Permalink
371 lines (352 sloc) 14.8 KB
// Copyright 2018 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 cc_enable_arenas = true;
option go_package = "google.golang.org/genproto/googleapis/api/annotations;annotations";
option java_multiple_files = true;
option java_outer_classname = "HttpProto";
option java_package = "com.google.api";
option objc_class_prefix = "GAPI";
// Defines the HTTP configuration for an API service. It contains a list of
// [HttpRule][google.api.HttpRule], each specifying the mapping of an RPC method
// to one or more HTTP REST API methods.
message Http {
// A list of HTTP configuration rules that apply to individual API methods.
//
// **NOTE:** All service configuration rules follow "last one wins" order.
repeated HttpRule rules = 1;
// When set to true, URL path parmeters will be fully URI-decoded except in
// cases of single segment matches in reserved expansion, where "%2F" will be
// left encoded.
//
// The default behavior is to not decode RFC 6570 reserved characters in multi
// segment matches.
bool fully_decode_reserved_expansion = 2;
}
// # gRPC Transcoding
//
// gRPC Transcoding is a feature for mapping between a gRPC method and one or
// more HTTP REST endpoints. It allows developers to build a single API service
// that supports both gRPC APIs and REST APIs. Many systems, including [Google
// APIs](https://github.com/googleapis/googleapis),
// [Cloud Endpoints](https://cloud.google.com/endpoints), [gRPC
// Gateway](https://github.com/grpc-ecosystem/grpc-gateway),
// and [Envoy](https://github.com/envoyproxy/envoy) proxy support this feature
// and use it for large scale production services.
//
// `HttpRule` defines the schema of the gRPC/REST mapping. The mapping specifies
// how different portions of the gRPC request message are mapped to the URL
// path, URL query parameters, and HTTP request body. It also controls how the
// gRPC response message is mapped to the HTTP response body. `HttpRule` is
// typically specified as an `google.api.http` annotation on the gRPC method.
//
// Each mapping specifies a URL path template and an HTTP method. The path
// template may refer to one or more fields in the gRPC request message, as long
// as each field is a non-repeated field with a primitive (non-message) type.
// The path template controls how fields of the request message are mapped to
// the URL path.
//
// Example:
//
// service Messaging {
// rpc GetMessage(GetMessageRequest) returns (Message) {
// option (google.api.http) = {
// get: "/v1/{name=messages/*"}"
// };
// }
// }
// message GetMessageRequest {
// string name = 1; // Mapped to URL path.
// }
// message Message {
// string text = 1; // The resource content.
// }
//
// This enables an HTTP REST to gRPC mapping as below:
//
// HTTP | gRPC
// -----|-----
// `GET /v1/messages/123456` | `GetMessage(name: "messages/123456")`
//
// Any fields in the request message which are not bound by the path template
// automatically become HTTP query parameters if there is no HTTP request body.
// For example:
//
// service Messaging {
// rpc GetMessage(GetMessageRequest) returns (Message) {
// option (google.api.http) = {
// get:"/v1/messages/{message_id}"
// };
// }
// }
// message GetMessageRequest {
// message SubMessage {
// string subfield = 1;
// }
// string message_id = 1; // Mapped to URL path.
// int64 revision = 2; // Mapped to URL query parameter `revision`.
// SubMessage sub = 3; // Mapped to URL query parameter `sub.subfield`.
// }
//
// This enables a HTTP JSON to RPC mapping as below:
//
// HTTP | gRPC
// -----|-----
// `GET /v1/messages/123456?revision=2&sub.subfield=foo` | `GetMessage(message_id: "123456" revision: 2 sub: SubMessage(subfield: "foo"))`
//
// Note that fields which are mapped to URL query parameters must have a
// primitive type or a repeated primitive type or a non-repeated message type.
// In the case of a repeated type, the parameter can be repeated in the URL
// as `...?param=A&param=B`. In the case of a message type, each field of the
// message is mapped to a separate parameter, such as
// `...?foo.a=A&foo.b=B&foo.c=C`.
