apminsight/lib/communication/reqhandler.js

monitor nodejs applications

var constants = require("./../constants");
var https = require("https");
var utils = require("./../util/utils");
var logger = require("./../util/logger");
const { URL } = require('url');

function sendToCollector(uri, postData, cb) {
    var config = apmInsightAgentInstance.getConfig();
    var insInfo = apmInsightAgentInstance.getInsInfo();
    const endPoints = config.getApmHosts();
    const tryEndpoint = (index) => {
        if(index >= endPoints.length){
            cb(new Error('All endpoints failed'), uri);
            return;
        }
        let fullPath = `${uri}?${constants.licenseKey}=${config.getLicenseKey()}`;
        if (!utils.isEmpty(insInfo.getInstanceId())) {
            fullPath += `&${constants.instance_Id}=${insInfo.getInstanceId()}`;
        }
        const url = new URL(endPoints[index]);
        var connectInfo = {
            host: url.hostname,
            port: url.port || (url.protocol === 'https:' ? constants.collectorPort : constants.httpPort),
            path: fullPath,
            method: constants.requestMethod,
            rejectUnauthorized: false,
            headers: {
                "Content-Type": "application/json",
                "Content-Length": Buffer.byteLength(postData)
            }
        };
        config.checkAndAddProxyAgent(connectInfo);
        sendRequest(uri, connectInfo, postData, (error, uri, responseData) => {
            if(error){
                logger.info(`while initiating req to ${uri}, endpoint ${endPoints[index]}, failed: ${error.message} moving onto next endpoint`);
                tryEndpoint(index + 1);
                return;
            }else{
                cb(null, uri, responseData || undefined);
            }
        });
    }
    // Start with the first endpoint
    tryEndpoint(0);
}

function sendRequest(uri, connectInfo, postData, cb) {
    var payload = apmInsightAgentInstance.getConfig().isPrintPayloadEnabled()
        ? " with payload " + postData
        : "";
    logger.info(
        "intiating " +
            uri +
            " request to " +
            connectInfo.host +
            ":" +
            connectInfo.port +
            payload
    );
    var req = https.request(connectInfo, function (response) {
        response.setEncoding("utf8");
        var rawData = "";
        response.on("data", function (chunk) {
            rawData += chunk;
        });

        response.on("end", function () {
            try {
                if(response.statusCode >= 200 && response.statusCode < 300){
                    if (utils.isEmpty(rawData)) {
                        cb(false, uri);
                        return;
                    }
                    const responseData = JSON.parse(rawData);
                    cb(false, uri, responseData);
                }
            } catch (e) {
                cb(e, uri);
            }
        });
    });

    req.on("error", function (error) {
        cb(error, uri);
    });

    req.write(postData);
    req.end();
}

module.exports = {
    sendToCollector: sendToCollector,
    sendRequest: sendRequest
};