tasks/v2beta2/target.proto

// Copyright 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto3";

package google.cloud.tasks.v2beta2;

import "google/api/field_behavior.proto";

option go_package = "cloud.google.com/go/cloudtasks/apiv2beta2/cloudtaskspb;cloudtaskspb";
option java_multiple_files = true;
option java_outer_classname = "TargetProto";
option java_package = "com.google.cloud.tasks.v2beta2";

// Pull target.
message PullTarget {}

// The pull message contains data that can be used by the caller of
// [LeaseTasks][google.cloud.tasks.v2beta2.CloudTasks.LeaseTasks] to process the
// task.
//
// This proto can only be used for tasks in a queue which has
// [pull_target][google.cloud.tasks.v2beta2.Queue.pull_target] set.
message PullMessage {
  // A data payload consumed by the worker to execute the task.
  bytes payload = 1;

  // The task's tag.
  //
  // Tags allow similar tasks to be processed in a batch. If you label
  // tasks with a tag, your worker can
  // [lease tasks][google.cloud.tasks.v2beta2.CloudTasks.LeaseTasks] with the
  // same tag using
  // [filter][google.cloud.tasks.v2beta2.LeaseTasksRequest.filter]. For example,
  // if you want to aggregate the events associated with a specific user once a
  // day, you could tag tasks with the user ID.
  //
  // The task's tag can only be set when the
  // [task is created][google.cloud.tasks.v2beta2.CloudTasks.CreateTask].
  //
  // The tag must be less than 500 characters.
  //
  // SDK compatibility: Although the SDK allows tags to be either
  // string or
  // [bytes](https://cloud.google.com/appengine/docs/standard/java/javadoc/com/google/appengine/api/taskqueue/TaskOptions.html#tag-byte:A-),
  // only UTF-8 encoded tags can be used in Cloud Tasks. If a tag isn't UTF-8
  // encoded, the tag will be empty when the task is returned by Cloud Tasks.
  string tag = 2;
}

// App Engine HTTP target.
//
// The task will be delivered to the App Engine application hostname
// specified by its
// [AppEngineHttpTarget][google.cloud.tasks.v2beta2.AppEngineHttpTarget] and
// [AppEngineHttpRequest][google.cloud.tasks.v2beta2.AppEngineHttpRequest]. The
// documentation for
// [AppEngineHttpRequest][google.cloud.tasks.v2beta2.AppEngineHttpRequest]
// explains how the task's host URL is constructed.
//
// Using [AppEngineHttpTarget][google.cloud.tasks.v2beta2.AppEngineHttpTarget]
// requires
// [`appengine.applications.get`](https://cloud.google.com/appengine/docs/admin-api/access-control)
// Google IAM permission for the project
// and the following scope:
//
// `https://www.googleapis.com/auth/cloud-platform`
message AppEngineHttpTarget {
  // Overrides for the
  // [task-level
  // app_engine_routing][google.cloud.tasks.v2beta2.AppEngineHttpRequest.app_engine_routing].
  //
  // If set, `app_engine_routing_override` is used for all tasks in
  // the queue, no matter what the setting is for the
  // [task-level
  // app_engine_routing][google.cloud.tasks.v2beta2.AppEngineHttpRequest.app_engine_routing].
  AppEngineRouting app_engine_routing_override = 1;
}

