Below you will find pages that utilize the taxonomy term “Http”

Posts

Using FauxRPC to debug transcoding HTTP/JSON to gRPC

A Stack overflow question involving transcoding HTTP/JSON to gRPC, piqued my interest. I had a hunch on the solution but was initially dissuaded from attempting a repro because of the complexity:

  1. recreate proto
  2. implement stubs
  3. deploy gRPC-Gateway

I then realized that FauxRPC would probably address much of the complexity and it did.

I created foo.proto:

syntax = "proto3";

import "google/api/annotations.proto";
import "google/api/field_behavior.proto";

import "protoc-gen-openapiv2/options/annotations.proto";

// Was not defined in the question.
service Foo {
    rpc FetchResource(GetResourceRequest) returns (ResourceResponse) {
        option (google.api.http) = {get: "/v1/resource/{resource_id}/group"};
        option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_operation) = {
            summary: "Get Resource from group"
            description: "Retrieve resource info"
        };
    }
};

// Should be named FetchResourceRequest to match the RPC method name.
message GetResourceRequest {
  string resource_id = 1 [
    (google.api.field_behavior) = REQUIRED,
    (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = {
      description: "Resource UUID v4."
      example: "\"81042622-4f02-4e85-a896-172edd5381b6\""
    }
  ];

  ResourceFilter resource_filter = 2 [
    (google.api.field_behavior) = OPTIONAL,
    (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = {
      description: "\"RESOURCE_FILTER_FIRST\""
    }
  ];
}

// Empty response for demonstration purposes.
// Was not defined in the question.
// Should be named FetchResourceResponse to match the RPC method name.
message ResourceResponse {}

enum ResourceFilter {
  option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_enum) = {
    title: "Resource Filter"
    example: "\"RESOURCE_FILTER_FIRST\""
  };
  RESOURCE_FILTER_UNSPECIFIED = 0;
  RESOURCE_FILTER_FIRST = 1;
}

The proto depends on googleapis (Google’s repo containing definitions for Google’s services) and grpc-gateway (containing protoc plugins and protobuf sources).

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Posts

Multiplexing gRPC and HTTP (Prometheus) endpoints with Cloud Run

Google Cloud Run is useful but, each service is limited to exposing a single port. This caused me problems with a gRPC service that serves (non-gRPC) Prometheus metrics because customarily, you would serve gRPC on one port and the Prometheus metrics on another.

Fortunately, cmux provides a solution by providing a mechanism that multiplexes both services (gRPC and HTTP) on a single port!

TL;DR See the cmux Limitations and use:

grpcl := m.MatchWithWriters(
   cmux.HTTP2MatchHeaderFieldSendSettings("content-type", "application/grpc"))

Extending the example from the cmux repo:

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