Automatically sign and align apk built with Ionic v3

sign_apk.js

#!/usr/bin/env node

// ## Automatically sign and align apk ##
// Just run this script `$ node sign_apk.js`

const CONFIG_FILE_NAME = 'sign-apk.json';
const configFileStruct = {
	"keystorePath": "relative/path/to/file.keystore",
	"zipalignPath": "C:/Program Files (x86)/Android/android-sdk/build-tools/26.0.2/zipalign",
	"apkPath": "C:/your-ionic-project-root/platforms/android/build/outputs/apk/android-release-unsigned.apk",
	"alias": "keystore_alias",
	"password": "keystore_password",
	"output": "C:/your-ionic-project-root/platforms/android/build/outputs/apk/your_apk.apk"
}

// Load configuration
let configFile = {};
const configFilePath = `${require.main.paths[0].replace('node_modules', '')}\\${CONFIG_FILE_NAME}`;
try {
	configFile = require(configFilePath)
} catch (e) {
	const json = JSON.stringify(configFileStruct, null, 2);
	const msg = `The file '${configFilePath}' file has not been found.\nPlease create it with the following structure:\n\n${json}\n`;
	console.error(e);
	throw msg;
}
const KEYSTORE_PATH = configFile.keystorePath;
const ZIPALIGN_PATH = configFile.zipalignPath;
const APK_PATH = configFile.apkPath;
const ALIAS = configFile.alias;
const PWD = configFile.password;
const OUTPUT_PATH = configFile.output;
// ===================================

startJob();

function signAndAlignApk(output) {
	const { spawn } = require('child_process');

	let command = 'jarsigner';
	let args = ['-verbose', '-sigalg', 'SHA1withRSA', '-digestalg', 'SHA1', '-keystore', KEYSTORE_PATH, APK_PATH, ALIAS];

	console.log('Sign apk: %s', 'jarsigner ' + args.join(' '));
	const p = APK_PATH.split('/');
	p.pop();
	let child = spawn(command, args);

	// Enter password
	child.stdin.setEncoding('utf-8');
	child.stdin.write(PWD + "\n");
	child.stdin.end();

	child.stdout.on('data', (data) => {
		console.log(`SignApk stdout: ${data}`);
	});

	child.stderr.on('data', (data) => {
		console.log(`SignApk stderr: ${data}`);
	});

	child.on('close', (code) => {
		console.log(`Apk Signed`);
		alignApk(output);
	});
}

function alignApk(output) {
	const { exec } = require('child_process');
	let command = '"' + ZIPALIGN_PATH + '" -v 4 "' + APK_PATH + '" "' + output + '"';
	console.log("Align apk: %s\n", command);

	exec(command,
		(err, stdout, stderr) => {
			if (err) {
				console.error(err);
				return;
			}
			console.log("stdout");
			console.log("Apk signed and aligned!");

		});
}

function getVersion(callback) {
	console.log('Get version:');

	try {
		var fs = require('fs');
		var xml2js = require('xml2js');

		// Read config.xml
		fs.readFile('config.xml', 'utf8', function (err, data) {
			if (err) {
				console.log(err);
				callback(null);
				return;
			}

			// Get XML
			var xml = data;

			// Parse XML to JS Obj
			xml2js.parseString(xml, function (err, result) {
				if (err) {
					console.log(err);
					callback(null);
					return;
				}

				// Get version inside widget attributes or create it
				var obj = result;
				var version = obj['widget']['$']['version'];
				console.log(version);
				callback(version);
				return;
			})
		})
	} catch (e) {
		console.warn("Couldn't read version from config.xml file. Make sure you've node installed 'fs' and 'xml2js' if you wish to also add version number to your ouput filename ");
		callback(null);
	}
}

function startJob() {
	getVersion(v => {
		let output = OUTPUT_PATH;
		if (v) output = output.replace('.apk', '') + '_r' + v + '.apk';
		signAndAlignApk(output);
	});
}