feat(types): Add gRPC Richer Error Model support (BadRequest) (#1068)

* types: add tonic as dependency, add error_details.proto

* types: add BadRequest support from flemosr/tonic-richer-error

* types: adjust code following suggestions

Adjustments following suggestions by @LucioFranco in #1068.

Adjust style, remove unecessary prints, avoid glob imports, apply
`non_exhaustive` to `ErrorDetails` and `ErrorDetail`, avoid pub
fields in `ErrorDetails`, adjust
`WithErrorDetails::with_error_details_vec` args, add
`gen_details_bytes`.

* types: add generated protobuf code

As suggested by @LucioFranco in #1068 (comment).

This avoids the need for consumers to have `protoc` in their path.
Implemented following changes in #1065.

* types: add custom metadata support

This allows consumers to provide custom metadata when creating a
`Status` with error details.

* types: adjust code following suggestions

Adjustments following suggestions by @LucioFranco in #1068.

Move `error_details_vec` mod into `error_details` mod, adjust doc
comments, rename `WithErrorDetails` trait to `StatusExt`.

tonic-types/Cargo.toml

@@ -17,6 +17,7 @@ version = "0.6.0"
 [dependencies]
 prost = "0.11"
 prost-types = "0.11"
+tonic = {version = "0.8", path = "../tonic"}
 
-[build-dependencies]
-prost-build = "0.11"
+[dev-dependencies]
+tonic-build = {version = "0.8", path = "../tonic-build", features = ["prost"]}

