moleculer

README

Moleculer Go

🚀 Progressive microservices framework for Go

Inspired and compatible with Moleculer JS

Simple, fast, light and fun to develop with. Also easy, very easy to test ;)

Get Started

• http://gomicro.services (Official site and Documentation)
• Database examples
• WhatsApp App
• Benchmark

Example

package main

import (
	"fmt"

	"github.com/moleculer-go/moleculer"
	"github.com/moleculer-go/moleculer/broker"
)

type MathService struct {
}

func (s MathService) Name() string {
	return "math"
}

func (s *MathService) Add(params moleculer.Payload) int {
	return params.Get("a").Int() + params.Get("b").Int()
}

func (s *MathService) Sub(a int, b int) int {
	return a - b
}

func main() {
	var bkr = broker.New(&moleculer.Config{LogLevel: "error"})
	bkr.Publish(&MathService{})
	bkr.Start()
	result := <-bkr.Call("math.add", map[string]int{
		"a": 10,
		"b": 130,
	})
	fmt.Println("result: ", result.Int())
	//$ result: 140
	bkr.Stop()
}

Roadmap

v0.1.0 (MVP)

Development is complete - Documentation is in-progress and benchmark is also in-progress.

Contents:

• Service Broker
• Transit and Transport
• Actions (request-reply)
• Events
• Mixins
• Load balancing for actions and events (random round-robin)
• Service registry & dynamic service discovery
• Versioned services
• Middlewares
• NATS Streaming Transporter
• JSON Serializer
• Examples :)

v0.2.0 (Beta RC1)

• Action validators
• Support for streams
• More Load balancing implementations (cpu-usage, latency)
• Fault tolerance features (Circuit Breaker, Bulkhead, Retry, Timeout, Fallback)
• Built-in caching solution (memory, Redis)
• More transporters (gRPC, TCP, Redis, Kafka)
• More serializers (Avro, MsgPack, Protocol Buffer, Thrift)

v0.3.0 (Beta)

• Performance and Optimization
• More DB Adaptors (SQLLite, Firebase, MySQL)
• CLI for Project Seed Generation

v0.4.0 (Alpha)

• Event Sourcing Mixins

v0.5.0 (Release)

Installation

$ go get github.com/moleculer-go/moleculer

Running examples

# simple moleculer db example with memory adaptor
$ go run github.com/moleculer-go/store/examples/users

# simple moleculer db example with Mongo adaptor
$ go run github.com/moleculer-go/store/examples/usersMongo

# simple moleculer db example with SQLite adaptor
$ go run github.com/moleculer-go/store/examples/usersSQLite

# complex moleculer db example with population of fields by other services
$ go run github.com/moleculer-go/store/examples/populates

Documentation

Index

• Variables
• type Action
• type ActionDelegateFunc
• type ActionHandler
• type ActionSchema
• type BrokerContext
• type BrokerContextFunc
• type BrokerDelegates
• type BusFunc
• type Config
• type Context
• type CreatedFunc
• type EmitEventFunc
• type Event
• type EventHandler
• type ForEachFunc
• type LifecycleFunc
• type LocalNodeFunc
• type LoggerFunc
• type Middleware
• type MiddlewareHandler
• type MiddlewareHandlerFunc
• type Middlewares
• type Mixin
• type MultActionDelegateFunc
• type Node
• type ObjectSchema
• type Options
• type Payload
• type PublishFunc
• type RetryPolicy
• type ServiceForActionFunc
• type ServiceSchema
• type TransporterFactoryFunc
• type WaitForFunc

Variables

var DefaultConfig = Config{
	LogLevel:                   "INFO",
	LogFormat:                  "TEXT",
	DiscoverNodeID:             discoverNodeID,
	Transporter:                "MEMORY",
	HeartbeatFrequency:         5 * time.Second,
	HeartbeatTimeout:           15 * time.Second,
	OfflineCheckFrequency:      20 * time.Second,
	OfflineTimeout:             10 * time.Minute,
	DontWaitForNeighbours:      true,
	NeighboursCheckTimeout:     2 * time.Second,
	WaitForDependenciesTimeout: 2 * time.Second,
	Metrics:                    false,
	MetricsRate:                1,
	DisableInternalServices:    false,
	DisableInternalMiddlewares: false,
	Created:                    func() {},
	Started:                    func() {},
	Stopped:                    func() {},
	MaxCallLevel:               100,
	RetryPolicy: RetryPolicy{
		Enabled: false,
	},
	RequestTimeout:            1 * time.Minute,
	MCallTimeout:              5 * time.Second,
	WaitForNeighboursInterval: 200 * time.Millisecond,
}

