appcelerator/lib/download.js

/**
 * This code is closed source and Confidential and Proprietary to
 * Appcelerator, Inc. All Rights Reserved.  This code MUST not be
 * modified, copied or otherwise redistributed without express
 * written permission of Appcelerator. This file is licensed as
 * part of the Appcelerator Platform and governed under the terms
 * of the Appcelerator license agreement.
 */
var ProgressBar = require('progress'),
	chalk = require('chalk'),
	util = require('./util'),
	errorlib = require('./error'),
	urllib = require('url'),
	fs = require('fs'),
	os = require('os'),
	path = require('path'),
	debug = require('debug')('appc:download'),
	tmpdir = os.tmpdir(),
	MAX_RETRIES = 10,
	pendingRequest;

function download(quiet, force, wantVersion, tmpfile, stream, location, callback, nobanner, retryAttempts) {
	debug('download called with arguments: %o',arguments);
	if (!nobanner && !wantVersion) { util.waitMessage('Finding latest version ...'); }
	if (!nobanner && wantVersion) { util.waitMessage('Finding version '+wantVersion+' ...'); }
	retryAttempts = retryAttempts || 1;
	var bar;
	pendingRequest = util.request(location, function (err,res,req) {
		if (err) {
			debug('error from download was: %o',err);
			if (err.code === 'ECONNREFUSED' || err.code === 'ECONNRESET') {
				pendingRequest = null;
				util.resetLine();
				if (retryAttempts > MAX_RETRIES) {
					return callback(errorlib.createError('com.appcelerator.install.download.server.unavailable'));
				}
				// retry again
				debug('retrying request again, count=%d, delay=%d',retryAttempts,500*retryAttempts);
				return setTimeout(function() {
					download(quiet, force, wantVersion, tmpfile, stream, location, callback, true, retryAttempts+1);
				},500*retryAttempts);
			}
			else if (err.name === 'AppCError') {
				return callback(err);
			}
			return callback(errorlib.createError('com.appcelerator.install.download.server.response.error',err.message));
		}
		debug('response status code was: %d',res.statusCode);
		// console.log(res);
		if (res.statusCode===301 || res.statusCode===302) {
			// handle redirect
			location = res.headers.location;
			pendingRequest = null;
			util.resetLine();
			return download(quiet, force, wantVersion, tmpfile, stream, location, callback, nobanner, retryAttempts);
		}
		else if (res.statusCode===404) {
			pendingRequest = null;
			return callback(errorlib.createError('com.appcelerator.install.download.version.specified.incorrect',wantVersion));
		}
		else if (res.statusCode===200) {
			debug('response headers: %j',res.headers);

			var version = res.headers['x-appc-version'] || res.headers['x-amz-meta-version'],
				shasum = res.headers['x-appc-shasum'] || res.headers['x-amz-meta-shasum'],
				hash = require('crypto').createHash('sha1');

			hash.setEncoding('hex');

			debug('download version: %s, shasum: %s',version,shasum);

			if (!nobanner && !wantVersion) { util.okMessage(chalk.green(version)); }
			if (!nobanner && wantVersion) { util.okMessage(); }

			// check to see if we have it already installed and if we do, just continue
			if (!force && version) {
				var bin = util.getInstallBinary(null, version);
				if (bin) {
					return callback(null, null, version, bin);
				}
			}

			var total = parseInt(res.headers['content-length'], 10);
			debug('download content-length: %d',total);

			if (!total) {
				return callback(errorlib.createError('com.appcelerator.install.download.invalid.content.length'));
			}

			bar = (!nobanner && process.stdout.isTTY && !process.env.TRAVIS) &&
				new ProgressBar('Downloading [:bar] :percent :etas', {
					complete: util.isWindows() ? '█' : chalk.green('▤'),
					incomplete: ' ',
					width: Math.max(40, Math.round(process.stdout.columns/2)),
					total: total,
					clear: true,
					stream: process.stdout
			});
			var count = 0,
				tickCount = 0,
				tickDiff = total*0.01;

			util.stopSpinner();

			if (!bar) {
				util.waitMessage('Downloading ...');
			}

			res.on('data', function (chunk) {
				if (chunk.length) {
					if (bar) {
						tickCount += chunk.length;
						if (tickCount > tickDiff) {
							bar.tick(tickCount);
							tickCount = 0;
						}
					}
					stream.write(chunk);
					hash.update(chunk);
					count+=chunk.length;
				}
			});

