0.2.0 resilitient master process architecture change

app.js

@@ -40,12 +40,14 @@ function processUncaughtExceptionListener() {
 	log(processName, 'uncaughtException')
 	var text = []
 	Array.prototype.slice.call(arguments).forEach(function (value, index) {
-		var line = []
+		var valuePoints = []
 		var type = typeof value
 		if (value && value.constructor && value.constructor.name) type += ':' + value.constructor.name
-		line.push('arg#:', index, 'type:', type, 'value:', value)
-		if (value && value.stack) line.push('stack:', value.stack)
-		text.push(line.join(' '))
+		valuePoints.push(['arg#:', index].join(' '))
+		valuePoints.push(['type:', type].join(' '))
+		valuePoints.push(['value:', value].join(' '))
+		if (value && value.stack) valuePoints.push(['stack:', value.stack].join(' '))
+		text.push(valuePoints.join(', '))
 	})
 	log(text.join('\n'))
 }

lib/master/rotatedlogger.js

@@ -15,22 +15,32 @@ init, log, write
 ].forEach(function (f) {exports[f.name] = f})
 
 var writeStreamFlags = {
-	flags: 'a', encoding: 'utf-8', mode: 0660,
+	flags: 'a', encoding: 'utf-8', mode: 0660, // rw- rw- ---
 }
-var logSubfolder = 'log'
+var logSubfolder = 'log' // subfolder of user's home folder
 var logFileExt = '.log'
-var logFile = 'applog'
+var logFile = 'applog' // default log file basename
 var rotateSchedule = 'month'
+var logToFile // boolean default false
 
-var logToFile
+// flags for output error occured
 var writeStreamIsError
+var stdoutIsError
+
 var logToFileEnabled // affected by writeStreamIsError and logToFile
 var logFilename
 var writeStream
-var stdoutIsError
 var periodTimer
 var streamBuffer
 
+/*
+Configure rotatedlogger
+opts: optional object
+.writeStreamFlags: optional object: custom second argument to createWriteStream for the log file
+.logSubfolder: optional string subfolder of user's home folder for log files, null for logFile being full qualified filename
+.logFile: optional string set basename or full name of log file
+.logToFile: optional boolean default false: enable logging to file
+*/
 function init(opts) {
 	var result = {
 		writeStreamFlags: {},
@@ -74,7 +84,12 @@ function write(str) {
 		if (streamBuffer) streamBuffer.push(str)
 		else {
 			if (!writeStream) openStream()
-			writeStream.write(str)
+			try {
+				writeStream.write(str)
+			} catch (e) { // error written by stream error listener
+				writeStreamIsError = true
+				logToFileEnabled = false
+			}
 		}
 	}
 }

lib/pidlink.js

@@ -8,7 +8,6 @@ var greatjson = require('greatjson')
 var fs = require('fs')
 // http://nodejs.org/api/path.html
 var path = require('path')
-if (!fs.exists) fs.exists = path.exists
 
 ;[
 init, getData
@@ -23,18 +22,19 @@ var signal = 'SIGUSR2'
 var folder
 var log = console.log
 
-// this file is not an api, though we can have apprunner monitor errors
-var require = require('apprunner').getRequire(require, null, {api: 'pidlink',})
+// get error emitter without being an api
+var r = require; var require = require('apprunner').getRequire(r, null, {emScope: 'pidlink',})
 
 /*
-configure this api
-folder0: optional string: fully qualified pathname to a folder where pid files will be read and written
-signal0: optional string, default 'SIGURS2' the signal sent to pid
-initialWait0: optional number, default 2,000 ms: the time to wait before sending signal
-waitTime0: optional number, default 500 ms: the time to wait between signal and file read
-log: function to be used for printing
-
-the responder is in the apprunner module's appshutdown file.
+Configure pidlink
+opts: optional object
+.folder: optional string: fully qualified pathname to a folder where pid files will be read and written
+.signal: optional string, default 'SIGURS2' the signal sent to pid
+.initialWait: optional number, default 2,000 ms: the time to wait before sending signal
+.waitTime: optional number, default 500 ms: the time to wait between signal and file read
+.log: optional function used for printing
+
+The signal handler in the other process is the apprunner module's appshutdown file.
 */
 function init(opts) {
 	var result = {
@@ -56,14 +56,16 @@ function init(opts) {
 /*
 Get data from another process
 pid: positive number: process id for the other process
-slogan: optional string decsribing the pid process
+slogan: optional string decsribing the other process
 cb(err, result) function, result: object from json parsing
 
 Wait for 2 seconds to allow the other app time to start properly
-send a signal to the process and it will write a file to the filesystem
-wait 0.5 seconds to read the result
-best effort: if process can't be found or non-init, return undefined result
-tmpfolder is used, files are named using the pid with '.json' extension
+Send a signal to the process causing it to write a file to the filesystem
+Wait 0.5 seconds to read the result
+Return data from the file
+
+If process can't be found or does not write the file, reult has undefined value
+Files are in tmpfolder, named using the process id number and a '.json' extension
 */
 function getData(pid, slogan, cb) {
 	var result
@@ -101,30 +103,30 @@ function getData(pid, slogan, cb) {
 		fs.readFile(file, readResult)
 	}
 