// App Engine HTTP request.
//
// The message defines the HTTP request that is sent to an App Engine app when
// the task is dispatched.
//
// This proto can only be used for tasks in a queue which has
// [app_engine_http_target][google.cloud.tasks.v2beta2.Queue.app_engine_http_target]
// set.
//
// Using [AppEngineHttpRequest][google.cloud.tasks.v2beta2.AppEngineHttpRequest]
// requires
// [`appengine.applications.get`](https://cloud.google.com/appengine/docs/admin-api/access-control)
// Google IAM permission for the project
// and the following scope:
//
// `https://www.googleapis.com/auth/cloud-platform`
//
// The task will be delivered to the App Engine app which belongs to the same
// project as the queue. For more information, see
// [How Requests are
// Routed](https://cloud.google.com/appengine/docs/standard/python/how-requests-are-routed)
// and how routing is affected by
// [dispatch
// files](https://cloud.google.com/appengine/docs/python/config/dispatchref).
// Traffic is encrypted during transport and never leaves Google datacenters.
// Because this traffic is carried over a communication mechanism internal to
// Google, you cannot explicitly set the protocol (for example, HTTP or HTTPS).
// The request to the handler, however, will appear to have used the HTTP
// protocol.
//
// The [AppEngineRouting][google.cloud.tasks.v2beta2.AppEngineRouting] used to
// construct the URL that the task is delivered to can be set at the queue-level
// or task-level:
//
// * If set,
//   [app_engine_routing_override][google.cloud.tasks.v2beta2.AppEngineHttpTarget.app_engine_routing_override]
//   is used for all tasks in the queue, no matter what the setting
//   is for the
//   [task-level
//   app_engine_routing][google.cloud.tasks.v2beta2.AppEngineHttpRequest.app_engine_routing].
//
//
// The `url` that the task will be sent to is:
//
// * `url =` [host][google.cloud.tasks.v2beta2.AppEngineRouting.host] `+`
//   [relative_url][google.cloud.tasks.v2beta2.AppEngineHttpRequest.relative_url]
//
// Tasks can be dispatched to secure app handlers, unsecure app handlers, and
// URIs restricted with
// [`login:
// admin`](https://cloud.google.com/appengine/docs/standard/python/config/appref).
// Because tasks are not run as any user, they cannot be dispatched to URIs
// restricted with
// [`login:
// required`](https://cloud.google.com/appengine/docs/standard/python/config/appref)
// Task dispatches also do not follow redirects.
//
// The task attempt has succeeded if the app's request handler returns an HTTP
// response code in the range [`200` - `299`]. The task attempt has failed if
// the app's handler returns a non-2xx response code or Cloud Tasks does
// not receive response before the [deadline][Task.dispatch_deadline]. Failed
// tasks will be retried according to the
// [retry configuration][google.cloud.tasks.v2beta2.Queue.retry_config]. `503`
// (Service Unavailable) is considered an App Engine system error instead of an
// application error and will cause Cloud Tasks' traffic congestion control to
// temporarily throttle the queue's dispatches. Unlike other types of task
// targets, a `429` (Too Many Requests) response from an app handler does not
// cause traffic congestion control to throttle the queue.
message AppEngineHttpRequest {
  // The HTTP method to use for the request. The default is POST.
  //
  // The app's request handler for the task's target URL must be able to handle
  // HTTP requests with this http_method, otherwise the task attempt fails with
  // error code 405 (Method Not Allowed). See [Writing a push task request
  // handler](https://cloud.google.com/appengine/docs/java/taskqueue/push/creating-handlers#writing_a_push_task_request_handler)
  // and the App Engine documentation for your runtime on [How Requests are
  // Handled](https://cloud.google.com/appengine/docs/standard/python3/how-requests-are-handled).
  HttpMethod http_method = 1;

  // Task-level setting for App Engine routing.
  //
  // If set,
  // [app_engine_routing_override][google.cloud.tasks.v2beta2.AppEngineHttpTarget.app_engine_routing_override]
  // is used for all tasks in the queue, no matter what the setting is for the
  // [task-level
  // app_engine_routing][google.cloud.tasks.v2beta2.AppEngineHttpRequest.app_engine_routing].
  AppEngineRouting app_engine_routing = 2;

  // The relative URL.
  //
  // The relative URL must begin with "/" and must be a valid HTTP relative URL.
  // It can contain a path and query string arguments.
  // If the relative URL is empty, then the root path "/" will be used.
  // No spaces are allowed, and the maximum length allowed is 2083 characters.
  string relative_url = 3;