tonic-types/proto/error_details.proto

@@ -0,0 +1,250 @@
+// Copyright 2020 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.rpc;
+
+import "google/protobuf/duration.proto";
+
+option go_package = "google.golang.org/genproto/googleapis/rpc/errdetails;errdetails";
+option java_multiple_files = true;
+option java_outer_classname = "ErrorDetailsProto";
+option java_package = "com.google.rpc";
+option objc_class_prefix = "RPC";
+
+// Describes when the clients can retry a failed request. Clients could ignore
+// the recommendation here or retry when this information is missing from error
+// responses.
+//
+// It's always recommended that clients should use exponential backoff when
+// retrying.
+//
+// Clients should wait until `retry_delay` amount of time has passed since
+// receiving the error response before retrying.  If retrying requests also
+// fail, clients should use an exponential backoff scheme to gradually increase
+// the delay between retries based on `retry_delay`, until either a maximum
+// number of retries have been reached or a maximum retry delay cap has been
+// reached.
+message RetryInfo {
+  // Clients should wait at least this long between retrying the same request.
+  google.protobuf.Duration retry_delay = 1;
+}
+
+// Describes additional debugging info.
+message DebugInfo {
+  // The stack trace entries indicating where the error occurred.
+  repeated string stack_entries = 1;
+
+  // Additional debugging information provided by the server.
+  string detail = 2;
+}
+
+// Describes how a quota check failed.
+//
+// For example if a daily limit was exceeded for the calling project,
+// a service could respond with a QuotaFailure detail containing the project
+// id and the description of the quota limit that was exceeded.  If the
+// calling project hasn't enabled the service in the developer console, then
+// a service could respond with the project id and set `service_disabled`
+// to true.
+//
+// Also see RetryInfo and Help types for other details about handling a
+// quota failure.
+message QuotaFailure {
+  // A message type used to describe a single quota violation.  For example, a
+  // daily quota or a custom quota that was exceeded.
+  message Violation {
+    // The subject on which the quota check failed.
+    // For example, "clientip:<ip address of client>" or "project:<Google
+    // developer project id>".
+    string subject = 1;
+
+    // A description of how the quota check failed. Clients can use this
+    // description to find more about the quota configuration in the service's
+    // public documentation, or find the relevant quota limit to adjust through
+    // developer console.
+    //
+    // For example: "Service disabled" or "Daily Limit for read operations
+    // exceeded".
+    string description = 2;
+  }
+
+  // Describes all quota violations.
+  repeated Violation violations = 1;
+}
+
+// Describes the cause of the error with structured details.
+//
+// Example of an error when contacting the "pubsub.googleapis.com" API when it
+// is not enabled:
+// ```json
+//     { "reason": "API_DISABLED"
+//       "domain": "googleapis.com"
+//       "metadata": {
+//         "resource": "projects/123",
+//         "service": "pubsub.googleapis.com"
+//       }
+//     }
+// ```
+// This response indicates that the pubsub.googleapis.com API is not enabled.
+//
+// Example of an error that is returned when attempting to create a Spanner
+// instance in a region that is out of stock:
+// ```json
+//     { "reason": "STOCKOUT"
+//       "domain": "spanner.googleapis.com",
+//       "metadata": {
+//         "availableRegions": "us-central1,us-east2"
+//       }
+//     }
+// ```
+message ErrorInfo {
+  // The reason of the error. This is a constant value that identifies the
+  // proximate cause of the error. Error reasons are unique within a particular
+  // domain of errors. This should be at most 63 characters and match
+  // /[A-Z0-9_]+/.
+  string reason = 1;
+
+  // The logical grouping to which the "reason" belongs. The error domain
+  // is typically the registered service name of the tool or product that
+  // generates the error. Example: "pubsub.googleapis.com". If the error is
+  // generated by some common infrastructure, the error domain must be a
+  // globally unique value that identifies the infrastructure. For Google API
+  // infrastructure, the error domain is "googleapis.com".
+  string domain = 2;
+
+  // Additional structured details about this error.
+  //
+  // Keys should match /[a-zA-Z0-9-_]/ and be limited to 64 characters in
+  // length. When identifying the current value of an exceeded limit, the units
+  // should be contained in the key, not the value.  For example, rather than
+  // {"instanceLimit": "100/request"}, should be returned as,
+  // {"instanceLimitPerRequest": "100"}, if the client exceeds the number of
+  // instances that can be created in a single (batch) request.
+  map<string, string> metadata = 3;
+}
+
+// Describes what preconditions have failed.
+//
+// For example, if an RPC failed because it required the Terms of Service to be
+// acknowledged, it could list the terms of service violation in the
+// PreconditionFailure message.
+message PreconditionFailure {
+  // A message type used to describe a single precondition failure.
+  message Violation {
+    // The type of PreconditionFailure. We recommend using a service-specific
+    // enum type to define the supported precondition violation subjects. For
+    // example, "TOS" for "Terms of Service violation".
+    string type = 1;
+
+    // The subject, relative to the type, that failed.
+    // For example, "google.com/cloud" relative to the "TOS" type would indicate
+    // which terms of service is being referenced.
+    string subject = 2;
+
+    // A description of how the precondition failed. Developers can use this
+    // description to understand how to fix the failure.
+    //
+    // For example: "Terms of service not accepted".
+    string description = 3;
+  }
+
+  // Describes all precondition violations.
+  repeated Violation violations = 1;
+}
+
+// Describes violations in a client request. This error type focuses on the
+// syntactic aspects of the request.
+message BadRequest {
+  // A message type used to describe a single bad request field.
+  message FieldViolation {
+    // A path leading to a field in the request body. The value will be a
+    // sequence of dot-separated identifiers that identify a protocol buffer
+    // field. E.g., "field_violations.field" would identify this field.
+    string field = 1;
+
+    // A description of why the request element is bad.
+    string description = 2;
+  }
+
+  // Describes all violations in a client request.
+  repeated FieldViolation field_violations = 1;
+}
+
+// Contains metadata about the request that clients can attach when filing a bug
+// or providing other forms of feedback.
+message RequestInfo {
+  // An opaque string that should only be interpreted by the service generating
+  // it. For example, it can be used to identify requests in the service's logs.
+  string request_id = 1;
+
+  // Any data that was used to serve this request. For example, an encrypted
+  // stack trace that can be sent back to the service provider for debugging.
+  string serving_data = 2;
+}
+
+// Describes the resource that is being accessed.
+message ResourceInfo {
+  // A name for the type of resource being accessed, e.g. "sql table",
+  // "cloud storage bucket", "file", "Google calendar"; or the type URL
+  // of the resource: e.g. "type.googleapis.com/google.pubsub.v1.Topic".
+  string resource_type = 1;
+
+  // The name of the resource being accessed.  For example, a shared calendar
+  // name: "example.com_4fghdhgsrgh@group.calendar.google.com", if the current
+  // error is [google.rpc.Code.PERMISSION_DENIED][google.rpc.Code.PERMISSION_DENIED].
+  string resource_name = 2;
+
+  // The owner of the resource (optional).
+  // For example, "user:<owner email>" or "project:<Google developer project
+  // id>".
+  string owner = 3;
+
+  // Describes what error is encountered when accessing this resource.
+  // For example, updating a cloud project may require the `writer` permission
+  // on the developer console project.
+  string description = 4;
+}
+
+// Provides links to documentation or for performing an out of band action.
+//
+// For example, if a quota check failed with an error indicating the calling
+// project hasn't enabled the accessed service, this can contain a URL pointing
+// directly to the right place in the developer console to flip the bit.
+message Help {
+  // Describes a URL link.
+  message Link {
+    // Describes what the link offers.
+    string description = 1;
+
+    // The URL of the link.
+    string url = 2;
+  }
+
+  // URL(s) pointing to additional information on handling the current error.
+  repeated Link links = 1;
+}
+
+// Provides a localized error message that is safe to return to the user
+// which can be attached to an RPC error.
+message LocalizedMessage {
+  // The locale used following the specification defined at
+  // http://www.rfc-editor.org/rfc/bcp/bcp47.txt.
+  // Examples are: "en-US", "fr-CH", "es-MX"
+  string locale = 1;
+
+  // The localized error message in the above locale.
+  string message = 2;
+}