yog-ral/lib/ext/normalizer/webfoot.js

node-ral with mcpack and nshead

/*
 * fis
 * http://fis.baidu.com/
 * 2014/8/20
 */

'use strict';

var ConfigNormalizer = require('node-ral').ConfigNormalizer;
var util = require('util');
var logger = require('node-ral').Logger('WebfootNormalizer');
var bns;
var webfootCache = {};

function lazyFetchFromWebfootCache(bnsName) {
    bns = bns || require('@baidu/bns');
    // 初期调用时使用同步获取服务器配置
    if (bns.get_service_conf_async && webfootCache[bnsName]) {
        bns.get_service_conf_async(bnsName).then(ret => {
            logger.trace('cache updated by get_service_conf_async ' + bnsName);
            webfootCache[bnsName] = ret;
        }).catch(err => {
            logger.warning("BNS " + bnsName + " aysnc update failed: " + err);
        });
        return webfootCache[bnsName];
    }
    var ret = bns.get_service_conf(bnsName);
    if (ret.error === -1) {
        throw new Error('bns fetch failed bns=' + bnsName);
    }
    webfootCache[bnsName] = ret;
    return webfootCache[bnsName];
}

function WebfootNormalizer() {
    ConfigNormalizer.call(this);
}

util.inherits(WebfootNormalizer, ConfigNormalizer);

WebfootNormalizer.prototype.normalizeConfig = function (config) {
    if (!config.webfoot) {
        return config;
    }
    var bnsConf = lazyFetchFromWebfootCache(config.webfoot);
    if (!bnsConf) {
        throw new Error('webfoot ' + config.webfoot + ' load failed');
    }
    bnsConf = JSON.parse(bnsConf);
    if (bnsConf.error) {
        throw new Error('webfoot ' + config.webfoot + ' load failed, error:' + bnsConf.error);
    }
    var conf = this._translate(config.webfoot, bnsConf);
    var keys = Object.keys(config);
    for (var i = 0; i < keys.length; i++) {
        if (config[keys[i]] !== null) {
            conf[keys[i]] = config[keys[i]];
        }
    }
    logger.trace(config.webfoot + ' webfoot config is updated');
    return conf;
};

WebfootNormalizer.prototype.getName = function () {
    return 'webfoot';
};

WebfootNormalizer.prototype.needUpdate = function (config) {
    if (config.webfoot) {
        return true;
    }
};

WebfootNormalizer.prototype._translate = function (webfootName, bnsConfig) {
    var service = bnsConfig.services[webfootName];
    if (!service) {
        throw new Error('invalid webfoot info, webfoot: ' + webfootName);
    }
    var unpack = service.converter.name;
    //webfoot兼容，只有mcpack2与json数据打包协议使用本协议进行解包，其余协议均使用string解包
    if (['protobuf', 'msgpack', 'mcpack2', 'json'].indexOf(unpack) === -1) {
        unpack = 'string';
    }
    var conf = {
        unpack: unpack,
        pack: service.converter.name,
        balance: 'random',
        protocol: service.protocol.name,
        retry: parseInt(service.service_retry, 10) || 0,
        timeout: service.service_ctimeout + service.service_rtimeout + service.service_wtimeout,
        headers: service.Headers || {},
        server: [{
            bns: webfootName
        }],
        idc_map: service.idc_map
    };
    return conf;
};

module.exports = WebfootNormalizer;