  // HTTP request headers.
  //
  // This map contains the header field names and values.
  // Headers can be set when the
  // [task is created][google.cloud.tasks.v2beta2.CloudTasks.CreateTask].
  // Repeated headers are not supported but a header value can contain commas.
  //
  // Cloud Tasks sets some headers to default values:
  //
  // * `User-Agent`: By default, this header is
  //   `"AppEngine-Google; (+http://code.google.com/appengine)"`.
  //   This header can be modified, but Cloud Tasks will append
  //   `"AppEngine-Google; (+http://code.google.com/appengine)"` to the
  //   modified `User-Agent`.
  //
  // If the task has a
  // [payload][google.cloud.tasks.v2beta2.AppEngineHttpRequest.payload], Cloud
  // Tasks sets the following headers:
  //
  // * `Content-Type`: By default, the `Content-Type` header is set to
  //   `"application/octet-stream"`. The default can be overridden by explicitly
  //   setting `Content-Type` to a particular media type when the
  //   [task is created][google.cloud.tasks.v2beta2.CloudTasks.CreateTask].
  //   For example, `Content-Type` can be set to `"application/json"`.
  // * `Content-Length`: This is computed by Cloud Tasks. This value is
  //   output only.   It cannot be changed.
  //
  // The headers below cannot be set or overridden:
  //
  // * `Host`
  // * `X-Google-*`
  // * `X-AppEngine-*`
  //
  // In addition, Cloud Tasks sets some headers when the task is dispatched,
  // such as headers containing information about the task; see
  // [request
  // headers](https://cloud.google.com/appengine/docs/python/taskqueue/push/creating-handlers#reading_request_headers).
  // These headers are set only when the task is dispatched, so they are not
  // visible when the task is returned in a Cloud Tasks response.
  //
  // Although there is no specific limit for the maximum number of headers or
  // the size, there is a limit on the maximum size of the
  // [Task][google.cloud.tasks.v2beta2.Task]. For more information, see the
  // [CreateTask][google.cloud.tasks.v2beta2.CloudTasks.CreateTask]
  // documentation.
  map<string, string> headers = 4;

  // Payload.
  //
  // The payload will be sent as the HTTP message body. A message
  // body, and thus a payload, is allowed only if the HTTP method is
  // POST or PUT. It is an error to set a data payload on a task with
  // an incompatible [HttpMethod][google.cloud.tasks.v2beta2.HttpMethod].
  bytes payload = 5;
}

// App Engine Routing.
//
// Defines routing characteristics specific to App Engine - service, version,
// and instance.
//
// For more information about services, versions, and instances see
// [An Overview of App
// Engine](https://cloud.google.com/appengine/docs/python/an-overview-of-app-engine),
// [Microservices Architecture on Google App
// Engine](https://cloud.google.com/appengine/docs/python/microservices-on-app-engine),
// [App Engine Standard request
// routing](https://cloud.google.com/appengine/docs/standard/python/how-requests-are-routed),
// and [App Engine Flex request
// routing](https://cloud.google.com/appengine/docs/flexible/python/how-requests-are-routed).
message AppEngineRouting {
  // App service.
  //
  // By default, the task is sent to the service which is the default
  // service when the task is attempted.
  //
  // For some queues or tasks which were created using the App Engine
  // Task Queue API, [host][google.cloud.tasks.v2beta2.AppEngineRouting.host] is
  // not parsable into
  // [service][google.cloud.tasks.v2beta2.AppEngineRouting.service],
  // [version][google.cloud.tasks.v2beta2.AppEngineRouting.version], and
  // [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance]. For
  // example, some tasks which were created using the App Engine SDK use a
  // custom domain name; custom domains are not parsed by Cloud Tasks. If
  // [host][google.cloud.tasks.v2beta2.AppEngineRouting.host] is not parsable,
  // then [service][google.cloud.tasks.v2beta2.AppEngineRouting.service],
  // [version][google.cloud.tasks.v2beta2.AppEngineRouting.version], and
  // [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance] are the
  // empty string.
  string service = 1;

