pyease-grpc 1.5.0

Easy gRPC-web client in python

pyease-grpc

Easy to use gRPC-web client in python

Tutorial

This package provides a requests like interface to make calls to gRPC-Web servers.

Installation

Install the package using:

$ pip install pyease-grpc

Run the following to check if it has been installed correctly:

$ pyease-grpc --version

Introduction

You need to have a basic understanding of how gRPC works.

An example server and client can be found in the example folder. To run the server you need to have docker installed.

> cd example
> docker compose up

It runs a grpc server and creates an envoy proxy for grpc-web access.

The grpc server address: localhost:50050 The envoy proxy address: http://localhost:8080

Now let's check the example/server folder for the abc.proto file:

// file: example/server/abc.proto
syntax = "proto3";

package pyease.sample.v1;

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloResponse);
  rpc LotsOfReplies(HelloRequest) returns (stream HelloResponse);
  rpc LotsOfGreetings(stream HelloRequest) returns (HelloResponse);
  rpc BidiHello(stream HelloRequest) returns (stream HelloResponse);
}

message HelloRequest {
  string name = 1;
}

message HelloResponse {
  string reply = 1;
}

To make a request to SayHello:

from pyease_grpc import Protobuf, RpcSession, RpcUri

protobuf = Protobuf.from_file("example/server/abc.proto")
session = RpcSession(protobuf)

response = session.request(
    RpcUri(
      "http://localhost:8080",
      package="pyease.sample.v1",
      service="Greeter",
      method="SayHello",
    ),
    {
      "name": "world"
    },
)
response.raise_for_status()

result = response.single
print(result['reply'])

The session.request accepts request data as a dict and returns the response as a dict.

gRPC-web currently supports 2 RPC modes: Unary RPCs, Server-side Streaming RPCs. Client-side and Bi-directional streaming is not currently supported.

Source: https://github.com/grpc/grpc-web#streaming-support

Descriptor

The FileDescriptorSet is the faster way to load Protobuf.

To generate FileDescriptorSet as json:

$ pyease-grpc -I example/server example/server/abc.proto --output abc_fds.json

Now you can use this descriptor file directly to create a Protobuf instance.

# Use the descriptor directly to create protobuf instance
protobuf = Protobuf.restore_file('abc_fds.json')

# You can even create the session directly from descriptor
session = RpcSession.from_descriptor(descriptor)