Go Micro provides the core requirements for distributed systems development including RPC and Event driven communication. The micro philosophy is sane defaults with a pluggable architecture. We provide defaults to get you started quickly but everything can be easily swapped out.
Go Micro abstracts away the details of distributed systems. Here are the main features.
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.
Request/Response - 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. The default transport is gRPC.
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 an embedded NATS server.
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. Find plugins in github.com/micro/go-plugins.
Go Micro makes use of protobuf by default. This is so we can code generate boilerplate code and also provide an efficient wire format for transferring data back and forth between services.
We also require some form of service discovery to resolve service names to their addresses along with metadata and endpoint information. See below for more info.
You’ll need to install protobuf to code generate API interfaces:
Service discovery is used to resolve service names to addresses. By default we provide a zeroconf discovery system using multicast DNS. This comes built-in on most operating systems. If you need something more resilient and multi-host then use etcd.
Etcd can be used as an alternative service discovery system.
- Download and run etcd
--registry=etcdto any command or the enviroment variable
MICRO_REGISTRY=etcd go run main.go
Discovery is pluggable. Find plugins for consul, kubernetes, zookeeper and more in the micro/go-plugins repo.
Go Micro is a framework for Go based development. You can easily get this with the go toolchain.
Import go-micro in your service
We provide release tags and would recommend to stick with the latest stable releases. Making use of go modules will enable this.
# enable go modules export GO111MODULE=on # initialise go modules in your app go mod init # now go get go get ./...
Writing a service
Go checkout the hello world example to get started