-	function readResult(err, data) {
-		if (!err) {
+	function readResult(e, data) {
+		if (!e) {
 			var obj = greatjson.parse(data)
-			if (!(obj instanceof Error)) {
-				result = obj
-				fs.unlink(file, end)
-			} else end(obj)
+			if (!(obj instanceof Error)) result = obj
+			else err = obj // saving parsing trouble
+			fs.unlink(file, end)
 		} else {
-			if (err.code == 'ENOENT') {
+			if (e.code == 'ENOENT') {
 				log('No data written by:', otherProcess)
 				end()
-			} else end(err)
+			} else end(e)
 		}
 	}
 
-	function end(err) {
-		if (!err) cb(null, result)
+	function end(e) {
+		if (!e && err) e = err // pick up saved error
+		if (!e) cb(null, result) // good return
 		else {
-			require.emitter.emit.apply(require.emitter, ['error', err, {
+			require.emitter.emit.apply(require.emitter, ['error', e, {
 				invocation: invocation,
 				pid: pid,
 				slogan: slogan,
 			}].concat(Array.prototype.slice.call(arguments).slice(1)))
-			cb(err)
+			cb(e) // bad return
 		}
 	}
 }

package.json

@@ -8,7 +8,7 @@
 		"node",
 		"operations"
 	],
-	"version": "0.1.5",
+	"version": "0.2.0",
 	"contributors": [
 		{
 			"name": "Harald Rudell",

test/test-app.js

@@ -2,8 +2,11 @@
 // © Harald Rudell 2012
 
 var processfinder = require('../lib/master/processfinder')
+
 var uimanager = require('../lib/master/uimanager')
 var rotatedlogger = require('../lib/master/rotatedlogger')
+// http://nodejs.org/api/path.html
+var path = require('path')
 
 // https://github.com/haraldrudell/mochawrapper
 var assert = require('mochawrapper')
@@ -13,16 +16,14 @@ var sru = processfinder.setResetUi
 var ipm = processfinder.isProcessMaster
 var lui = uimanager.launchUi
 var gur = uimanager.getUiRelauncher
-
 var lg = rotatedlogger.log
 
 exports['App:'] = {
 	'IsNotMaster ProcessException SIGINT IsMaster': function() {
 
-
 		// execute is not master
 		var aOn = {}
-		var eOn = ['uncaughtException', 'SIGUSR2', 'SIGINT']
+		var eOn = ['uncaughtException', 'SIGUSR2', 'SIGINT', 'SIGHUP']
 		process.on = function (e, f) {aOn[e] = f; return this}
 		var aIsProcessMaster = []
 		var eIsProcessMaster = [[{port: 1113, interface: '127.0.0.1', processName: 0}, 'cb']]
@@ -51,23 +52,26 @@ exports['App:'] = {
 
 		// execute is master
 		var masterResult = aIsProcessMaster[0][1]
+
 		process.on = function () {}
 		processfinder.isProcessMaster = function (o, cb) {cb(true)}
+
 		var uiRelauncher = 5
 		uimanager.getUiRelauncher = function () {return uiRelauncher}
+
 		var aReset = []
 		var eReset = [uiRelauncher]
 		processfinder.setResetUi = function (f) {aReset.push(f)}
+
 		var aLaunchUi = []
-		var eLaunchUi = [{uiModuleName: 'webprocess'}]
+		var eLaunchUi = [{processName: 'x', launchArray: ['node', path.join(__dirname, '..', 'webprocess')], log: 'x'}]
 		uimanager.launchUi = function (opts) {aLaunchUi.push(opts)}
 		masterResult(true)
 
 		assert.deepEqual(aReset, eReset)
-		assert.equal(aLaunchUi.length, 1)
-		assert.equal(typeof aLaunchUi[0].log, 'function')
-		assert.equal(typeof aLaunchUi[0].processName, 'string')
-		assert.equal(aLaunchUi[0].uiModuleName, 'webprocess')
+		assert.equal(typeof (eLaunchUi[0].processName = aLaunchUi[0] && aLaunchUi[0].processName), 'string')
+		assert.equal(typeof (eLaunchUi[0].log = aLaunchUi[0] && aLaunchUi[0].log), 'function')
+		assert.deepEqual(aLaunchUi, eLaunchUi)
 	},
 	'after': function() {
 		process.on = on

test/test-appconduit.js

@@ -56,16 +56,6 @@ exports['AppConduit:'] = {
 		eData[0].launchTime = aData[0].launchTime
 		assert.deepEqual(aData, eData)
 	},
-	'ReceiveFromUi Launch Non-Array': function() {
-		// launch non-array
-		var message = {app: 'APP', launch: true}
-		var aData = []
-		var eData = [{error: 'Bad launch command', isConfig: true, message: {app: message.app}}]
-		appconduit.uiConnect(function (d) {aData.push(d)})
-		appconduit.receiveFromUi(message)
-
-		assert.deepEqual(aData, eData)
-	},
 	'ReceiveFromUi Launch': function(done) {
 