  // App version.
  //
  // By default, the task is sent to the version which is the default
  // version when the task is attempted.
  //
  // For some queues or tasks which were created using the App Engine
  // Task Queue API, [host][google.cloud.tasks.v2beta2.AppEngineRouting.host] is
  // not parsable into
  // [service][google.cloud.tasks.v2beta2.AppEngineRouting.service],
  // [version][google.cloud.tasks.v2beta2.AppEngineRouting.version], and
  // [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance]. For
  // example, some tasks which were created using the App Engine SDK use a
  // custom domain name; custom domains are not parsed by Cloud Tasks. If
  // [host][google.cloud.tasks.v2beta2.AppEngineRouting.host] is not parsable,
  // then [service][google.cloud.tasks.v2beta2.AppEngineRouting.service],
  // [version][google.cloud.tasks.v2beta2.AppEngineRouting.version], and
  // [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance] are the
  // empty string.
  string version = 2;

  // App instance.
  //
  // By default, the task is sent to an instance which is available when
  // the task is attempted.
  //
  // Requests can only be sent to a specific instance if
  // [manual scaling is used in App Engine
  // Standard](https://cloud.google.com/appengine/docs/python/an-overview-of-app-engine?hl=en_US#scaling_types_and_instance_classes).
  // App Engine Flex does not support instances. For more information, see
  // [App Engine Standard request
  // routing](https://cloud.google.com/appengine/docs/standard/python/how-requests-are-routed)
  // and [App Engine Flex request
  // routing](https://cloud.google.com/appengine/docs/flexible/python/how-requests-are-routed).
  string instance = 3;

  // Output only. The host that the task is sent to.
  //
  // For more information, see
  // [How Requests are
  // Routed](https://cloud.google.com/appengine/docs/standard/python/how-requests-are-routed).
  //
  // The host is constructed as:
  //
  //
  // * `host = [application_domain_name]`</br>
  //   `| [service] + '.' + [application_domain_name]`</br>
  //   `| [version] + '.' + [application_domain_name]`</br>
  //   `| [version_dot_service]+ '.' + [application_domain_name]`</br>
  //   `| [instance] + '.' + [application_domain_name]`</br>
  //   `| [instance_dot_service] + '.' + [application_domain_name]`</br>
  //   `| [instance_dot_version] + '.' + [application_domain_name]`</br>
  //   `| [instance_dot_version_dot_service] + '.' + [application_domain_name]`
  //
  // * `application_domain_name` = The domain name of the app, for
  //   example <app-id>.appspot.com, which is associated with the
  //   queue's project ID. Some tasks which were created using the App Engine
  //   SDK use a custom domain name.
  //
  // * `service =`
  // [service][google.cloud.tasks.v2beta2.AppEngineRouting.service]
  //
  // * `version =`
  // [version][google.cloud.tasks.v2beta2.AppEngineRouting.version]
  //
  // * `version_dot_service =`
  //   [version][google.cloud.tasks.v2beta2.AppEngineRouting.version] `+ '.' +`
  //   [service][google.cloud.tasks.v2beta2.AppEngineRouting.service]
  //
  // * `instance =`
  // [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance]
  //
  // * `instance_dot_service =`
  //   [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance] `+ '.'
  //   +` [service][google.cloud.tasks.v2beta2.AppEngineRouting.service]
  //
  // * `instance_dot_version =`
  //   [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance] `+ '.'
  //   +` [version][google.cloud.tasks.v2beta2.AppEngineRouting.version]
  //
  // * `instance_dot_version_dot_service =`
  //   [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance] `+ '.'
  //   +` [version][google.cloud.tasks.v2beta2.AppEngineRouting.version] `+ '.'
  //   +` [service][google.cloud.tasks.v2beta2.AppEngineRouting.service]
  //
  // If [service][google.cloud.tasks.v2beta2.AppEngineRouting.service] is empty,
  // then the task will be sent to the service which is the default service when
  // the task is attempted.
  //
  // If [version][google.cloud.tasks.v2beta2.AppEngineRouting.version] is empty,
  // then the task will be sent to the version which is the default version when
  // the task is attempted.
  //
  // If [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance] is
  // empty, then the task will be sent to an instance which is available when
  // the task is attempted.
  //
  // If [service][google.cloud.tasks.v2beta2.AppEngineRouting.service],
  // [version][google.cloud.tasks.v2beta2.AppEngineRouting.version], or
  // [instance][google.cloud.tasks.v2beta2.AppEngineRouting.instance] is
  // invalid, then the task will be sent to the default version of the default
  // service when the task is attempted.
  string host = 4;
}

