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

node-ral with mcpack and nshead

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

'use strict';

var ConfigNormalizer = require('node-ral').ConfigNormalizer;
var CTX = require('node-ral/lib/ctx');
var util = require('util');
var logger = require('node-ral').Logger('BNSNormalizer');
var bns;
var bnsCache = {};

function lazyFetchFromBNSCache(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_instance_by_service_async && bnsCache[bnsName]) {
        bns.get_instance_by_service_async(bnsName).then(ret => {
            logger.trace('cache updated by get_service_conf_async ' + bnsName);
            bnsCache[bnsName] = ret;
        }).catch(err => {
            logger.warning("BNS " + bnsName + " aysnc update failed: " + err);
        });
        return bnsCache[bnsName];
    }
    var ret = bns.get_instance_by_service(bnsName);
    if (ret.error === -1) {
        throw new Error('bns fetch failed bns=' + bnsName);
    }
    bnsCache[bnsName] = ret;
    return bnsCache[bnsName];
}

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

util.inherits(BNSNormalizer, ConfigNormalizer);

BNSNormalizer.prototype._prepareIDCMap = function (config) {
    // 准备 idc_map 映射表，不支持backup
    var reMap;
    if (config.idc_map) {
        reMap = {};
        var currentIDCMap = config.idc_map[CTX.currentIDC] || config.idc_map['default'] || {};
        if (currentIDCMap.prefer) {
            var prefers;
            if (currentIDCMap.prefer instanceof Array === false) {
                prefers = [currentIDCMap.prefer];
            }
            else {
                prefers = currentIDCMap.prefer;
            }
            prefers.forEach(function (prefer) {
                if (prefer === 'self' && CTX.currentIDC) {
                    prefer = CTX.currentIDC;
                }
                reMap[prefer] = true;
            });
        }
    }
    return reMap;
};

BNSNormalizer.prototype._remapIDC = function (serverInfo, idcMap, defaultIDC, hybird) {
    if (defaultIDC) {
        return defaultIDC;
    }
    // try get idc from bns
    var serverIDC;
    // server idc should override bns idc config
    // if (serverInfo.tag) {
    //     serverInfo.tag.split(',').forEach(function (item) {
    //         var pair = item.split(':');
    //         if (pair.length === 2 && pair[0] === 'idc') {
    //             serverIDC = pair[1];
    //         }
    //     });
    // }
    if (!hybird && serverInfo.service_name) {
        var serviceIDC = serverInfo.service_name.split('.').pop();
        // 根据 idcMap 重新设置服务的IDC
        if (idcMap && (idcMap[serviceIDC] || idcMap.all)) {
            serverIDC = CTX.currentIDC;
        }
        else {
            serverIDC = serviceIDC;
        }
    }
    return serverIDC;
};

BNSNormalizer.prototype.normalizeConfig = function (config) {
    var normalizedServer = [];
    var me = this;

    var idcMap = this._prepareIDCMap(config);

    for (var i = config.server.length - 1; i >= 0; i--) {
        var server = config.server[i];
        if (server.bns) {
            var bnsServerList = [];
            var instanceRet = lazyFetchFromBNSCache(server.bns);
            instanceRet.forEach(function (serverInfo) {
                if (serverInfo.status === 0) {
                    var serverIDC = me._remapIDC(serverInfo, idcMap, server.idc, config.hybird) || 'all';
                    bnsServerList.push({
                        host: serverInfo.ip || serverInfo.host,
                        hostname: serverInfo.host,
                        port: serverInfo.port,
                        idc: serverIDC
                    });
                }
            });
            normalizedServer = normalizedServer.concat(bnsServerList);
            logger.trace(server.bns + ' bns config is updated');
        }
        else {
            normalizedServer.push(server);
        }
    }
    if (normalizedServer.length !== 0) {
        config.server = normalizedServer;
    }
    else {
        logger.warning(server.bns + ' bns config update failed, got no server');
    }
    return config;
};

BNSNormalizer.prototype.getName = function () {
    return 'bns';
};

BNSNormalizer.prototype.needUpdate = function (config) {
    if (config.server) {
        for (var i = 0; i < config.server.length; i++) {
            if (config.server[i].bns) {
                return true;
            }
        }
    }
};

module.exports = BNSNormalizer;