",omitempty"`

 	UpdateStatus UpdateStatus `json:",omitempty"`

 }

@@ -71,7 +72,34 @@ const (

 // UpdateConfig represents the update configuration.

 type UpdateConfig struct {

-	Parallelism   uint64        `json:",omitempty"`

-	Delay         time.Duration `json:",omitempty"`

-	FailureAction string        `json:",omitempty"`

+	// Maximum number of tasks to be updated in one iteration.

+	// 0 means unlimited parallelism.

+	Parallelism uint64 `json:",omitempty"`

+

+	// Amount of time between updates.

+	Delay time.Duration `json:",omitempty"`

+

+	// FailureAction is the action to take when an update failures.

+	FailureAction string `json:",omitempty"`

+

+	// Monitor indicates how long to monitor a task for failure after it is

+	// created. If the task fails by ending up in one of the states

+	// REJECTED, COMPLETED, or FAILED, within Monitor from its creation,

+	// this counts as a failure. If it fails after Monitor, it does not

+	// count as a failure. If Monitor is unspecified, a default value will

+	// be used.

+	Monitor time.Duration `json:",omitempty"`

+

+	// AllowedFailureFraction is the fraction of tasks that may fail during

+	// an update before the failure action is invoked. Any task created by

+	// the current update which ends up in one of the states REJECTED,

+	// COMPLETED or FAILED within Monitor from its creation counts as a

+	// failure. The number of failures is divided by the number of tasks

+	// being updated, and if this fraction is greater than

+	// AllowedFailureFraction, the failure action is invoked.

+	//

+	// If the failure action is CONTINUE, there is no effect.

+	// If the failure action is PAUSE, no more tasks will be updated until

+	// another update is started.

+	AllowedFailureFraction float32

 }

@@ -22,6 +22,10 @@ func (cli *Client) ServiceUpdate(ctx context.Context, serviceID string, version

 		}

 	}

+	if options.RegistryAuthFrom != "" {

+		query.Set("registryAuthFrom", options.RegistryAuthFrom)

+	}

+

 	query.Set("version", strconv.FormatUint(version.Index, 10))

 	resp, err := cli.post(ctx, "/services/"+serviceID+"/update", query, service, headers)