DisysExercise1

Group members

Group name: Point of Go return

• Adrian Borup (adbo@itu.dk)
• Andreas Wachs (ahja@itu.dk)
• Anne M. Bartholdy-Falk (anmb@itu.dk)
• Joachim Borup (aljb@itu.dk)

REST Server

To run the server, enter the server folder and run go run .. The server will then be listening at localhost:8080.

Note: the server does not contain actual business logic - i.e. the requests don't actually do anything. It's just a constant response.

REST Client

To run the client, enter the client folder and run go run main.go.

Protocol Buffers

Installation

go get -u github.com/golang/protobuf/{proto,protoc-gen-go}
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

Build IDL for the server

protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative service.proto

Running gRPC with Docker

Build the image

Build the docker image inside the gRPC folder with

docker build -t gogrpc .

Run the container

To spin up the container, run:

# unix
docker run -it --rm -v "$(pwd)":/app --network="host" gogrpc bash
# windows
docker run -it --rm -v ${pwd}:/app --network="host" gogrpc bash

This assumes that you are in the gRPC folder! Note, if your path has spaces, it may very well not work.

Compile Protobuf

cd /app && \
  protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative --experimental_allow_proto3_optional service/service.proto

Run the server

cd /app/server && \
  go run .

Run the client

cd /app/client && \
  go run .

Example output

REST server output

2021/10/03 21:47:39 Server started
2021/10/03 21:47:46 GET /course/1 CourseCourseIdGet 0s
2021/10/03 21:47:46 POST /course CoursePost 0s
2021/10/03 21:47:46 PUT /course/1 CourseCourseIdPut 0s
2021/10/03 21:47:46 DELETE /course/1 CourseCourseIdDelete 0s

REST client output

Requesting [GET] http://127.0.0.1:8080/course/1
{
        "id": 0,
        "name": "string",
        "expectedWorkload": 0,
        "rating": 0
}

Requesting [POST] http://127.0.0.1:8080/course
{
        "id": 0,
        "name": "string",
        "expectedWorkload": 0,
        "rating": 0
}

Requesting [PUT] http://127.0.0.1:8080/course/1
{
        "id": 0,
        "name": "string",
        "expectedWorkload": 0,
        "rating": 0
}

Requesting [DELETE] http://127.0.0.1:8080/course/1
{
        "id": 0,
        "name": "string",
        "expectedWorkload": 0,
        "rating": 0
}

gRPC server output

2021/10/05 10:13:16 NewCourse() call recieved.
2021/10/05 10:13:16 GetCourse() call recieved.
2021/10/05 10:13:16 DeleteCourse() call recieved.
2021/10/05 10:13:16 EditCourse() call recieved.

gRPC client output

2021/10/05 10:13:16 NewCourse: name:"name" expectedWorkload:9000 rating:5
2021/10/05 10:13:16 GetCourse: id:1 name:"name" expectedWorkload:9000 rating:5
2021/10/05 10:13:16 DeleteCourse: id:1 name:"name" expectedWorkload:9000 rating:5
2021/10/05 10:13:16 EditCourse: id:1 name:"Distributed Systems" expectedWorkload:1000000 rating:5