text: // Copyright 2019 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.api;
  
  option go_package = "google.golang.org/genproto/googleapis/api/serviceconfig;serviceconfig";
  option java_multiple_files = true;
  option java_outer_classname = "BackendProto";
  option java_package = "com.google.api";
  option objc_class_prefix = "GAPI";
  
  // `Backend` defines the backend configuration for a service.
  message Backend {
    // A list of API backend rules that apply to individual API methods.
    //
    // **NOTE:** All service configuration rules follow "last one wins" order.
    repeated BackendRule rules = 1;
  }
  
  // A backend rule provides configuration for an individual API element.
  message BackendRule {
    // Path Translation specifies how to combine the backend address with the
    // request path in order to produce the appropriate forwarding URL for the
    // request.
    //
    // Path Translation is applicable only to HTTP-based backends. Backends which
    // do not accept requests over HTTP/HTTPS should leave `path_translation`
    // unspecified.
    enum PathTranslation {
      PATH_TRANSLATION_UNSPECIFIED = 0;
  
      // Use the backend address as-is, with no modification to the path. If the
      // URL pattern contains variables, the variable names and values will be
      // appended to the query string. If a query string parameter and a URL
      // pattern variable have the same name, this may result in duplicate keys in
      // the query string.
      //
      // # Examples
      //
      // Given the following operation config:
      //
      //     Method path:        /api/company/{cid}/user/{uid}
      //     Backend address:    https://example.cloudfunctions.net/getUser
      //
      // Requests to the following request paths will call the backend at the
      // translated path:
      //
      //     Request path: /api/company/widgetworks/user/johndoe
      //     Translated:
      //     https://example.cloudfunctions.net/getUser?cid=widgetworks&uid=johndoe
      //
      //     Request path: /api/company/widgetworks/user/johndoe?timezone=EST
      //     Translated:
      //     https://example.cloudfunctions.net/getUser?timezone=EST&cid=widgetworks&uid=johndoe
      CONSTANT_ADDRESS = 1;
  
      // The request path will be appended to the backend address.
      //
      // # Examples
      //
      // Given the following operation config:
      //
      //     Method path:        /api/company/{cid}/user/{uid}
      //     Backend address:    https://example.appspot.com
      //
      // Requests to the following request paths will call the backend at the
      // translated path:
      //
      //     Request path: /api/company/widgetworks/user/johndoe
      //     Translated:
      //     https://example.appspot.com/api/company/widgetworks/user/johndoe
      //
      //     Request path: /api/company/widgetworks/user/johndoe?timezone=EST
      //     Translated:
      //     https://example.appspot.com/api/company/widgetworks/user/johndoe?timezone=EST
      APPEND_PATH_TO_ADDRESS = 2;
    }
  
    // Selects the methods to which this rule applies.
    //
    // Refer to [selector][google.api.DocumentationRule.selector] for syntax details.
    string selector = 1;
  
    // The address of the API backend.
    string address = 2;
  
    // The number of seconds to wait for a response from a request.  The default
    // deadline for gRPC is infinite (no deadline) and HTTP requests is 5 seconds.
    double deadline = 3;
  
    // Minimum deadline in seconds needed for this method. Calls having deadline
    // value lower than this will be rejected.
    double min_deadline = 4;
  
    // The number of seconds to wait for the completion of a long running
    // operation. The default is no deadline.
    double operation_deadline = 5;
  
    PathTranslation path_translation = 6;
  
    // Authentication settings used by the backend.
    //
    // These are typically used to provide service management functionality to
    // a backend served on a publicly-routable URL. The `authentication`
    // details should match the authentication behavior used by the backend.
    //
    // For example, specifying `jwt_audience` implies that the backend expects
    // authentication via a JWT.
    oneof authentication {
      // The JWT audience is used when generating a JWT id token for the backend.
      string jwt_audience = 7;
    }
  }
  