Types

type Action

type Action struct {
	Name        string
	Handler     ActionHandler
	Schema      ActionSchema
	Settings    map[string]interface{}
	Description string
}

type ActionDelegateFunc

type ActionDelegateFunc func(context BrokerContext, opts ...Options) chan Payload

type ActionHandler

type ActionHandler func(context Context, params Payload) interface{}

type ActionSchema

type ActionSchema interface {
}

ActionSchema is used by the validation engine to check if parameters sent to the action are valid.

type BrokerContext

type BrokerContext interface {
	Call(actionName string, params interface{}, opts ...Options) chan Payload
	Emit(eventName string, params interface{}, groups ...string)

	ChildActionContext(actionName string, params Payload, opts ...Options) BrokerContext
	ChildEventContext(eventName string, params Payload, groups []string, broadcast bool) BrokerContext

	ActionName() string
	EventName() string
	Payload() Payload
	Groups() []string
	IsBroadcast() bool

	//export context info in a map[string]
	AsMap() map[string]interface{}

	SetTargetNodeID(targetNodeID string)
	TargetNodeID() string

	ID() string
	RequestID() string
	Meta() Payload
	UpdateMeta(Payload)
	Logger() *log.Entry

	Publish(...interface{})
	WaitFor(services ...string) error
}

type BrokerContextFunc

type BrokerContextFunc func() BrokerContext

type BrokerDelegates

type BrokerDelegates struct {
	LocalNode          LocalNodeFunc
	Logger             LoggerFunc
	Bus                BusFunc
	IsStarted          isStartedFunc
	Config             Config
	MultActionDelegate MultActionDelegateFunc
	ActionDelegate     ActionDelegateFunc
	EmitEvent          EmitEventFunc
	BroadcastEvent     EmitEventFunc
	HandleRemoteEvent  EmitEventFunc
	ServiceForAction   ServiceForActionFunc
	BrokerContext      BrokerContextFunc
	MiddlewareHandler  MiddlewareHandlerFunc
	Publish            PublishFunc
	WaitFor            WaitForFunc
}

Needs Refactoring..2 broker interfaces.. one for regiwstry.. and for for all others.

type BusFunc

type BusFunc func() *bus.Emitter

type Config

type Config struct {
	LogLevel                   string
	LogFormat                  string
	DiscoverNodeID             func() string
	Transporter                string
	TransporterFactory         TransporterFactoryFunc
	HeartbeatFrequency         time.Duration
	HeartbeatTimeout           time.Duration
	OfflineCheckFrequency      time.Duration
	OfflineTimeout             time.Duration
	NeighboursCheckTimeout     time.Duration
	WaitForDependenciesTimeout time.Duration
	Middlewares                []Middlewares
	Namespace                  string
	RequestTimeout             time.Duration
	MCallTimeout               time.Duration
	RetryPolicy                RetryPolicy
	MaxCallLevel               int
	Metrics                    bool
	MetricsRate                float32
	DisableInternalServices    bool
	DisableInternalMiddlewares bool
	DontWaitForNeighbours      bool
	WaitForNeighboursInterval  time.Duration
	Created                    func()
	Started                    func()
	Stopped                    func()

	Services map[string]interface{}
}

type Context

type Context interface {
	//context methods used by services
	MCall(map[string]map[string]interface{}) chan map[string]Payload
	Call(actionName string, params interface{}, opts ...Options) chan Payload
	Emit(eventName string, params interface{}, groups ...string)
	Broadcast(eventName string, params interface{}, groups ...string)
	Logger() *log.Entry

