keep browser running

Author: sambaiz

README.md

@@ -12,7 +12,12 @@ By executing `SLOWMO_MS=250 npm run local`, you can check the operation while ac
 
 ## Packaging & Deploy
 
-Lambda's memory is set to 384 MB or more.
+Lambda's memory needs to be set to at least 384 MB, but the more memory, the better the performance of any operations.
+
+```
+512MB -> goto(youtube): 6.481s
+1536MB(Max) -> goto(youtube): 2.154s
+```
 
 ### chrome in package (recommended)
 
@@ -30,6 +35,8 @@ Run `npm run package-nochrome`, deploy the package.zip, and set following env va
 
 ## Build Headless-Chrome (optional)
 
+This kit includes Chrome built by myself because official build Chrome installed by Puppeteer has problems about running on Lambda (missing shared library etc.).
+
 If you want to use latest chrome, run chrome/buildChrome.sh on EC2 having at least 16GB memory and 30GB volume. 
 See also [serverless-chrome](https://github.com/adieuadieu/serverless-chrome/blob/master/chrome/README.md).
 Once you build it, link to `headless_shell.tar.gz` in `chrome` dir.

src/index.js

@@ -1,28 +1,19 @@
-const puppeteer = require('puppeteer');
-const config = require('./starter-kit/config');
-const util = require('./starter-kit/util');
+const setup = require('./starter-kit/setup');
 
 exports.handler = async (event, context, callback) => {
-  exports.run({
-    headless: true,
-    executablePath: await util.setupChrome(),
-    args: config.launchOptionForLambda,
-    dumpio: !!util.DEBUG,
-  }).then(
+  // For keeping the browser launch
+  context.callbackWaitsForEmptyEventLoop = false;
+  const browser = await setup.getBrowser();
+  exports.run(browser).then(
     (result) => callback(null, result)
   ).catch(
     (err) => callback(err)
   );
 };
 
-exports.run = async (launchOption) => {
-  const browser = await puppeteer.launch(launchOption);
-
-  util.debugLog(`Chrome launched, version ${await browser.version()}`);
-
+exports.run = async (browser) => {
   const page = await browser.newPage();
   await page.goto('https://www.google.co.jp');
-  browser.close();
-
+  await page.close();
   return 'done';
 };

src/starter-kit/config.js

@@ -1,8 +1,32 @@
-exports.launchOptionForLambda = [
+const path = require('path');
+
+const launchOptionForLambda = [
     // error when launch(); No usable sandbox! Update your kernel
     '--no-sandbox',
     // error when launch(); Failed to load libosmesa.so
     '--disable-gpu',
     // freeze when newPage()
     '--single-process',
 ];
+
+const localChromePath = path.join('headless_shell.tar.gz');
+const remoteChromeS3Bucket = process.env.CHROME_BUCKET;
+const remoteChromeS3Key = process.env.CHROME_KEY || 'headless_shell.tar.gz';
+
+const setupChromePath = path.join(path.sep, 'tmp');
+const executablePath = path.join(
+    setupChromePath,
+    'headless_shell'
+);
+
+const DEBUG = process.env.DEBUG;
+
+module.exports = {
+    launchOptionForLambda,
+    localChromePath,
+    remoteChromeS3Bucket,
+    remoteChromeS3Key,
+    setupChromePath,
+    executablePath,
+    DEBUG,
+};

src/starter-kit/local.js

@@ -1,13 +1,17 @@
+process.env.LOCAL = 1;
 const index = require('../index');
-const util = require('./util');
+const config = require('./config');
+const puppeteer = require('puppeteer');
 
