gRPC Experiment

• An experiment with gRPC http://www.grpc.io/
• useful for learning gRPC https://github.com/kelseyhightower/grpc-hello-service

Compiling and Running

Service Definitions and Protobufs

• Services and messages are defined in protobuf/...
• If needed then recompile the Go libraries from the protobuf definitions.
• Prerequisites from http://www.grpc.io/docs/quickstart/go.html

protoc --proto_path=protobuf/field/ --go_out=plugins=grpc:field protobuf/field/*
protoc --proto_path=protobuf/data/ --go_out=plugins=grpc:data protobuf/data/*

Server

• Simple token based auth.
• Interceptor for metrics.
• Auth requires end-to-end TLS encryption.
• Reads TLS cert from certs/server.crt and cert/server.key otherwise a self signed TLS cert is generated on the fly.
• A self signed cert can be generated using:

openssl genrsa -out server.key 2048
openssl req -new -x509 -key server.key -out server.crt -days 3650

• It's possible to handle gRPC and HTTP in the same server see https://coreos.com/blog/gRPC-protobufs-swagger.html

Integration tests for the server:

cd mtr-api
export $(cat env.list | grep = | xargs); go test -v

Build and run the server:

cd mtr-api
export $(cat env.list | grep = | xargs); go build && ./mtr-api

Docker

• Build an image with ./build.sh mtr-api
• Run the container. Self signed TLS certificates will be created on the fly.

docker run --env-file mtr-api/env.list -p 8443:8443 quay.io/gclitheroe/mtr-api:latest

• Mount a volume with TLS certificates into the container.

docker run --env-file mtr-api/env.list -p 8443:8443 -v /work/certs:/certs quay.io/gclitheroe/mtr-api:latest

Client

• Build and run the client.
• Server will log messages.
• Client reconnects after server restarts.

cd mtr-client
export $(cat env.list | grep = | xargs); go build && ./mtr-client