//
// For HTTP methods that allow a request body, the `body` field
// specifies the mapping. Consider a REST update method on the
// message resource collection:
//
// service Messaging {
// rpc UpdateMessage(UpdateMessageRequest) returns (Message) {
// option (google.api.http) = {
// patch: "/v1/messages/{message_id}"
// body: "message"
// };
// }
// }
// message UpdateMessageRequest {
// string message_id = 1; // mapped to the URL
// Message message = 2; // mapped to the body
// }
//
// The following HTTP JSON to RPC mapping is enabled, where the
// representation of the JSON in the request body is determined by
// protos JSON encoding:
//
// HTTP | gRPC
// -----|-----
// `PATCH /v1/messages/123456 { "text": "Hi!" }` | `UpdateMessage(message_id: "123456" message { text: "Hi!" })`
//
// The special name `*` can be used in the body mapping to define that
// every field not bound by the path template should be mapped to the
// request body. This enables the following alternative definition of
// the update method:
//
// service Messaging {
// rpc UpdateMessage(Message) returns (Message) {
// option (google.api.http) = {
// patch: "/v1/messages/{message_id}"
// body: "*"
// };
// }
// }
// message Message {
// string message_id = 1;
// string text = 2;
// }
//
//
// The following HTTP JSON to RPC mapping is enabled:
//
// HTTP | gRPC
// -----|-----
// `PATCH /v1/messages/123456 { "text": "Hi!" }` | `UpdateMessage(message_id: "123456" text: "Hi!")`
//
// Note that when using `*` in the body mapping, it is not possible to
// have HTTP parameters, as all fields not bound by the path end in
// the body. This makes this option more rarely used in practice when
// defining REST APIs. The common usage of `*` is in custom methods
// which don't use the URL at all for transferring data.
//
// It is possible to define multiple HTTP methods for one RPC by using
// the `additional_bindings` option. Example:
//
// service Messaging {
// rpc GetMessage(GetMessageRequest) returns (Message) {
// option (google.api.http) = {
// get: "/v1/messages/{message_id}"
// additional_bindings {
// get: "/v1/users/{user_id}/messages/{message_id}"
// }
// };
// }
// }
// message GetMessageRequest {
// string message_id = 1;
// string user_id = 2;
// }
//
// This enables the following two alternative HTTP JSON to RPC mappings:
//
// HTTP | gRPC
// -----|-----
// `GET /v1/messages/123456` | `GetMessage(message_id: "123456")`
// `GET /v1/users/me/messages/123456` | `GetMessage(user_id: "me" message_id: "123456")`
//
// ## Rules for HTTP mapping
//
// 1. Leaf request fields (recursive expansion nested messages in the request
// message) are classified into three categories:
// - Fields referred by the path template. They are passed via the URL path.
// - Fields referred by the [HttpRule.body][google.api.HttpRule.body]. They are passed via the HTTP
// request body.
// - All other fields are passed via the URL query parameters, and the
// parameter name is the field path in the request message. A repeated
// field can be represented as multiple query parameters under the same
// name.
// 2. If [HttpRule.body][google.api.HttpRule.body] is "*", there is no URL query parameter, all fields
// are passed via URL path and HTTP request body.
// 3. If [HttpRule.body][google.api.HttpRule.body] is omitted, there is no HTTP request body, all
// fields are passed via URL path and URL query parameters.
//
// ### Path template syntax
//
// Template = "/" Segments [ Verb ] ;
// Segments = Segment { "/" Segment } ;
// Segment = "*" | "**" | LITERAL | Variable ;
// Variable = "{" FieldPath [ "=" Segments ] "}" ;
// FieldPath = IDENT { "." IDENT } ;
// Verb = ":" LITERAL ;
//
// The syntax `*` matches a single URL path segment. The syntax `**` matches
// zero or more URL path segments, which must be the last part of the URL path
// except the `Verb`.
//
// The syntax `Variable` matches part of the URL path as specified by its
// template. A variable template must not contain other variables. If a variable
// matches a single path segment, its template may be omitted, e.g. `{var}`
// is equivalent to `{var=*}`.
//
// The syntax `LITERAL` matches literal text in the URL path. If the `LITERAL`
// contains any reserved character, such characters should be percent-encoded
// before the matching.
//
// If a variable contains exactly one path segment, such as `"{var}"` or
// `"{var=*}"`, when such a variable is expanded into a URL path on the client
// side, all characters except `[-_.~0-9a-zA-Z]` are percent-encoded. The
// server side does the reverse decoding. Such variables show up in the
// [Discovery Document](https://developers.google.com/discovery/v1/reference/apis)
// as `{var}`.
//
// If a variable contains multiple path segments, such as `"{var=foo/*}"`
// or `"{var=**}"`, when such a variable is expanded into a URL path on the
// client side, all characters except `[-_.~/0-9a-zA-Z]` are percent-encoded.
