Plugins

A repository for micro plugins

Overview

Micro tooling is built on a powerful pluggable architecture. Plugins can be swapped out with zero code changes. This repository contains plugins for all micro related tools. Read on for further info.

Check out the Micro on NATS blog post to learn more about plugins.

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Getting Started

• Contents
• Usage
• Build Pattern
• Contributions

Contents

Contents of this repository:

Directory	Description
Broker	PubSub messaging; NATS, NSQ, RabbitMQ, Kafka
Client	RPC Clients; gRPC, HTTP
Codec	Message Encoding; BSON, Mercury
Micro	Micro Toolkit Plugins
Registry	Service Discovery; Etcd, Gossip, NATS
Selector	Load balancing; Label, Cache, Static
Server	RPC Servers; gRPC, HTTP
Transport	Bidirectional Streaming; NATS, RabbitMQ
Wrappers	Middleware; Circuit Breakers, Rate Limiting, Tracing

Usage

Plugins can be added to go-micro in the following ways. By doing so they'll be available to set via command line args or environment variables.

Import Plugins

import (
	"github.com/micro/go-micro/cmd"
	_ "github.com/micro/go-plugins/broker/rabbitmq"
	_ "github.com/micro/go-plugins/registry/kubernetes"
	_ "github.com/micro/go-plugins/transport/nats"
)

func main() {
	// Parse CLI flags
	cmd.Init()
}

The same is achieved when calling service.Init

import (
	"github.com/micro/go-micro"
	_ "github.com/micro/go-plugins/broker/rabbitmq"
	_ "github.com/micro/go-plugins/registry/kubernetes"
	_ "github.com/micro/go-plugins/transport/nats"
)

func main() {
	service := micro.NewService(
		// Set service name
		micro.Name("my.service"),
	)

	// Parse CLI flags
	service.Init()
}

Use via CLI Flags

Activate via a command line flag

go run service.go --broker=rabbitmq --registry=kubernetes --transport=nats

Use Plugins Directly

CLI Flags provide a simple way to initialise plugins but you can do the same yourself.

import (
	"github.com/micro/go-micro"
	"github.com/micro/go-plugins/registry/kubernetes"
)

func main() {
	registry := kubernetes.NewRegistry() //a default to using env vars for master API

	service := micro.NewService(
		// Set service name
		micro.Name("my.service"),
		// Set service registry
		micro.Registry(registry),
	)
}

Build Pattern

An anti-pattern is modifying the main.go file to include plugins. Best practice recommendation is to include plugins in a separate file and rebuild with it included. This allows for automation of building plugins and clean separation of concerns.

Create file plugins.go

package main

import (
	_ "github.com/micro/go-plugins/broker/rabbitmq"
	_ "github.com/micro/go-plugins/registry/kubernetes"
	_ "github.com/micro/go-plugins/transport/nats"
)

Build with plugins.go

go build -o service main.go plugins.go

Run with plugins

MICRO_BROKER=rabbitmq \
MICRO_REGISTRY=kubernetes \
MICRO_TRANSPORT=nats \
service

Contributions

A few contributions by others

Feature	Description	Author
Registry/Kubernetes	Service discovery via the Kubernetes API	@nickjackson
Registry/Zookeeper	Service discovery using Zookeeper	@HeavyHorst