Go Micro

Go Micro is a framework for distributed systems development.

📖 Documentation | Sponsor the project

Overview

Go Micro provides the core requirements for distributed systems development including RPC and Event driven communication. The Go Micro philosophy is sane defaults with a pluggable architecture. We provide defaults to get you started quickly but everything can be easily swapped out.

Features

Go Micro abstracts away the details of distributed systems. Here are the main features.

• Authentication - Auth is built in as a first class citizen. Authentication and authorization enable secure zero trust networking by providing every service an identity and certificates. This additionally includes rule based access control.

• Dynamic Config - Load and hot reload dynamic config from anywhere. The config interface provides a way to load application level config from any source such as env vars, file, etcd. You can merge the sources and even define fallbacks.

• Data Storage - A simple data store interface to read, write and delete records. It includes support for many storage backends in the plugins repo. State and persistence becomes a core requirement beyond prototyping and Micro looks to build that into the framework.

• Service Discovery - Automatic service registration and name resolution. Service discovery is at the core of micro service development. When service A needs to speak to service B it needs the location of that service. The default discovery mechanism is multicast DNS (mdns), a zeroconf system.

• Load Balancing - Client side load balancing built on service discovery. Once we have the addresses of any number of instances of a service we now need a way to decide which node to route to. We use random hashed load balancing to provide even distribution across the services and retry a different node if there's a problem.

• Message Encoding - Dynamic message encoding based on content-type. The client and server will use codecs along with content-type to seamlessly encode and decode Go types for you. Any variety of messages could be encoded and sent from different clients. The client and server handle this by default. This includes protobuf and json by default.

• RPC Client/Server - RPC based request/response with support for bidirectional streaming. We provide an abstraction for synchronous communication. A request made to a service will be automatically resolved, load balanced, dialled and streamed.

• Async Messaging - PubSub is built in as a first class citizen for asynchronous communication and event driven architectures. Event notifications are a core pattern in micro service development. The default messaging system is a HTTP event message broker.

• Pluggable Interfaces - Go Micro makes use of Go interfaces for each distributed system abstraction. Because of this these interfaces are pluggable and allows Go Micro to be runtime agnostic. You can plugin any underlying technology.

Getting Started

To make use of Go Micro

go get go-micro.dev/v5@latest

Create a service and register a handler

package main

import (
        "go-micro.dev/v5"
)

type Request struct {
        Name string `json:"name"`
}

type Response struct {
        Message string `json:"message"`
}

type Say struct{}

func (h *Say) Hello(ctx context.Context, req *Request, rsp *Response) error {
        rsp.Message = "Hello " + req.Name
        return nil
}

func main() {
        // create the service
        service := micro.New("helloworld")

        // register handler
        service.Handle(new(Say))

        // run the service
        service.Run()
}

Set a fixed address

service := micro.NewService(
    micro.Name("helloworld"),
    micro.Address(":8080"),
)

Call it via curl

curl -XPOST \
     -H 'Content-Type: application/json' \
     -H 'Micro-Endpoint: Say.Hello' \
     -d '{"name": "alice"}' \
      http://localhost:8080

Experimental

There's a new genai package for generative AI capabilities.

Protobuf

Install the code generator and see usage in the docs:

go install go-micro.dev/v5/cmd/protoc-gen-micro@latest

Docs: internal/website/docs/getting-started.md

Command Line

Install the CLI:

go install go-micro.dev/v5/cmd/micro@latest

Quick Start

micro new helloworld   # Create a new service
cd helloworld
micro run              # Run with API gateway

Then open http://localhost:8080 to see your service and call it from the browser.

micro run

micro run starts your services with:

• API Gateway - HTTP to RPC proxy at /api/{service}/{method}
• Web Dashboard - Browse and call services at /
• Health Checks - Aggregated health at /health
• Hot Reload - Auto-rebuild on file changes

micro run                    # Gateway on :8080
micro run --address :3000    # Custom gateway port
micro run --no-gateway       # Services only
micro run --env production   # Use production environment

Configuration

For multi-service projects, create a micro.mu file:

service users
    path ./users
    port 8081

service posts
    path ./posts
    port 8082
    depends users

env development
    DATABASE_URL sqlite://./dev.db

The gateway runs on :8080 by default, so services should use other ports.

See cmd/micro/README.md for full CLI documentation.

Docs: internal/website/docs

Package reference: https://pkg.go.dev/go-micro.dev/v5

Selected topics:

• Getting Started: internal/website/docs/getting-started.md
• Plugins overview: internal/website/docs/plugins.md
• Learn by Example: internal/website/docs/examples/index.md

Adopters

• Sourse - Work in the field of earth observation, including embedded Kubernetes running onboard aircraft, and we’ve built a mission management SaaS platform using Go Micro.