Menggunakan go-zero untuk melaksanakan pusat konfigurasi teragih

go get -u github.com/tal-tech/go-zero

CREATE TABLE `config` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `app_name` varchar(255) DEFAULT '',
    `key_name` varchar(255) DEFAULT '',
    `value` varchar(1024) DEFAULT '',
    `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `update_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

goctl api new -api config -dir config/api

type Config interface {
    GetConfig(ctx context.Context, req *model.GetConfigReq) (*model.GetConfigResp, error)
    WatchConfig(ctx context.Context, req *model.GetConfigReq) (*model.GetConfigResp, error)
}

[etcd]
  null=127.0.0.1:2379

func RefreshConfig() {
    etcdCli, err := clientv3.New(clientv3.Config{
        Endpoints:   *conf.Etcd,
        DialTimeout: time.Second * 3,
    })
    if err != nil {
        logx.Errorf("err: %v", err)
        return
    }
    defer etcdCli.Close()

    for {
        ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
        resp, err := etcdCli.Get(ctx, *conf.EtcdKey)
        if err != nil {
            logx.Errorf("err: %v", err)
            cancel()
            continue
        }
        if len(resp.Kvs) == 1 {
            var configMap map[string]string
            err = json.Unmarshal(resp.Kvs[0].Value, &configMap)
            if err != nil {
                logx.Errorf("err: %v", err)
            } else {
                cacheConfigMap.Lock()
                cacheConfigMap.data = configMap
                cacheConfigMap.Unlock()
                logx.Info("Refresh config success")
            }
        }
        cancel()
        time.Sleep(time.Second * 10)
    }
}

func Lock() error {
    etcdCli, err := clientv3.New(clientv3.Config{
        Endpoints:   *conf.Etcd,
        DialTimeout: time.Second * 3,
    })
    if err != nil {
        logx.Errorf("err: %v", err)
        return err
    }
    defer etcdCli.Close()

    var s *concurrency.Session
    var m *concurrency.Mutex
    for {
        opTimeoutCtx, cancel := context.WithTimeout(context.Background(), time.Second)
        s, err = concurrency.NewSession(etcdCli,
            concurrency.WithContext(opTimeoutCtx),
            concurrency.WithTTL(int32(*conf.LockTtl)))
        if err != nil {
            logx.Errorf("create etcd session error: %v", err)
            cancel()
            time.Sleep(time.Second)
            continue
        }

        opTimeoutCtx, cancel = context.WithTimeout(context.Background(), time.Second)
        m = concurrency.NewMutex(s, *conf.EtcdKey)
        err = m.Lock(opTimeoutCtx)
        if err != nil {
            logx.Errorf("etcd lock failed: %v", err)
            cancel()
            time.Sleep(time.Second)
            continue
        }
        break
    }

    cacheConfigMap.Lock()
    defer cacheConfigMap.Unlock()

    defer func() {
        if m != nil {
            err = m.Unlock(context.Background())
            if err != nil {
                logx.Errorf("etcd unlock failed: %v", err)
            }
        }
    }()
    defer func() {
        if s != nil {
            s.Close()
        }
    }()
    return nil
}