REST Resource: projects.configs.waiters

Resource: Waiter

A Waiter resource waits for some end condition within a RuntimeConfig resource to be met before it returns. For example, assume you have a distributed system where each node writes to a Variable resource indicating the node's readiness as part of the startup process.

You then configure a Waiter resource with the success condition set to wait until some number of nodes have checked in. Afterwards, your application runs some arbitrary code after the condition has been met and the waiter returns successfully.

Once created, a Waiter resource is immutable.

To learn more about using waiters, read the Creating a Waiter documentation.

JSON representation 
{
  "name": string,
  "timeout": string,
  "failure": {
    object(EndCondition)
  },
  "success": {
    object(EndCondition)
  },
  "createTime": string,
  "done": boolean,
  "error": {
    object(Status)
  }
}
Fields
name

string

The name of the Waiter resource, in the format:

projects/[PROJECT_ID]/configs/[CONFIG_NAME]/waiters/[WAITER_NAME]

The [PROJECT_ID] must be a valid Google Cloud project ID, the [CONFIG_NAME] must be a valid RuntimeConfig resource, the [WAITER_NAME] must match RFC 1035 segment specification, and the length of [WAITER_NAME] must be less than 64 bytes.

After you create a Waiter resource, you cannot change the resource name.
timeout

string (Duration format)

[Required] Specifies the timeout of the waiter in seconds, beginning from the instant that waiters().create method is called. If this time elapses before the success or failure conditions are met, the waiter fails and sets the error code to DEADLINE_EXCEEDED.

A duration in seconds with up to nine fractional digits, terminated by 's'. Example: "3.5s".
failure

object(EndCondition)

[Optional] The failure condition of this waiter. If this condition is met, done will be set to true and the error code will be set to ABORTED. The failure condition takes precedence over the success condition. If both conditions are met, a failure will be indicated. This value is optional; if no failure condition is set, the only failure scenario will be a timeout.

success

object(EndCondition)

[Required] The success condition. If this condition is met, done will be set to true and the error value will remain unset. The failure condition takes precedence over the success condition. If both conditions are met, a failure will be indicated.

createTime

string (Timestamp format)

Output only. The instant at which this Waiter resource was created. Adding the value of timeout to this instant yields the timeout deadline for the waiter.

A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".
done

boolean

Output only. If the value is false, it means the waiter is still waiting for one of its conditions to be met.

If true, the waiter has finished. If the waiter finished due to a timeout or failure, error will be set.
error

object(Status)

Output only. If the waiter ended due to a failure or timeout, this value will be set.

EndCondition

The condition that a Waiter resource is waiting for.

JSON representation 
{
  "cardinality": {
    object(Cardinality)
  }
}
Fields
cardinality

object(Cardinality)

The cardinality of the EndCondition.

Cardinality

A Cardinality condition for the Waiter resource. A cardinality condition is met when the number of variables under a specified path prefix reaches a predefined number. For example, if you set a Cardinality condition where the path is set to /foo and the number of paths is set to 2, the following variables would meet the condition in a RuntimeConfig resource:

  • /foo/variable1 = "value1"
  • /foo/variable2 = "value2"
  • /bar/variable3 = "value3"

It would not satisfy the same condition with the number set to 3, however, because there is only 2 paths that start with /foo. Cardinality conditions are recursive; all subtrees under the specific path prefix are counted.

JSON representation 
{
  "path": string,
  "number": number
}
Fields
path

string

The root of the variable subtree to monitor. For example, /foo.

number

number

The number variables under the path that must exist to meet this condition. Defaults to 1 if not specified.

Methods

create

 Creates a Waiter resource.

delete

 Deletes the waiter with the specified name.

get

 Gets information about a single waiter.

list

 List waiters within the given configuration.

testIamPermissions

 Returns permissions that a caller has on the specified resource.