jaschweder/go-http-mock-server repository overview

{
    "server":{
        "address":"0.0.0.0",
        "port":8080
    },
    "routes":[
        {
            "request":{
                "method":"GET",
                "url":"/hello"
            },
            "response":{
                "status":200,
                "body":"{\"message\": \"World!\"}"
            }
        }
    ]
}

$ gomock mock.json

$ curl http://localhost:8080/hello
{message: "World!"}