gRPC + Django Integration with RESTart: gRPC Book Service

gRPC Integration with Django.

This project uses internal automation and build tools. The concerned files and folders in project are:

• grpc_protos
• grpc_utils
• grpc_rest

The Django Application in this project is basic skeleton without serializers, urls and build files. It contains views and it's implementation which we will be using in grpc_services.

Setup virtualenv

pip install virtualenv
virtualenv .venv

Install requirements

$ pip install -r requirements.txt
$ pip install googleapis-common-protos
# if you ran into any issue with kerbrose package install below system dependencies
$ sudo apt-get install krb5-config libkrb5-dev libssl-dev libsasl2-dev libsasl2-modules-gssapi-mit

Running django management commands & usage

$ source .venv/bin/activate
$ export DJANGO_SETTINGS_MODULE=grpc_book_service_backend.settings.local

# Internal Tools
$ python manage.py build -a grpc_book_service # generate build files
$ python manage.py build -p grpc_book_service # generate protobuf

$ python manage.py makemigrations
$ python manage.py migrate

Running gRPC Server:

$ python manage.py generate_grpc_stubs grpc_book_service/grpc_protos app.proto

# If importing google.api.annotations:
$ python -m grpc_tools.protoc -I grpc_book_service/grpc_protos --python_out=./grpc_book_service/grpc_protos --grpc_python_out=./grpc_book_service/grpc_protos -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis grpc_book_service/grpc_protos/app.proto

# Start gRPC Server
$ python manage.py run_grpc_server grpc_book_service

Running REST Server with gRPC:

This is a way with golang http reverse proxy gateway mentioned at https://github.com/grpc-ecosystem/grpc-gateway

# GoLang Gateway out: 
$ protoc -I/usr/local/include -I. -I./grpc_book_service/grpc_protos -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis --grpc-gateway_out=logtostderr=true:. ./grpc_book_service/grpc_protos/app.proto

Another way using https://github.com/RussellLuo/grpc-pytools/

# Generate AST File
$ python -m grpc_tools.protoc -I. --pytools-ast_out=grpc_book_service/grpc_rest/app_ast.json grpc_book_service/grpc_protos/app.proto

# Generate Pythonic Services based on Flask
$ python -m grpc_pytools.pythonic --proto-ast-file=grpc_book_service/grpc_protos/app_ast.json --pb2-module-name=grpc_book_service/grpc_protos/app_pb2 > grpc_book_service/grpc_rest/services.py

# Generate Marshmallow Schemas
$ python -m grpc_pytools.marshmallow --proto-ast-file=grpc_book_service/grpc_protos/app_ast.json --pb2-module-name=grpc_book_service/grpc_protos/app_pb2 > grpc_book_service/grpc_rest/schemas.py

# Generate RESTart APIs
$ python -m grpc_pytools.restart --proto-ast-file=grpc_book_service/grpc_protos/app_ast.json --pb2-module-name=grpc_book_service/grpc_protos/app_pb2 --grpc-server=localhost:50051 > grpc_book_service/grpc_rest/apis.py
# Modify the api path in <grpc_book_service/grpc_rest/apis.py> as per OpenAPI Spec

# Run the HTTP/1.1 server
$ restart grpc_book_service.grpc_rest.apis:api -p 60066

# Try cURL
$ curl -i -H 'Content-Type: application/json' -X POST http://localhost:60066/grpc_book_service/get_book_post -d '{"isbn": 1}'

Connecting to GRPC Using ServiceClient

from grpc_book_service.grpc_protos import app_pb2, app_pb2_grpc
from grpc_book_service.grpc_utils.service_client import ServiceClient
books_service_client = ServiceClient(app_pb2_grpc, 'GRPCBookServiceStub', 'localhost', 50051)
response = books_service_client.GetBookPost(app_pb2.GetBookRequest(isbn=1))

# <response:>
# isbn: 1
# name: "NW-Novel"
# author: "Hiroko Murakami"
# title: "Norwegian Wood"
# codes: 1.0
# codes: 2.5
# codes: 5.5

The project also has helper modules from following repos, packages and blogs:

• https://pypi.org/project/grpc-django/
• http://flagzeta.org/blog/using-grpc-with-django/
• https://github.com/grpc-ecosystem/grpc-gateway
• https://github.com/RussellLuo/grpc-pytools
• https://grpc.io/docs/quickstart/python.html