-index.run({
-    headless: false,
-    slowMo: process.env.SLOWMO_MS,
-    dumpio: !!util.DEBUG,
-    // use chrome installed by puppeteer
-}).then(
-    (result) => console.log(result)
-).catch(
-    (err) => console.error(err)
-);
+(async () => {
+    const browser = await puppeteer.launch({
+        headless: false,
+        slowMo: process.env.SLOWMO_MS,
+        dumpio: !!config.DEBUG,
+        // use chrome installed by puppeteer
+    });
+    await index.run(browser)
+    .then((result) => console.log(result))
+    .catch((err) => console.error(err));
+    await browser.close();
+})();

src/starter-kit/util.js renamed to src/starter-kit/setup.js

@@ -1,57 +1,62 @@
-const CHROME_BUCKET = process.env.CHROME_BUCKET;
-const CHROME_KEY = process.env.CHROME_KEY || 'headless_shell.tar.gz';
 const aws = require('aws-sdk');
 const s3 = new aws.S3({apiVersion: '2006-03-01'});
 const fs = require('fs');
 const tar = require('tar');
-const path = require('path');
+const puppeteer = require('puppeteer');
+const config = require('./config');
 
-const localChromePath = path.join('headless_shell.tar.gz');
-const setupChromePath = path.join(path.sep, 'tmp');
-
-exports.DEBUG = process.env.DEBUG;
+exports.getBrowser = (() => {
+  let browser;
+  return async () => {
+    if (typeof browser === 'undefined') {
+      await setupChrome();
+      browser = await puppeteer.launch({
+        headless: true,
+        executablePath: config.executablePath,
+        args: config.launchOptionForLambda,
+        dumpio: !!exports.DEBUG,
+      });
+      debugLog(`launch done: ${await browser.version()}`);
+    }
+    return browser;
+  };
+})();
 
-exports.setupChrome = async () => {
+const setupChrome = async () => {
   if (!await existsExecutableChrome()) {
     if (await existsLocalChrome()) {
-      exports.debugLog('setup local chrome');
+      debugLog('setup local chrome');
       await setupLocalChrome();
     } else {
-      exports.debugLog('setup s3 chrome');
+      debugLog('setup s3 chrome');
       await setupS3Chrome();
     }
-    exports.debugLog('setup done');
+    debugLog('setup done');
   }
-  return executablePath;
 };
 
-const executablePath = path.join(
-  setupChromePath,
-  'headless_shell'
-);
-
 const existsLocalChrome = () => {
   return new Promise((resolve, reject) => {
-    fs.exists(localChromePath, (exists) => {
+    fs.exists(config.localChromePath, (exists) => {
       resolve(exists);
     });
   });
 };
 
 const existsExecutableChrome = () => {
   return new Promise((resolve, reject) => {
-    fs.exists(executablePath, (exists) => {
+    fs.exists(config.executablePath, (exists) => {
       resolve(exists);
     });
   });
 };
 
 const setupLocalChrome = () => {
     return new Promise((resolve, reject) => {
-      fs.createReadStream(localChromePath)
+      fs.createReadStream(config.localChromePath)
       .on('error', (err) => reject(err))
       .pipe(tar.x({
-        C: setupChromePath,
+        C: config.setupChromePath,
       }))
       .on('error', (err) => reject(err))
       .on('end', () => resolve());
@@ -60,18 +65,21 @@ const setupLocalChrome = () => {
 
 const setupS3Chrome = () => {
     return new Promise((resolve, reject) => {
-      const params = {Bucket: CHROME_BUCKET, Key: CHROME_KEY};
+      const params = {
+        Bucket: config.remoteChromeS3Bucket,
+        Key: config.remoteChromeS3Key,
+      };
       s3.getObject(params)
       .createReadStream()
       .on('error', (err) => reject(err))
       .pipe(tar.x({
-        C: setupChromePath,
+        C: config.setupChromePath,
       }))
       .on('error', (err) => reject(err))
       .on('end', () => resolve());
     });
 };
 
-exports.debugLog = (log) => {
-    if (exports.DEBUG) console.log(log);
+const debugLog = (log) => {
+    if (config.DEBUG) console.log(log);
 };