 		// launch
@@ -84,7 +74,7 @@ exports['AppConduit:'] = {
 		var eSpawn = [[
 			message.launch[0],
 			[message.launch[1]],
-			['ignore', 'pipe', 'pipe'],
+			{detached: true, stdio: ['ignore', 'pipe', 'pipe']},
 		]]
 		child_process.spawn = function (command, args, options) {aSpawn.push([command, args, options]); return child}
 		appconduit.receiveFromUi(message)
@@ -202,6 +192,16 @@ exports['AppConduit:'] = {
 		var aMap = appconduit.getState()
 		assert.deepEqual(aMap, eMap)
 	},
+	'ReceiveFromUi Launch Non-Array': function() {
+		// launch non-array
+		var message = {app: 'APP', launch: true}
+		var aData = []
+		var eData = [{error: 'Bad launch command', isConfig: true, message: {app: message.app}}]
+		appconduit.uiConnect(function (d) {aData.push(d)})
+		appconduit.receiveFromUi(message)
+
+		assert.deepEqual(aData, eData)
+	},
 	'after': function() {
 		child_process.spawn = sp
 		process.kill = pk

test/test-rotatedlogger.js

@@ -22,28 +22,33 @@ exports['RotatedLogger:'] = {
 		var actual = rotatedlogger.init()
 		assert.ok(actual)
 	},
-	'Write': function () {
-		var value = '123'
-		var eValue = value + '\n'
+	'Write Log': function () {
+		var value = ['value: %s', 123]
+		var eValue = 'value: ' + value[1] + '\n'
 
 		var aWrite = []
 		var eWrite = [eValue, eValue]
 		function mockWrite(x) {aWrite.push(x)}
 
 		var aOn = {}
+		var eOn = ['error']
 		function mockOn(e, f) {aOn[e] = f; return this}
 		fs.createWriteStream = function mockCreateWriteStream(x) {return {on: mockOn, write: mockWrite}}
 
-		var aTe = 0
-		perioder.TimeEmitter = function MockTimeEmitter() {this.on = function () {}; aTe++}
-
+		var aTOn = []
+		var eTOn = ['time']
+		perioder.TimeEmitter = function MockTimeEmitter() {this.on = function (e, f) {aTOn[e] = f}}
 
 		process.stdout.write = mockWrite
-		rotatedlogger.log(value)
+		rotatedlogger.init({logToFile: true})
+		rotatedlogger.log(value[0], value[1])
 		process.stdout.write = wr
+
 		assert.deepEqual(aWrite, eWrite)
-		assert.ok(aTe)
-		assert.equal(typeof aOn.error, 'function')
+		assert.deepEqual(Object.keys(aOn).sort(), eOn.sort())
+		for (var e in aOn) assert.equal(typeof aOn[e], 'function')
+		assert.deepEqual(Object.keys(aTOn).sort(), eTOn.sort())
+		for (var e in aTOn) assert.equal(typeof aTOn[e], 'function')
 	},
 	'after': function () {
 		process.stdout.write = wr

test/test-uimanager.js

@@ -31,7 +31,7 @@ exports['UiManager:'] = {
 
 		// launch
 		var processName = 'PROCESS_NAME'
-		var uiModuleName = 'UI_MODULE_NAME'
+		var launchArray = ['EXECUTABLE', 'ARGUMENT']
 		var aLaunchData = []
 		var eLaunchData = [[processName, 0]]
 		appconduit.setLaunchData = function (p, u) {aLaunchData.push([p, u])}
@@ -42,9 +42,9 @@ exports['UiManager:'] = {
 		var child = {pid:17, on: onFn, once: onFn, send: childSend}
 		var aSpawn = []
 		var eSpawn = [[
-			'node',
-			[path.join(path.dirname(require && require.main && require.main.filename), uiModuleName)],
-			{stdio: ['ignore', 'pipe', 'pipe', 'ipc']},
+			launchArray[0],
+			launchArray.slice(1),
+			{detached: true, stdio: ['ignore', 'pipe', 'pipe', 'ipc']},
 		]]
 		child_process.spawn = function mockSpawn(c, a, o) {aSpawn.push([c, a, o]); return child}
 		var aLog = []
@@ -54,7 +54,7 @@ exports['UiManager:'] = {
 		appconduit.uiConnect = function (f) {aUiConnect.push(f)}
 		var aException = []
 		var restartIntercept = function (e) {aException.push(e)}
-		uimanager.launchUi({processName: processName, uiModuleName: uiModuleName, restartIntercept: restartIntercept, log: function () {}})
+		uimanager.launchUi({processName: processName, launchArray: launchArray, restartIntercept: restartIntercept, log: function () {}})
 
 		assert.deepEqual(aException, [], 'launchUi exceptions')
 		assert.ok(aLaunchData[0])