ca-apm-probe/lib/probename-resolver.js

CA APM Node.js Agent monitors real-time health and performance of Node.js applications

/**
 * Copyright (c) 2015 CA. All rights reserved.
 *
 * This software and all information contained therein is confidential and proprietary and
 * shall not be duplicated, used, disclosed or disseminated in any way except as authorized
 * by the applicable license agreement, without the express written permission of CA. All
 * authorized reproductions must be marked with this language.
 *
 * EXCEPT AS SET FORTH IN THE APPLICABLE LICENSE AGREEMENT, TO THE EXTENT
 * PERMITTED BY APPLICABLE LAW, CA PROVIDES THIS SOFTWARE WITHOUT WARRANTY
 * OF ANY KIND, INCLUDING WITHOUT LIMITATION, ANY IMPLIED WARRANTIES OF
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL CA BE
 * LIABLE TO THE END USER OR ANY THIRD PARTY FOR ANY LOSS OR DAMAGE, DIRECT OR
 * INDIRECT, FROM THE USE OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, LOST
 * PROFITS, BUSINESS INTERRUPTION, GOODWILL, OR LOST DATA, EVEN IF CA IS
 * EXPRESSLY ADVISED OF SUCH LOSS OR DAMAGE.
 */

var config = require('../config.json');
var path = require('path');
var util = require('./utils/common-utils');

var probeName = null;
var buffer = {info: [], debug: []};

function initialize(options){

	buffer.debug.push("options available before resolving ProbeName: " + JSON.stringify(options));
	
	var probeName = [];
	
	// Step 1: agent name from env variable
	probeName[0] = process.env.CA_APM_PROBENAME || process.env.APM_ENV_PROBENAME;
	buffer.debug.push("Step 1:  env= "+probeName[0]);
		
	// Step 2: agent name from user specified env variable
	var key = config.probeNameEnvKey;
	probeName[1] = process.env[key];
	buffer.debug.push("Step 2:  env= "+probeName[1]);
		
	// Step 3: agent name from application code
	probeName[2] = options.probeName;
	buffer.debug.push("Step 3:  code= "+probeName[2]);
		
	// Step 4: agent name from ca-apm-probe config.json
	probeName[3] = util.resolveEnv(config.probeName);
	buffer.debug.push("Step 4:  probe config.json= "+ probeName[3]);
		
	// Step 5: agent name from application mainModule package.json, if it exists
	var appScriptFilename = process.mainModule.filename;
	if (options.appScriptName) {
		appScriptFilename = options.appScriptName;
	}
	var appPackage;
	try {
		appPackage = require(path.join(path.dirname(appScriptFilename),'package.json'));
	} catch (error) {
	}
	if (appPackage) {
		probeName[4] = appPackage.name;
		if(appPackage.dependencies) {
			var appVersions = JSON.stringify(appPackage.dependencies);
			options.appVersions = appVersions;
		}
	}
	buffer.debug.push("Step 5:  app package.json= "+ probeName[4]);
		
	// Step 6: agent name from application start script
	probeName[5] = path.basename(appScriptFilename, '.js');
	buffer.debug.push("Step 6:  script= " + probeName[5]);
		
	// Step 7: agent name from application start dir
	probeName[6] = path.dirname(appScriptFilename).split(path.sep).slice(-1)[0];
	buffer.debug.push("Step 7:  dir= " + probeName[6]);
	
	for (var i = 0; i < probeName.length; i++) {
		if (probeName[i] && probeName[i].length > 0 && probeName[i] != 'index') {
			buffer.info.push("ProbeName Detection choosing the name: "+ probeName[i]);
			return probeName[i];
		}
	};
	// Final hardcoded fallback, we should never get here.
	return 'NodeApplication';
}

function setProbeName(probeNameArg) {
	probeName = probeNameArg;
}

function getProbeName() {
	return probeName;
}

function getBuffer() {
	return buffer;
}

module.exports = {initialize: initialize, setProbeName: setProbeName, getProbeName: getProbeName, getBuffer: getBuffer};