car

README

micro sidecar

The micro sidecar is a language agnostic proxy for building highly available and fault tolerant microservices.

It is similar to Netflix's sidecar Prana or Buoyant's RPC Proxy Linkerd.

Example usage in many languages can be found at examples/sidecar

API

- /[service]/[method]
- /broker
- /registry
- /rpc

Features

The sidecar has all the features of go-micro. Here are the most relevant.

• Service registration and discovery
• Broker PubSub via WebSockets
• Healthchecking of services
• RPC or HTTP handler
• Load balancing, retries, timeouts
• Stats UI

Getting Started

Install

go get github.com/micro/micro

Run

The micro sidecar runs on port 8081 by default.

Starting the sidecar

micro sidecar

Optionally specify app server name and address if you want to auto register an app on startup.

micro sidecar --server_name=foo --server_address=127.0.0.1:9090

Serve Secure TLS

The Sidecar supports serving securely with TLS certificates

micro --enable_tls --tls_cert_file=/path/to/cert --tls_key_file=/path/to/key sidecar

Auto Healthcheck

Start micro sidecar with "--healthcheck_url=" to enable the healthchecker

It does the following:

• Automatic service registration
• Periodic HTTP healthchecking
• Deregistration on non-200 response

micro sidecar --server_name=foo --server_address=127.0.0.1:9090 \
	--healthcheck_url=http://127.0.0.1:9090/health

Registry

Register Service

// specify ttl as a param to expire the registration
// units ns|us|ms|s|m|h
// http://127.0.0.1:8081/registry?ttl=10s

curl -H 'Content-Type: application/json' http://127.0.0.1:8081/registry -d 
{
	"Name": "foo.bar",
	"Nodes": [{
		"Port": 9091,
		"Address": "127.0.0.1",
		"Id": "foo.bar-017da09a-734f-11e5-8136-68a86d0d36b6"
	}]
}

Deregister Service

curl -X "DELETE" -H 'Content-Type: application/json' http://127.0.0.1:8081/registry -d 
{
	"Name": "foo.bar",
	"Nodes": [{
		"Port": 9091,
		"Address": "127.0.0.1",
		"Id": "foo.bar-017da09a-734f-11e5-8136-68a86d0d36b6"
	}]
}

Get Service

curl http://127.0.0.1:8081/registry?service=go.micro.srv.example
{
	"name":"go.micro.srv.example",
	"nodes":[{
		"id":"go.micro.srv.example-c5718d29-da2a-11e4-be11-68a86d0d36b6",
		"address":"[::]","port":60728
	}]
}

RPC Handler

Query micro services using json or protobuf. Requests to the backend will be made using the go-micro RPC client.

Using /[service]/[method]

Default namespace of services called are go.micro.srv

curl -H 'Content-Type: application/json' -d '{"name": "John"}' http://127.0.0.1:8081/example/call

Using /rpc endpoint

curl -d 'service=go.micro.srv.example' \
	-d 'method=Example.Call' \
	-d 'request={"name": "John"}' http://127.0.0.1:8081/rpc

Proxy Handler

Like the api and web servers, the sidecar can provide a full http proxy.

Enable proxy handler on the command line

micro sidecar --handler=proxy

The first element in the url path will be used along with the namespace as the service to route to.

RPC Request Mapping

URL Path mapping is the same as the micro API

Mapping of URLs are as follows:

Path	Service	Method
/foo/bar	go.micro.srv.foo	Foo.Bar
/foo/bar/baz	go.micro.srv.foo	Bar.Baz
/foo/bar/baz/cat	go.micro.srv.foo.bar	Baz.Cat

Versioned API URLs can easily be mapped to service names:

Path	Service	Method
/foo/bar	go.micro.srv.foo	Foo.Bar
/v1/foo/bar	go.micro.srv.v1.foo	Foo.Bar
/v1/foo/bar/baz	go.micro.srv.v1.foo	Bar.Baz
/v2/foo/bar	go.micro.srv.v2.foo	Foo.Bar
/v2/foo/bar/baz	go.micro.srv.v2.foo	Bar.Baz

Broker

Connect to the micro broker via websockets

c, _, _ := websocket.DefaultDialer.Dial("ws://127.0.0.1:8081/broker?topic=foo", make(http.Header))

// optionally specify "queue=[queue name]" param to distribute traffic amongst subscribers
// websocket.DefaultDialer.Dial("ws://127.0.0.1:8081/broker?topic=foo&queue=group-1", make(http.Header))

go func() {
	for {
		_, p, err := c.ReadMessage()
		if err != nil {
			return
		}
		var msg *broker.Message
		json.Unmarshal(p, &msg)
		fmt.Println(msg.Data)
	}
}()

ticker := time.NewTicker(time.Second)

for _ = range ticker.C {
	if err := c.WriteMessage(1, []byte(`hello world`)); err != nil {
		return
	}
}

CLI Proxy

The sidecar also acts as a proxy for the CLI to access remote environments

$ micro --proxy_address=127.0.0.1:8081 list services
go.micro.srv.greeter

Stats Dashboard

Enable a stats dashboard via the --enable_stats flag. It will be exposed on /stats.

micro --enable_stats sidecar

Documentation

Overview

Package car is a language agnostic rpc proxy

Index

• Variables
• func Commands() []cli.Command
• func Plugins() []plugin.Plugin
• func Register(pl plugin.Plugin) error

Variables

var (
	Name         = "go.micro.sidecar"
	Address      = ":8081"
	Handler      = "rpc"
	RootPath     = "/"
	ProxyPath    = "/{service:[a-zA-Z0-9]+}"
	BrokerPath   = "/broker"
	HealthPath   = "/health"
	RegistryPath = "/registry"
	RPCPath      = "/rpc"
	CORS         = map[string]bool{"*": true}
	Namespace    = "go.micro.srv"
)

Functions

func Commands

func Commands() []cli.Command

func Plugins

func Plugins() []plugin.Plugin

Plugins lists the sidecar plugins

func Register

func Register(pl plugin.Plugin) error

Register registers an sidecar plugin