// HTTP request.
//
// The task will be pushed to the worker as an HTTP request. An HTTP request
// embodies a url, an http method, headers, body and authorization for the http
// task.
message HttpRequest {
  // Required. The full url path that the request will be sent to.
  //
  // This string must begin with either "http://" or "https://". Some examples
  // are: `http://acme.com` and `https://acme.com/sales:8080`. Cloud Tasks will
  // encode some characters for safety and compatibility. The maximum allowed
  // URL length is 2083 characters after encoding.
  //
  // The `Location` header response from a redirect response [`300` - `399`]
  // may be followed. The redirect is not counted as a separate attempt.
  string url = 1 [(google.api.field_behavior) = REQUIRED];

  // The HTTP method to use for the request. The default is POST.
  HttpMethod http_method = 2;

  // HTTP request headers.
  //
  // This map contains the header field names and values.
  // Headers can be set when running the
  // [task is created][google.cloud.tasks.v2beta2.CloudTasks.CreateTask] or
  // [task is created][google.cloud.tasks.v2beta2.CloudTasks.BufferTask].
  //
  // These headers represent a subset of the headers that will accompany the
  // task's HTTP request. Some HTTP request headers will be ignored or replaced.
  //
  // A partial list of headers that will be ignored or replaced is:
  //
  // * Any header that is prefixed with "X-CloudTasks-" will be treated
  // as service header. Service headers define properties of the task and are
  // predefined in CloudTask.
  // * Host: This will be computed by Cloud Tasks and derived from
  //   [HttpRequest.url][google.cloud.tasks.v2beta2.HttpRequest.url].
  // * Content-Length: This will be computed by Cloud Tasks.
  // * User-Agent: This will be set to `"Google-Cloud-Tasks"`.
  // * `X-Google-*`: Google use only.
  // * `X-AppEngine-*`: Google use only.
  //
  // `Content-Type` won't be set by Cloud Tasks. You can explicitly set
  // `Content-Type` to a media type when the
  //  [task is created][google.cloud.tasks.v2beta3.CloudTasks.CreateTask].
  //  For example, `Content-Type` can be set to `"application/octet-stream"` or
  //  `"application/json"`.
  //
  // Headers which can have multiple values (according to RFC2616) can be
  // specified using comma-separated values.
  //
  // The size of the headers must be less than 80KB.
  map<string, string> headers = 3;

  // HTTP request body.
  //
  // A request body is allowed only if the
  // [HTTP method][google.cloud.tasks.v2beta2.HttpRequest.http_method] is POST,
  // PUT, or PATCH. It is an error to set body on a task with an incompatible
  // [HttpMethod][google.cloud.tasks.v2beta2.HttpMethod].
  bytes body = 4;

  // The mode for generating an `Authorization` header for HTTP requests.
  //
  // If specified, all `Authorization` headers in the
  // [HttpRequest.headers][google.cloud.tasks.v2beta2.HttpRequest.headers] field
  // will be overridden.
  oneof authorization_header {
    // If specified, an
    // [OAuth token](https://developers.google.com/identity/protocols/OAuth2)
    // will be generated and attached as an `Authorization` header in the HTTP
    // request.
    //
    // This type of authorization should generally only be used when calling
    // Google APIs hosted on *.googleapis.com.
    OAuthToken oauth_token = 5;

    // If specified, an
    // [OIDC](https://developers.google.com/identity/protocols/OpenIDConnect)
    // token will be generated and attached as an `Authorization` header in the
    // HTTP request.
    //
    // This type of authorization can be used for many scenarios, including
    // calling Cloud Run, or endpoints where you intend to validate the token
    // yourself.
    OidcToken oidc_token = 6;
  }
}

// PathOverride.
//
// Path message defines path override for HTTP targets.
message PathOverride {
  // The URI path (e.g., /users/1234). Default is an empty string.
  string path = 1;
}

