README
¶
Go Micro 
Go Micro is a framework for distributed systems development.
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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.
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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.
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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.
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Data Storage - A simple data store interface to read, write and delete records. It includes support for memory, file and CockroachDB by default. State and persistence becomes a core requirement beyond prototyping and Micro looks to build that into the framework.
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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.
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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.
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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.
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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.
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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.
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Event Streaming - PubSub is great for async notifications but for more advanced use cases event streaming is preferred. Offering persistent storage, consuming from offsets and acking. Go Micro includes support for NATS Jetstream and Redis streams.
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Synchronization - Distributed systems are often built in an eventually consistent manner. Support for distributed locking and leadership are built in as a Sync interface. When using an eventually consistent database or scheduling use the Sync interface.
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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 import it
import "go-micro.dev/v4
Define a handler (protobuf is optionally supported - see example)
type Request struct {
Name string `json:"name"`
}
type Response struct {
Message string `json:"message"`
}
type Helloworld struct{}
func (h *Helloworld) Greeting(ctx context.Context, req *Request, rsp *Response) error {
rsp.Message = "Hello " + req.Name
return nil
}
Create, initialise and run the service
// create a new service
service := micro.NewService(
micro.Name("helloworld"),
micro.Handle(new(Helloworld)),
)
// initialise flags
service.Init()
// start the service
service.Run()
Optionally set fixed address
service := micro.NewService(
// set address
micro.Handle(":8080"),
)
Call it via curl
curl -XPOST \
-H 'Content-Type: application/json' \
-H 'Micro-Endpoint: Helloworld.Greeting' \
-d '{"name": "alice"}' \
http://localhost:8080
See the examples for detailed information on usage.
Toolkit
See github.com/go-micro for tooling.
Changelog
See CHANGELOG.md for release history.
License
Go Micro is Apache 2.0 licensed.
Documentation
¶
Overview ¶
Package micro is a pluggable framework for microservices
Index ¶
- func NewContext(ctx context.Context, s Service) context.Context
- func RegisterHandler(s server.Server, h interface{}, opts ...server.HandlerOption) error
- func RegisterSubscriber(topic string, s server.Server, h interface{}, opts ...server.SubscriberOption) error
- type Event
- type Option
- func Action(a func(*cli.Context) error) Option
- func AddListenOption(option server.Option) Option
- func Address(addr string) Option
- func AfterStart(fn func() error) Option
- func AfterStop(fn func() error) Option
- func Auth(a auth.Auth) Option
- func BeforeStart(fn func() error) Option
- func BeforeStop(fn func() error) Option
- func Broker(b broker.Broker) Option
- func Cache(c cache.Cache) Option
- func Client(c client.Client) Option
- func Cmd(c cmd.Cmd) Option
- func Config(c config.Config) Option
- func Context(ctx context.Context) Option
- func Flags(flags ...cli.Flag) Option
- func Handle(v interface{}) Option
- func HandleSignal(b bool) Option
- func Logger(l logger.Logger) Option
- func Metadata(md map[string]string) Option
- func Name(n string) Option
- func Profile(p profile.Profile) Option
- func RegisterInterval(t time.Duration) Option
- func RegisterTTL(t time.Duration) Option
- func Registry(r registry.Registry) Option
- func Runtime(r runtime.Runtime) Option
- func Selector(s selector.Selector) Option
- func Server(s server.Server) Option
- func Store(s store.Store) Option
- func Tracer(t trace.Tracer) Option
- func Transport(t transport.Transport) Option
- func Version(v string) Option
- func WrapCall(w ...client.CallWrapper) Option
- func WrapClient(w ...client.Wrapper) Option
- func WrapHandler(w ...server.HandlerWrapper) Option
- func WrapSubscriber(w ...server.SubscriberWrapper) Option
- type Options
- type Publisher
- type Service
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func NewContext ¶
NewContext returns a new Context with the Service embedded within it.
func RegisterHandler ¶
func RegisterHandler(s server.Server, h interface{}, opts ...server.HandlerOption) error
RegisterHandler is syntactic sugar for registering a handler.
func RegisterSubscriber ¶
func RegisterSubscriber(topic string, s server.Server, h interface{}, opts ...server.SubscriberOption) error
RegisterSubscriber is syntactic sugar for registering a subscriber.
Types ¶
type Event ¶
type Event interface {
// Publish publishes a message to the event topic
Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error
}
Event is used to publish messages to a topic.
type Option ¶
type Option func(*Options)
func AddListenOption ¶ added in v4.8.1
Add opt to server option.
func AfterStart ¶
AfterStart run funcs after service starts.
func BeforeStart ¶
BeforeStart run funcs before service starts.
func BeforeStop ¶
BeforeStop run funcs before service stops.
func Context ¶
Context specifies a context for the service. Can be used to signal shutdown of the service and for extra option values.
func Handle ¶ added in v4.10.1
func Handle(v interface{}) Option
Handle will register a handler without any fuss
func HandleSignal ¶
HandleSignal toggles automatic installation of the signal handler that traps TERM, INT, and QUIT. Users of this feature to disable the signal handler, should control liveness of the service through the context.
func RegisterInterval ¶
RegisterInterval specifies the interval on which to re-register.
func RegisterTTL ¶
RegisterTTL specifies the TTL to use when registering the service.
func WrapCall ¶
func WrapCall(w ...client.CallWrapper) Option
WrapCall is a convenience method for wrapping a Client CallFunc.
func WrapClient ¶
WrapClient is a convenience method for wrapping a Client with some middleware component. A list of wrappers can be provided. Wrappers are applied in reverse order so the last is executed first.
func WrapHandler ¶
func WrapHandler(w ...server.HandlerWrapper) Option
WrapHandler adds a handler Wrapper to a list of options passed into the server.
func WrapSubscriber ¶
func WrapSubscriber(w ...server.SubscriberWrapper) Option
WrapSubscriber adds a subscriber Wrapper to a list of options passed into the server.
type Options ¶
type Options struct {
Registry registry.Registry
Store store.Store
Auth auth.Auth
Cmd cmd.Cmd
Config config.Config
Client client.Client
Server server.Server
// Other options for implementations of the interface
// can be stored in a context
Context context.Context
Cache cache.Cache
Runtime runtime.Runtime
Profile profile.Profile
Transport transport.Transport
Logger logger.Logger
Broker broker.Broker
// Before and After funcs
BeforeStart []func() error
AfterStart []func() error
AfterStop []func() error
BeforeStop []func() error
Signal bool
}
Options for micro service.
type Service ¶
type Service interface {
// The service name
Name() string
// Init initializes options
Init(...Option)
// Options returns the current options
Options() Options
// Client is used to call services
Client() client.Client
// Server is for handling requests and events
Server() server.Server
// Run the service
Run() error
// The service implementation
String() string
}
Service is an interface that wraps the lower level libraries within go-micro. Its a convenience method for building and initializing services.
func FromContext ¶
FromContext retrieves a Service from the Context.
func NewService ¶
NewService creates and returns a new Service based on the packages within.
Source Files
Directories