mediary

README

mediary

Add interceptors to http.Client and you will be able to

• Dump request and/or response to a Log
• Alter your requests before they are sent or responses before they are returned
• Add Tracing information using Opentracing/Jaeger
• Send metrics to statsd

All this and more while using a "regular" http.Client

Usage

var client *http.Client
client = mediary.Init().AddInterceptors(your interceptor).Build()
client.Get("https://golang.org")

Dump Example

client := mediary.Init().AddInterceptors(dumpInterceptor).Build()
client.Get("https://golang.org")

func dumpInterceptor(req *http.Request, handler mediary.Handler) (*http.Response, error) {
	if bytes, err := httputil.DumpRequestOut(req, true); err == nil {
		fmt.Printf("%s", bytes)

		//GET / HTTP/1.1
		//Host: golang.org
		//User-Agent: Go-http-client/1.1
		//Accept-Encoding: gzip
	}
	return handler(req)
}

Interceptor

Interceptor is a function

type Interceptor func(*http.Request, Handler) (*http.Response, error)

Handler is just an alias to http.Roundtripper function called RoundTrip

type Handler func(*http.Request) (*http.Response, error)

Multiple interceptors

It's possible to chain interceptors

client := mediary.Init().
    AddInterceptors(First Interceptor, Second Interceptor).
    AddInterceptors(Third Interceptor).
    Build()

This is how it actually works

• First Intereptor: Request
  • Second Interceptor: Request
    • Third Interceptor: Request
      • Handler <-- Actual http call
    • Third Interceptor: Response
  • Second Interceptor: Response
• First Interceptor: Response

Using custom client/transport

If you already have a pre-configured http.Client you can use it as well

yourClient := &http.Client{}
yourClientWithInterceptor := mediary.Init().
    WithPreconfiguredClient(yourClient).
    AddInterceptors(your interceptor).
    Build()

Read this for more information

Documentation

Index

• type Builder
  • func Init() Builder
• type Handler
• type Interceptor

Types

type Builder

type Builder interface {
	AddInterceptors(...Interceptor) Builder
	WithPreconfiguredClient(*http.Client) Builder
	Build() *http.Client
}

Builder is a builder interface to help guide and create a mediary instance

func Init

func Init() Builder

Init initializes mediary instance configuration

type Handler

type Handler func(*http.Request) (*http.Response, error)

Handler is just an alias to http.RoundTriper.RoundTrip function

type Interceptor

type Interceptor func(*http.Request, Handler) (*http.Response, error)

Interceptor is a user defined function that can alter a request before it's sent and/or alter a response before it's returned to the caller