// QueryOverride.
//
// Query message defines query override for HTTP targets.
message QueryOverride {
  // The query parameters (e.g., qparam1=123&qparam2=456). Default is an empty
  // string.
  string query_params = 1;
}

// Uri Override.
//
// When specified, all the HTTP tasks inside the queue will be partially or
// fully overridden depending on the configured values.
message UriOverride {
  // The Scheme for an HTTP request. By default, it is HTTPS.
  enum Scheme {
    // Scheme unspecified. Defaults to HTTPS.
    SCHEME_UNSPECIFIED = 0;

    // Convert the scheme to HTTP, e.g., https://www.google.ca will change to
    // http://www.google.ca.
    HTTP = 1;

    // Convert the scheme to HTTPS, e.g., http://www.google.ca will change to
    // https://www.google.ca.
    HTTPS = 2;
  }

  // UriOverrideEnforceMode mode is to define enforcing mode for the override
  // modes.
  enum UriOverrideEnforceMode {
    // OverrideMode Unspecified. Defaults to ALWAYS.
    URI_OVERRIDE_ENFORCE_MODE_UNSPECIFIED = 0;

    // In the IF_NOT_EXISTS mode, queue-level configuration is only
    // applied where task-level configuration does not exist.
    IF_NOT_EXISTS = 1;

    // In the ALWAYS mode, queue-level configuration overrides all
    // task-level configuration
    ALWAYS = 2;
  }

  // Scheme override.
  //
  // When specified, the task URI scheme is replaced by the provided value (HTTP
  // or HTTPS).
  optional Scheme scheme = 1;

  // Host override.
  //
  // When specified, replaces the host part of the task URL. For example,
  // if the task URL is "https://www.google.com," and host value is set to
  // "example.net", the overridden URI will be changed to "https://example.net."
  // Host value cannot be an empty string (INVALID_ARGUMENT).
  optional string host = 2;

  // Port override.
  //
  // When specified, replaces the port part of the task URI. For instance,
  // for a URI http://www.google.com/foo and port=123, the overridden URI
  // becomes http://www.google.com:123/foo. Note that the port value must be a
  // positive integer. Setting the port to 0 (Zero) clears the URI port.
  optional int64 port = 3;

  // URI path.
  //
  // When specified, replaces the existing path of the task URL. Setting the
  // path value to an empty string clears the URI path segment.
  PathOverride path_override = 4;

  // URI Query.
  //
  // When specified, replaces the query part of the task URI. Setting the
  // query value to an empty string clears the URI query segment.
  QueryOverride query_override = 5;

  // URI Override Enforce Mode
  //
  // When specified, determines the Target UriOverride mode. If not specified,
  // it defaults to ALWAYS.
  UriOverrideEnforceMode uri_override_enforce_mode = 6;
}

// HTTP target.
//
// When specified as a [Queue][target_type], all the tasks with [HttpRequest]
// will be overridden according to the target.
message HttpTarget {
  // Defines a header message. A header can have a key and a value.
  message Header {
    // The key of the header.
    string key = 1;

    // The value of the header.
    string value = 2;
  }

  // Wraps the Header object.
  message HeaderOverride {
    // header embodying a key and a value.
    Header header = 1;
  }

  // Uri override.
  //
  // When specified, overrides the execution Uri for all the tasks in the queue.
  UriOverride uri_override = 1;

  // The HTTP method to use for the request.
  //
  // When specified, it overrides
  // [HttpRequest][google.cloud.tasks.v2beta2.HttpTarget.http_method] for the
  // task. Note that if the value is set to [HttpMethod][GET] the
  // [HttpRequest][body] of the task will be ignored at execution time.
  HttpMethod http_method = 2;