			res.on('error', function(err){
				debug('download error %o',err);
				try {
					stream.end();
				}
				catch (E) {
				}
				pendingRequest = null;
				callback(errorlib.createError('com.appcelerator.install.download.server.stream.error',err.message));
			});

			res.on('end', function () {
				debug('download end');
				if (bar) { bar.tick(tickCount); }
				stream.end();
				pendingRequest = null;
				// check to make sure we downloaded all the bytes we needed too
				// if not, this means the download failed and we should attempt to re-start it
				if (count !== total) {
					debug('download max retry');
					if (bar) { bar.terminate(); util.resetLine(); }
					stream.end();
					if (retryAttempts >= MAX_RETRIES) {
						return callback(errorlib.createError('com.appcelerator.install.download.failed.retries.max',retryAttempts));
					}
					// re-open stream
					stream = fs.createWriteStream(tmpfile);
					var delay = retryAttempts * 2000;
					// download failed, we should re-start
					return setTimeout(function(){
						download(force, wantVersion, tmpfile, stream, location, callback, true, retryAttempts+1);
					},delay);
				}
				hash.end();
				var checkshasum = hash.read();
				debug('download checkshasum: %s',checkshasum);
				// our downloaded file checksum should match what we uploaded, if not, this is a security violation
				if (checkshasum!==shasum) {
					return callback(errorlib.createError('com.appcelerator.install.download.failed.checksum',shasum,checkshasum));
				}
				else {
					if (!quiet) { 
						util.infoMessage('Validating security checksum '+chalk.green(util.isWindows()?'OK':'✓'));
					}
				}
				process.nextTick(function(){
					callback(null, tmpfile, version);
				});
			});
		}
		else if (/^(408|500|503)$/.test(String(res.statusCode))) {
			// some sort of error on the server, let's re-try again ...
			// 408 is a server timeout
			// 500 is a server error
			// 503 is a server unavailable. this could be a deployment in progress
			debug('download server error ... will retry');
			stream.end();
			if (bar) { util.resetLine(); }
			pendingRequest = null;
			if (retryAttempts >= MAX_RETRIES) {
				debug('download server error ... maxed out after %d attempts',retryAttempts);
				return callback(errorlib.createError('com.appcelerator.install.download.server.unavailable'));
			}
			var delay = retryAttempts * 500;
			debug('download server error ... retry delay %d ms',delay);
			stream = fs.createWriteStream(tmpfile);
			return setTimeout(function() {
				download(quiet, force, wantVersion, tmpfile, stream, location, callback, true, retryAttempts+1);
			},delay);
		}
		else {
			debug('download server unexpected error %d',res.statusCode);
			stream.end();
			if (bar) { util.resetLine(); }
			pendingRequest = null;
			return callback(errorlib.createError('com.appcelerator.install.download.server.response.unexpected',res.statusCode));
		}
	});
}

exports.start = function(quiet, banner, force, location, wantVersion, callback) {
	var tmpfile = path.join(tmpdir, 'appc-'+(+new Date())+'.tar.gz'),
		stream = fs.createWriteStream(tmpfile),
		exitFn,
		sigintFn,
		pendingAbort,
		createCleanup = function createCleanup(name) {
			return function(exit) {
				if (pendingRequest) {
					try {
						// abort the pending HTTP request so it will
						// close the server socket
						pendingRequest.abort();
					}
					catch (E) {
					}
					pendingRequest = null;
				}
				try {
					if (fs.existSync(tmpfile)) {
						fs.unlinkSync(tmpfile);
					}
				}
				catch (E) {
				}
				if (name==='SIGINT') {
					pendingAbort = true;
					process.removeListener('SIGINT',sigintFn);
					util.abortMessage('Download');
				}
				else if (name==='exit') {
					process.removeListener('exit',exitFn);
					if (!pendingAbort) {
						process.exit(exit);
					}
				}
				else {
					process.removeListener('exit',exitFn);
					process.removeListener('SIGINT',sigintFn);
				}
			};
		};

	// make sure we remove the file on shutdown
	process.on('exit', (exitFn=createCleanup('exit')));
	process.on('SIGINT', (sigintFn=createCleanup('SIGINT')));

	// default banner is on for process downloads unless quiet or no banner
	quiet = quiet===undefined ? false : quiet;
	banner = (banner===undefined ? true : banner) && !(quiet);

	debug('download start, quiet %d, banner %d',quiet,banner);

	// run the download
	download(quiet, force, wantVersion, tmpfile, stream, location, function(){
		// remove clean listeners
		createCleanup('done')();
		// carry on... 🙏
		return callback.apply(null,arguments);
	},!banner);
};