micro

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 Go to latest Published: Oct 3, 2022 License: Apache-2.0 Imports: 24 Imported by: 9

README

Go Micro v5 License Go.Dev reference Go Report Card Discord

Go Micro is a framework for distributed systems development.

Have a look at examples for examples.

v5 is a proof of concept - DO NOT USE

v5 intodruces wire generated code.

See this Diagram for an overview:

microwire diagram

Goals
  • Add backward incompatible lint fixes
  • Remove all globals
  • Backward compatiblity is not required at all places but a nice to have
  • Replace util/cmd
  • Choose what features you want from go-micro:
    • You can select if you want Auth/Events/"name it here"
    • If you don't want CLI opts you can exclude them
    • No default plugins, that makes the core even slimer
  • Choose your Prefix for CLI opts not only "micro"
  • No more Globals, everything lives in the DI
  • wire for the end users will allow them wire theier app together
  • Easy to make a micro Service and a monolith with the same codebase
Implemented features
  • util/cmd/ is gone
  • web/ is gone
  • config/source/(env|file) is gone
  • 6 components, component generator so easy to add them all
  • Cli is a component now, its easy to replace it with other flag+env plugins
  • ArgPrefix("myapp") for micro flags and environment vars
  • NoFlags() option, this will disable all micro flags
  • Config() option, to provide a config file
  • Each component reads the configuration by its own, config is tightly coupled
Example yaml config
---
Broker:
  Enabled: true
  Plugin: nats
  Addresses:
    - nats://localhost:4222
Registry:
  Enabled: true
  Plugin: nats
  Addresses:
    - nats://localhost:4222
Store:
  Enabled: false
Transport:
  Enabled: true
  Plugin: nats
  Addresses:
    - nats://localhost:4222

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 memory, file and CockroachDB by default. 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.

  • 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.

  • 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.

  • 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

package main

import (
    _ "github.com/go-micro/microwire-plugins/sets/defaults/v5"
    micro "github.com/go-micro/microwire/v5"
    "github.com/go-micro/microwire/v5/logger"
)

func main() {
    service, err := micro.NewService(
        micro.Name("livecyclehooks"),
        micro.Usage("A POC for go-micro.dev/v5"),
        micro.Version("v0.0.1"),
        micro.ArgPrefix(""),
    )
    if err != nil {
        logger.Fatal(err)
    }

    if err := service.Run(); err != nil {
        logger.Fatal(err)
    }
}

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

Constants

This section is empty.

Variables

View Source 
var DiCliSet = wire.NewSet(
	cli.ProvideCli,
	cli.ProvideParsed,
	cli.ProvideConfig,
)
View Source 
var DiNoCliSet = wire.NewSet(
	configdi.ProvideConfigor,
	auth.DiNoCliSet,
	broker.DiNoCliSet,
	cache.DiNoCliSet,
	registry.DiNoCliSet,
	store.DiNoCliSet,
	transport.DiNoCliSet,
)
View Source 
var DiNoDiSet = wire.NewSet(
	ProvideFlags,
	ProvideAllService,
)
View Source 
var DiSet = wire.NewSet(
	configdi.ProvideConfigor,
	auth.DiSet,
	broker.DiSet,
	cache.DiSet,
	registry.DiSet,
	store.DiSet,
	transport.DiSet,
)

DiSet is a set of all things components need, except the components themself.

Functions

func NewContext 

func NewContext(ctx context.Context, s Service) context.Context

NewContext returns a new Context with the Service embedded within it.

func ProvideConfigFile added in v5.0.1 

func ProvideConfigFile(
	options *Options,
) (di.DiConfig, error)

func ProvideFlags added in v5.0.1 

func ProvideFlags(
	_ *auth.DiFlags,
	_ *broker.DiFlags,
	_ *cache.DiFlags,
	_ *registry.DiFlags,
	_ *store.DiFlags,
	_ *transport.DiFlags,
) (di.DiFlags, error)

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 CliArgs added in v5.0.1 

type CliArgs []string

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.

func NewEvent 

func NewEvent(topic string, c client.Client) Event

NewEvent creates a new event publisher.

type HookFunc 

type HookFunc func(Service) error

type Option 

type Option func(*Options)

func Action added in v5.0.1 

func Action(fn HookFunc) Option

Action is an alias for AfterStart.

func AddListenOption 

func AddListenOption(option server.Option) Option

Add opt to server option.

func Address 

func Address(addr string) Option

Address sets the address of the server.

func AfterStart 

func AfterStart(fn HookFunc) Option

AfterStart run funcs after service starts.

func AfterStop 

func AfterStop(fn HookFunc) Option

AfterStop run funcs after service stops.

func ArgPrefix added in v5.0.1 

func ArgPrefix(n string) Option

ArgPrefix is the cli prefix for args.

func Auth 

func Auth(a auth.Auth) Option

Auth sets the auth for the service.

func BeforeStart 

func BeforeStart(fn HookFunc) Option

BeforeStart run funcs before service starts.

func BeforeStop 

func BeforeStop(fn HookFunc) Option

BeforeStop run funcs before service stops.

func Broker 

func Broker(b broker.Broker) Option

Broker to be used for service.

func Cache 

func Cache(c cache.Cache) Option

func Client 

func Client(c client.Client) Option

Client to be used for service.

