node-ral-huskar/lib/getProxyFromURI.js

a rpc client for node

/**
 * @file node-ral 根据URL获取proxy
 * @author hefangshi@baidu.com
 */

'use strict';

function formatHostname(hostname) {
    // canonicalize the hostname, so that 'oogle.com' won't match 'google.com'
    return hostname.replace(/^\.*/, '.').toLowerCase();
}

function parseNoProxyZone(zone) {
    zone = zone.trim().toLowerCase();

    var zoneParts = zone.split(':', 2);
    var zoneHost = formatHostname(zoneParts[0]);
    var zonePort = zoneParts[1];
    var hasPort = zone.indexOf(':') > -1;

    return {
        hostname: zoneHost,
        port: zonePort,
        hasPort: hasPort
    };
}

function uriInNoProxy(uri, noProxy) {
    var port = uri.port || (uri.protocol === 'https:' ? '443' : '80');
    var hostname = formatHostname(uri.hostname);
    var noProxyList = noProxy.split(',');

    // iterate through the noProxyList until it finds a match.
    return noProxyList.map(parseNoProxyZone).some(function (noProxyZone) {
        var isMatchedAt = hostname.indexOf(noProxyZone.hostname);
        var hostnameMatched = (
            isMatchedAt > -1
            && (isMatchedAt === hostname.length - noProxyZone.hostname.length)
        );

        if (noProxyZone.hasPort) {
            return (port === noProxyZone.port) && hostnameMatched;
        }

        return hostnameMatched;
    });
}

function getProxyFromURI(uri) {
    // Decide the proper request proxy to use based on the request URI object and the
    // environmental variables (NO_PROXY, HTTP_PROXY, etc.)
    // respect NO_PROXY environment variables (see: http://lynx.isc.org/current/breakout/lynx_help/keystrokes/environments.html)

    var noProxy = process.env.NO_PROXY || process.env.no_proxy || '';

    // if the noProxy is a wildcard then return null

    if (noProxy === '*') {
        return null;
    }

    // if the noProxy is not empty and the uri is found return null

    if (noProxy !== '' && uriInNoProxy(uri, noProxy)) {
        return null;
    }

    // Check for HTTP or HTTPS Proxy in environment Else default to null

    if (uri.protocol === 'http:') {
        return process.env.HTTP_PROXY || process.env.http_proxy || null;
    }

    if (uri.protocol === 'https:') {
        return process.env.HTTPS_PROXY || process.env.https_proxy
        || process.env.HTTP_PROXY || process.env.http_proxy || null;
    }

    // if none of that works, return null
    // (What uri protocol are you using then?)

    return null;
}

module.exports = getProxyFromURI;