	Payload() Payload
	Meta() Payload
}

type CreatedFunc

type CreatedFunc func(ServiceSchema, *log.Entry)

type EmitEventFunc

type EmitEventFunc func(context BrokerContext)

type Event

type Event struct {
	Name    string
	Group   string
	Handler EventHandler
}

type EventHandler

type EventHandler func(context Context, params Payload)

type ForEachFunc

type ForEachFunc func(iterator func(key interface{}, value Payload) bool)

type LifecycleFunc

type LifecycleFunc func(BrokerContext, ServiceSchema)

type LocalNodeFunc

type LocalNodeFunc func() Node

type LoggerFunc

type LoggerFunc func(name string, value string) *log.Entry

type Middleware

type Middleware interface {
	CallHandlers(name string, params interface{}) interface{}
}

type MiddlewareHandler

type MiddlewareHandler func(params interface{}, next func(...interface{}))

type MiddlewareHandlerFunc

type MiddlewareHandlerFunc func(name string, params interface{}) interface{}

type Middlewares

type Middlewares map[string]MiddlewareHandler

type Mixin

type Mixin struct {
	Name         string
	Dependencies []string
	Settings     map[string]interface{}
	Metadata     map[string]interface{}
	Hooks        map[string]interface{}
	Actions      []Action
	Events       []Event
	Created      CreatedFunc
	Started      LifecycleFunc
	Stopped      LifecycleFunc
}

type MultActionDelegateFunc

type MultActionDelegateFunc func(callMaps map[string]map[string]interface{}) chan map[string]Payload

type Node

type Node interface {
	GetID() string
	ExportAsMap() map[string]interface{}
	IsAvailable() bool
	Available()
	Unavailable()
	IsExpired(timeout time.Duration) bool
	Update(id string, info map[string]interface{}) bool

	IncreaseSequence()
	HeartBeat(heartbeat map[string]interface{})
	Publish(service map[string]interface{})
}

type ObjectSchema

type ObjectSchema struct {
	Source interface{}
}

type Options

type Options struct {
	Meta   Payload
	NodeID string
}

type Payload

type Payload interface {
	First() Payload
	Sort(field string) Payload
	Remove(fields ...string) Payload
	AddItem(value interface{}) Payload
	Add(field string, value interface{}) Payload
	AddMany(map[string]interface{}) Payload
	MapArray() []map[string]interface{}
	RawMap() map[string]interface{}
	Bson() bson.M
	BsonArray() bson.A
	Map() map[string]Payload
	Exists() bool
	IsError() bool
	Error() error
	Value() interface{}
	ValueArray() []interface{}
	Int() int
	IntArray() []int
	Int64() int64
	Int64Array() []int64
	Uint() uint64
	UintArray() []uint64
	Float32() float32
	Float32Array() []float32
	Float() float64
	FloatArray() []float64
	String() string
	StringArray() []string
	Bool() bool
	BoolArray() []bool
	ByteArray() []byte
	Time() time.Time
	TimeArray() []time.Time
	Array() []Payload
	Len() int
	Get(path string) Payload
	//Only return a payload containing only the field specified
	Only(path string) Payload
	IsArray() bool
	IsMap() bool
	ForEach(iterator func(key interface{}, value Payload) bool)
}

Payload contains the data sent/return to actions. I has convinience methods to read action parameters by name with the right type.

type PublishFunc

type PublishFunc func(...interface{})

type RetryPolicy

type RetryPolicy struct {
	Enabled  bool
	Retries  int
	Delay    int
	MaxDelay int
	Factor   int
	Check    func(error) bool
}

type ServiceForActionFunc

type ServiceForActionFunc func(string) []*ServiceSchema

type ServiceSchema

type ServiceSchema struct {
	Name         string
	Version      string
	Dependencies []string
	Settings     map[string]interface{}
	Metadata     map[string]interface{}
	Hooks        map[string]interface{}
	Mixins       []Mixin
	Actions      []Action
	Events       []Event
	Created      CreatedFunc
	Started      LifecycleFunc
	Stopped      LifecycleFunc
}

type TransporterFactoryFunc

type TransporterFactoryFunc func() interface{}

type WaitForFunc

type WaitForFunc func(...string) error