Installation

Install the library into your GOPATH using:

    go get github.com/5Sigma/celerity

A simple API server

Instantiate a server

The core of celerity is the Server. Create a new server using the New function.

svr := celerity.New()

Build a route handler

This RouteHandler is a simple example for an endpoint that says hello to a name passed in the URL.

type HelloResponse struct {
  Message string `json:"message"`
}

func helloHandler (c celerity.Context) celerity.Response {
  name := c.URLParams.String("name")
  r := HelloResponse{ Message: fmt.Sprintf("Hello %s", name)  }
  return c.R(r) 
}

Define the route for the server

Define routing to link a route handler to a URL path. This route will use a URL variable to trap the a url such as /hello/john.

svr.GET("/hello/:name", helloHandler)

Start the server with preconfigured CLI handling

Celerity comes with the ability to roll out nice command line handling for the server; with configurable flags, configuration and environment reading and more. The HandleCLI function accepts a function which returns the server. This allows for some additional configuration when launching the server instance itself.

func main() {
  celerity.HandleCLI(func() *celerity.Server{
    svr := celerity.New()
    return svr
  })
}

Putting it all together

Here is the final code for our server:

import (
  "github.com/5Sigma/celerity"
)

type helloResponse struct {
  Message string `json:"message"`
}

func helloHandler (c celerity.Context) celerity.Response {
  name := c.URLParams.String("name")
  r := helloResponse{ Message: fmt.Sprintf("Hello %s", name)  }
  return c.R(r) 
}

func main() {
  celerity.HandleCLI(func() *celerity.Server {
    svr := celerity.New()
    svr.GET("/hello", helloHandler)
    return svr
  });
}

With this code we can now compile and run our server. Assuming your filename is main.go

go run main.go -- run

Once the server starts you can hit the endpoint you build at:

http://localhost:5000/hello/alice

With its default configuration you should get a JSON response back that resembles:

{
  "requestId":"AE74AB34C12FF4F1A34",
  "success": true,
  "meta": {},
  "data": {
    "message": "Hello alice"
  }
}