acm-client
Version:
aliyun acm client
220 lines • 7.46 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const snapshot_1 = require("./snapshot");
const const_1 = require("./const");
const Base = require('sdk-base');
const debug = require('debug')('diamond-client');
const path = require('path');
const assert = require('assert');
const gather = require('co-gather');
const Constants = require('./const');
const { random } = require('utility');
const { sleep } = require('mz-modules');
const DEFAULT_OPTIONS = {
endpoint: 'acm.aliyun.com',
refreshInterval: 30 * 1000,
};
class ServerListManager extends Base {
/**
* 服务地址列表管理器
*
* @param {Object} options
* - {HttpClient} httpclient - http 客户端
* - {Snapshot} [snapshot] - 快照对象
* - {String} nameServerAddr - 命名服务器地址 `hostname:port`
* @constructor
*/
constructor(options) {
assert(options.httpclient, '[diamond#ServerListManager] options.httpclient is required');
options.snapshot = options.snapshot || new snapshot_1.Snapshot(options);
if (options.endpoint) {
const temp = options.endpoint.split(':');
options.endpoint = temp[0] + ':' + (temp[1] || '8080');
}
super(Object.assign({}, DEFAULT_OPTIONS, options));
this.isSync = false;
this.isClosed = false;
this.currentUnit = const_1.CURRENT_UNIT;
this.serverListCache = new Map(); // unit => { hosts: [ addr1, addr2 ], index }
this.syncServers();
this.ready(true);
}
get snapshot() {
return this.options.snapshot;
}
get httpclient() {
return this.options.httpclient;
}
get nameServerAddr() {
if (this.options.endpoint) {
return this.options.endpoint;
}
return this.options.nameServerAddr;
}
get refreshInterval() {
return this.options.refreshInterval;
}
/**
* 关闭地址列表服务
*/
close() {
this.isClosed = true;
}
async request(url, options) {
const res = await this.httpclient.request(url, options);
const { status, data } = res;
if (status !== 200) {
const err = new Error(`[diamond#ServerListManager] request url: ${url} failed with statusCode: ${status}`);
err.name = 'DiamondServerResponseError';
err.url = url;
err.params = options;
err.body = res.data;
throw err;
}
return data;
}
/*
* 获取当前机器所在单元
*/
async getCurrentUnit() {
if (!this.currentUnit) {
const url = `http://${this.nameServerAddr}/env`;
const data = await this.request(url, {
timeout: this.options.requestTimeout,
dataType: 'text',
});
const unit = data && data.trim();
this.currentUnit = unit;
}
return this.currentUnit;
}
/**
* 获取某个单元的地址
* @param {String} unit 单元名，默认为当前单元
* @return {String} address
*/
async getOne(unit = Constants.CURRENT_UNIT) {
let serverData = this.serverListCache.get(unit);
// 不存在则先尝试去更新一次
if (!serverData) {
serverData = await this.fetchServerList(unit);
}
// 如果还没有，则返回 null
if (!serverData || !serverData.hosts.length) {
return null;
}
const choosed = serverData.hosts[serverData.index];
serverData.index += 1;
if (serverData.index >= serverData.hosts.length) {
serverData.index = 0;
}
return choosed;
}
/**
* 同步服务器列表
* @return {void}
*/
syncServers() {
if (this.isSync) {
return;
}
(async () => {
try {
this.isSync = true;
while (!this.isClosed) {
await sleep(this.refreshInterval);
const units = Array.from(this.serverListCache.keys());
debug('syncServers for units: %j', units);
const results = await gather(units.map(unit => this.fetchServerList(unit)));
for (let i = 0, len = results.length; i < len; i++) {
if (results[i].isError) {
const err = new Error(results[i].error);
err.name = 'DiamondUpdateServersError';
this.emit('error', err);
}
}
}
this.isSync = false;
}
catch (err) {
this.emit('error', err);
}
})();
}
// 获取某个单元的 diamond server 列表
async fetchServerList(unit = Constants.CURRENT_UNIT) {
const key = this.formatKey(unit);
const url = this.getRequestUrl(unit);
let hosts;
try {
let data = await this.request(url, {
timeout: this.options.requestTimeout,
dataType: 'text',
});
data = data || '';
hosts = data.split('\n').map(host => host.trim()).filter(host => !!host);
const length = hosts.length;
debug('got %d hosts, the serverlist is: %j', length, hosts);
if (!length) {
const err = new Error('[diamond#ServerListManager] Diamond return empty hosts');
err.name = 'DiamondServerHostEmptyError';
err.unit = unit;
throw err;
}
await this.snapshot.save(key, JSON.stringify(hosts));
}
catch (err) {
this.emit('error', err);
const data = await this.snapshot.get(key);
if (data) {
try {
hosts = JSON.parse(data);
}
catch (err) {
await this.snapshot.delete(key);
err.name = 'ServerListSnapShotJSONParseError';
err.unit = unit;
err.data = data;
this.emit('error', err);
}
}
}
if (!hosts || !hosts.length) {
// 这里主要是为了让后面定时同步可以执行
this.serverListCache.set(unit, null);
return null;
}
const serverData = {
hosts,
index: random(hosts.length),
};
this.serverListCache.set(unit, serverData);
return serverData;
}
formatKey(unit) {
return path.join('server_list', unit);
}
// 获取请求 url
getRequestUrl(unit) {
return unit === Constants.CURRENT_UNIT ?
`http://${this.nameServerAddr}/diamond-server/diamond` :
`http://${this.nameServerAddr}/diamond-server/diamond-unit-${unit}?nofix=1`;
}
/**
* 获取单元列表
* @return {Array} units
*/
async fetchUnitLists() {
return [this.currentUnit];
}
// for test
hasServerInCache(serverName) {
return this.serverListCache.has(serverName);
}
// for test
clearaServerCache() {
this.serverListCache.clear();
}
}
exports.ServerListManager = ServerListManager;
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