func Config 

func Config(c config.Config) Option

Config sets the config for the service.

func ConfigFile added in v5.0.1 

func ConfigFile(n string) Option

ConfigFile is the config file to read in.

func Context 

func Context(ctx context.Context) Option

Context specifies a context for the service. Can be used to signal shutdown of the service and for extra option values.

func Description added in v5.0.1 

func Description(n string) Option

Description is the Description in cli usage.

func Flags added in v5.0.1 

func Flags(n []mCli.Flag) Option

Flags is a list of additional flags to add you can parse them in Hooks.

func HandleSignal 

func HandleSignal(b bool) Option

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 Logger 

func Logger(l logger.Logger) Option

Logger sets the logger for the service.

func Metadata 

func Metadata(md map[string]string) Option

Metadata associated with the service.

func Name 

func Name(n string) Option

Name of the service.

func NoFlags added in v5.0.1 

func NoFlags() Option

NoFlags is a marker that no micro flags should be there.

func Profile 

func Profile(p profile.Profile) Option

Profile to be used for debug profile.

func RegisterInterval 

func RegisterInterval(t time.Duration) Option

RegisterInterval specifies the interval on which to re-register.

func RegisterTTL 

func RegisterTTL(t time.Duration) Option

RegisterTTL specifies the TTL to use when registering the service.

func Registry 

func Registry(r registry.Registry) Option

Registry sets the registry for the service and the underlying components.

func Runtime 

func Runtime(r runtime.Runtime) Option

Runtime sets the runtime.

func Selector 

func Selector(s selector.Selector) Option

Selector sets the selector for the service client.

func Server 

func Server(s server.Server) Option

Server to be used for service.

func Store 

func Store(s store.Store) Option

Store sets the store to use.

func Tracer 

func Tracer(t trace.Tracer) Option

Tracer sets the tracer for the service.

func Transport 

func Transport(t transport.Transport) Option

Transport sets the transport for the service and the underlying components.

func Usage added in v5.0.1 

func Usage(n string) Option

Usage is the Usage in cli.

func Version 

func Version(v string) Option

Version of the service.

func WrapCall 

func WrapCall(w ...client.CallWrapper) Option

WrapCall is a convenience method for wrapping a Client CallFunc.

func WrapClient 

func WrapClient(w ...client.Wrapper) Option

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 {
	ArgPrefix   string
	Name        string
	Description string
	Version     string
	Usage       string
	NoFlags     bool
	ConfigFile  string
	Flags       []mCli.Flag

	// TODO: Remove me
	Auth      auth.Auth
	Broker    broker.Broker
	Cache     cache.Cache
	Config    config.Config
	Client    client.Client
	Server    server.Server
	Store     store.Store
	Registry  registry.Registry
	Runtime   runtime.Runtime
	Transport transport.Transport
	Profile   profile.Profile
	Logger    logger.Logger

	// Before and After funcs
	Actions     []HookFunc
	BeforeStart []HookFunc
	BeforeStop  []HookFunc
	AfterStart  []HookFunc
	AfterStop   []HookFunc

	// Other options for implementations of the interface
	// can be stored in a context
	Context context.Context

	Signal bool
}

Options for micro service.

func NewOptions added in v5.0.1 

func NewOptions(opts ...Option) *Options

type Publisher 

type Publisher = Event

Type alias to satisfy the deprecation.

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 

func FromContext(ctx context.Context) (Service, bool)

FromContext retrieves a Service from the Context.

func NewMicroService added in v5.0.1 

func NewMicroService(opts ...Option) Service

NewMicroService creates and returns a new Service based on the packages within.

func NewService 

func NewService(opts ...Option) (Service, error)

func ProvideAllService added in v5.0.1 

func ProvideAllService(
	opts *Options,
	auth auth.Auth,
	broker broker.Broker,
	cache cache.Cache,
	registry registry.Registry,
	store store.Store,
	transport transport.Transport,
) (Service, error)

Source Files

View all Source files

Directories

Path Synopsis
api
Package api is for building api gateways
 Package api is for building api gateways
Package auth provides authentication and authorization capability
 Package auth provides authentication and authorization capability
Package broker is an interface used for asynchronous messaging
 Package broker is an interface used for asynchronous messaging
Package client is an interface for an RPC client
 Package client is an interface for an RPC client
Package codec is an interface for encoding messages
 Package codec is an interface for encoding messages
Package config is an interface for dynamic configuration.
 Package config is an interface for dynamic configuration.
debug
Package errors provides a way to return detailed information for an RPC request error.
 Package errors provides a way to return detailed information for an RPC request error.
Package events is for event streaming and storage
 Package events is for event streaming and storage
Package log provides a log interface
 Package log provides a log interface
Package metadata is a way of defining message headers
 Package metadata is a way of defining message headers
Package mdns is a multicast dns registry
 Package mdns is a multicast dns registry
Package runtime is a service runtime manager
 Package runtime is a service runtime manager
Package selector is a way to pick a list of service nodes
 Package selector is a way to pick a list of service nodes
Package server is an interface for a micro server
 Package server is an interface for a micro server
Package store is an interface for distributed data storage.
 Package store is an interface for distributed data storage.
Package sync is an interface for distributed synchronization
 Package sync is an interface for distributed synchronization
Package transport is an interface for synchronous connection based communication
 Package transport is an interface for synchronous connection based communication
util

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