servicehub

servicehub

The servicehub.Hub is Service Manager, which manages the startup, initialization, dependency, and shutdown of services.

Provider provide one or more services, and implement the servicehub.Provider interface to provide services.

The servicehub.Hub manages all providers registered by function servicehub.RegisterProvider .

Example

The configuration file examples.yaml

hello-provider:
    message: "hello world"

The code file main.go

package main

import (
	"context"
	"os"
	"time"

	"github.com/ping-cloudnative/moonlight-utils/base/logs"
	"github.com/ping-cloudnative/moonlight-utils/base/servicehub"
)

type config struct {
	Message string `file:"message" flag:"msg" default:"hi" desc:"message to show" env:"HELLO_MESSAGE"`
}

type provider struct {
	Cfg *config
	Log logs.Logger
}

func (p *provider) Init(ctx servicehub.Context) error {
	p.Log.Info("message: ", p.Cfg.Message)
	return nil
}

func (p *provider) Run(ctx context.Context) error {
	p.Log.Info("hello provider is running...")
	tick := time.NewTicker(3 * time.Second)
	defer tick.Stop()
	for {
		select {
		case <-tick.C:
			p.Log.Info("do something...")
		case <-ctx.Done():
			return nil
		}
	}
}

func init() {
	servicehub.Register("hello-provider", &servicehub.Spec{
		Services:    []string{"hello"},
		Description: "hello for example",
		ConfigFunc:  func() interface{} { return &config{} },
		Creator: func() servicehub.Provider {
			return &provider{}
		},
	})
}

func main() {
	hub := servicehub.New()
	hub.Run("examples", "", os.Args...)
}

Output:

➜ go run main.go
INFO[2021-03-23 11:55:34.830] message: hello world                          module=hello-provider
INFO[2021-03-23 11:55:34.830] provider hello-provider initialized          
INFO[2021-03-23 11:55:34.830] signals to quit:[hangup interrupt terminated quit] 
INFO[2021-03-23 11:55:34.831] hello provider is running...                  module=hello-provider
INFO[2021-03-23 11:55:37.831] do something...                               module=hello-provider
INFO[2021-03-23 11:55:40.835] do something...                               module=hello-provider
^C
INFO[2021-03-23 11:55:41.624] provider hello-provider Run exit  

Example details

More Examples

Reading Config

Support the following ways to read config, the priority from low to high is:

• default Tag In Struct
• System Environment Variable
• .env File Environment Variable
• Config File
• Flag

Supports file formats:

• yaml、yml
• json
• hcl
• toml
• ...