// The server side does the reverse decoding, except "%2F" and "%2f" are left
// unchanged. Such variables show up in the
// [Discovery Document](https://developers.google.com/discovery/v1/reference/apis)
// as `{+var}`.
//
// ## Using gRPC API Service Configuration
//
// gRPC API Service Configuration (service config) is a configuration language
// for configuring a gRPC service to become a user-facing product. The
// service config is simply the YAML representation of the `google.api.Service`
// proto message.
//
// As an alternative to annotating your proto file, you can configure gRPC
// transcoding in your service config YAML files. You do this by specifying a
// `HttpRule` that maps the gRPC method to a REST endpoint, achieving the same
// effect as the proto annotation. This can be particularly useful if you
// have a proto that is reused in multiple services. Note that any transcoding
// specified in the service config will override any matching transcoding
// configuration in the proto.
//
// Example:
//
// http:
// rules:
// # Selects a gRPC method and applies HttpRule to it.
// - selector: example.v1.Messaging.GetMessage
// get: /v1/messages/{message_id}/{sub.subfield}
//
// ## Special notes
//
// When gRPC Transcoding is used to map a gRPC to JSON REST endpoints, the
// proto to JSON conversion must follow the [proto3
// specification](https://developers.google.com/protocol-buffers/docs/proto3#json).
//
// While the single segment variable follows the semantics of
// [RFC 6570](https://tools.ietf.org/html/rfc6570) Section 3.2.2 Simple String
// Expansion, the multi segment variable **does not** follow RFC 6570 Section
// 3.2.3 Reserved Expansion. The reason is that the Reserved Expansion
// does not expand special characters like `?` and `#`, which would lead
// to invalid URLs. As the result, gRPC Transcoding uses a custom encoding
// for multi segment variables.
//
// The path variables **must not** refer to any repeated or mapped field,
// because client libraries are not capable of handling such variable expansion.
//
// The path variables **must not** capture the leading "/" character. The reason
// is that the most common use case "{var}" does not capture the leading "/"
// character. For consistency, all path variables must share the same behavior.
//
// Repeated message fields must not be mapped to URL query parameters, because
// no client library can support such complicated mapping.
//
// If an API needs to use a JSON array for request or response body, it can map
// the request or response body to a repeated field. However, some gRPC
// Transcoding implementations may not support this feature.
message HttpRule {
// Selects a method to which this rule applies.
//
// Refer to [selector][google.api.DocumentationRule.selector] for syntax details.
string selector = 1;
// Determines the URL pattern is matched by this rules. This pattern can be
// used with any of the {get|put|post|delete|patch} methods. A custom method
// can be defined using the 'custom' field.
oneof pattern {
// Maps to HTTP GET. Used for listing and getting information about
// resources.
string get = 2;
// Maps to HTTP PUT. Used for replacing a resource.
string put = 3;
// Maps to HTTP POST. Used for creating a resource or performing an action.
string post = 4;
// Maps to HTTP DELETE. Used for deleting a resource.
string delete = 5;
// Maps to HTTP PATCH. Used for updating a resource.
string patch = 6;
// The custom pattern is used for specifying an HTTP method that is not
// included in the `pattern` field, such as HEAD, or "*" to leave the
// HTTP method unspecified for this rule. The wild-card rule is useful
// for services that provide content to Web (HTML) clients.
CustomHttpPattern custom = 8;
}
// The name of the request field whose value is mapped to the HTTP request
// body, or `*` for mapping all request fields not captured by the path
// pattern to the HTTP body, or omitted for not having any HTTP request body.
//
// NOTE: the referred field must be present at the top-level of the request
// message type.
string body = 7;
// Optional. The name of the response field whose value is mapped to the HTTP
// response body. When omitted, the entire response message will be used
// as the HTTP response body.
//
// NOTE: The referred field must be present at the top-level of the response
// message type.
string response_body = 12;
// Additional HTTP bindings for the selector. Nested bindings must
// not contain an `additional_bindings` field themselves (that is,
// the nesting may only be one level deep).
repeated HttpRule additional_bindings = 11;
}
// A custom pattern is used for defining custom HTTP verb.
message CustomHttpPattern {
// The name of this custom HTTP verb.
string kind = 1;
// The path matched by this custom verb.
string path = 2;
}