go-micro/web

Go Web

Go Web is a framework for micro service web development.

Overview

Go Web provides a tiny HTTP web server library which leverages go-micro to create micro web services as first class citizens in a microservice world. It wraps go-micro to give you service discovery, heartbeating and the ability to create web apps as microservices.

Features

• Service Discovery - Services are automatically registered in service discovery on startup. Go Web includes a http.Client with pre-initialised roundtripper which makes use of service discovery so you can use service names.

• Heartbeating - Go Web apps will periodically heartbeat with service discovery to provide liveness updates. In the event a service fails it will be removed from the registry after a pre-defined expiry time.

• Custom Handlers - Specify your own http router for handling requests. This allows you to maintain full control over how you want to route to internal handlers.

• Static Serving - Go Web automatically detects a local static html dir and serves files if no route handler is specified. A quick solution for those who want to write JS web apps as microservices.

Getting Started

• Dependencies
• Usage
• Set Handler
• Call Service
• Static Files

Dependencies

Go Web makes use of Go Micro which means it needs service discovery

See the go-micro for install instructions

For a quick start use consul

# install
brew install consul

# run
consul agent -dev

Usage

service := web.NewService(
	web.Name("example.com"),
)

service.HandleFunc("/foo", fooHandler)

if err := service.Init(); err != nil {
	log.Fatal(err)
}

if err := service.Run(); err != nil {
	log.Fatal(err)
}

Set Handler

You might have a preference for a HTTP handler, so use something else. This loses the ability to register endpoints in discovery but we'll fix that soon.

import "github.com/gorilla/mux"

r := mux.NewRouter()
r.HandleFunc("/", indexHandler)
r.HandleFunc("/objects/{object}", objectHandler)

service := web.NewService(
	web.Handler(r)
)

Call Service

Go-web includes a http.Client with a custom http.RoundTripper that uses service discovery

c := service.Client()

rsp, err := c.Get("http://example.com/foo")

This will lookup service discovery for the service example.com and route to one of the available nodes.

Static Files

Go web was always meant as a way to register web apps where the majority of the code would be written in JS. To enable that by default, if no handler is registered on "/" and we find a local "html" directory then static files will be served.

You will see a log output like so.

2019/05/12 14:55:47 Enabling static file serving from /tmp/foo/html

If you want to set this path manually use the StaticDir option. If a relative path is specified we will use os.Getwd() and prefix this.

service := web.NewService(
	web.Name("example.com"),
	web.StaticDir("/tmp/example.com/html"),
)