micro/web/README.md
2019-06-03 19:32:31 +01:00

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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

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"),
)