  // HTTP target headers.
  //
  // This map contains the header field names and values.
  // Headers will be set when running the
  // [task is created][google.cloud.tasks.v2beta2.CloudTasks.CreateTask] and/or
  // [task is created][google.cloud.tasks.v2beta2.CloudTasks.BufferTask].
  //
  // These headers represent a subset of the headers that will accompany the
  // task's HTTP request. Some HTTP request headers will be ignored or replaced.
  //
  // A partial list of headers that will be ignored or replaced is:
  // * Any header that is prefixed with "X-CloudTasks-" will be treated
  // as service header. Service headers define properties of the task and are
  // predefined in CloudTask.
  // * Host: This will be computed by Cloud Tasks and derived from
  //   [HttpRequest.url][google.cloud.tasks.v2beta2.HttpRequest.url].
  // * Content-Length: This will be computed by Cloud Tasks.
  // * User-Agent: This will be set to `"Google-CloudTasks"`.
  // * `X-Google-*`: Google use only.
  // * `X-AppEngine-*`: Google use only.
  //
  // `Content-Type` won't be set by Cloud Tasks. You can explicitly set
  // `Content-Type` to a media type when the
  //  [task is created][google.cloud.tasks.v2beta3.CloudTasks.CreateTask].
  //  For example, `Content-Type` can be set to `"application/octet-stream"` or
  //  `"application/json"`.
  //
  // Headers which can have multiple values (according to RFC2616) can be
  // specified using comma-separated values.
  //
  // The size of the headers must be less than 80KB.
  // Queue-level headers to override headers of all the tasks in the queue.
  repeated HeaderOverride header_overrides = 3;

  // The mode for generating an `Authorization` header for HTTP requests.
  //
  // If specified, all `Authorization` headers in the
  // [HttpRequest.headers][google.cloud.tasks.v2beta2.HttpRequest.headers] field
  // will be overridden.
  oneof authorization_header {
    // If specified, an
    // [OAuth token](https://developers.google.com/identity/protocols/OAuth2)
    // will be generated and attached as an `Authorization` header in the HTTP
    // request.
    //
    // This type of authorization should generally only be used when calling
    // Google APIs hosted on *.googleapis.com.
    OAuthToken oauth_token = 5;

    // If specified, an
    // [OIDC](https://developers.google.com/identity/protocols/OpenIDConnect)
    // token will be generated and attached as an `Authorization` header in the
    // HTTP request.
    //
    // This type of authorization can be used for many scenarios, including
    // calling Cloud Run, or endpoints where you intend to validate the token
    // yourself.
    OidcToken oidc_token = 6;
  }
}

// Contains information needed for generating an
// [OAuth token](https://developers.google.com/identity/protocols/OAuth2).
// This type of authorization should generally only be used when calling Google
// APIs hosted on *.googleapis.com.
message OAuthToken {
  // [Service account email](https://cloud.google.com/iam/docs/service-accounts)
  // to be used for generating OAuth token.
  // The service account must be within the same project as the queue. The
  // caller must have iam.serviceAccounts.actAs permission for the service
  // account.
  string service_account_email = 1;

  // OAuth scope to be used for generating OAuth access token.
  // If not specified, "https://www.googleapis.com/auth/cloud-platform"
  // will be used.
  string scope = 2;
}

// Contains information needed for generating an
// [OpenID Connect
// token](https://developers.google.com/identity/protocols/OpenIDConnect).
// This type of authorization can be used for many scenarios, including
// calling Cloud Run, or endpoints where you intend to validate the token
// yourself.
message OidcToken {
  // [Service account email](https://cloud.google.com/iam/docs/service-accounts)
  // to be used for generating OIDC token.
  // The service account must be within the same project as the queue. The
  // caller must have iam.serviceAccounts.actAs permission for the service
  // account.
  string service_account_email = 1;

  // Audience to be used when generating OIDC token. If not specified, the URI
  // specified in target will be used.
  string audience = 2;
}

// The HTTP method used to execute the task.
enum HttpMethod {
  // HTTP method unspecified
  HTTP_METHOD_UNSPECIFIED = 0;

  // HTTP POST
  POST = 1;

  // HTTP GET
  GET = 2;

  // HTTP HEAD
  HEAD = 3;

  // HTTP PUT
  PUT = 4;

  // HTTP DELETE
  DELETE = 5;

  // HTTP PATCH
  PATCH = 6;

  // HTTP OPTIONS
  OPTIONS = 7;
}