Merge pull request #14 from smithclay/cleanup-0.1.1

Use standard logging library, reuse session for performance

Author: smithclay

README.md

@@ -1,6 +1,8 @@
 ## lambdium
 ### headless chrome + selenium webdriver in AWS Lambda
 
+**Lambdium allows you to run a Selenium Webdriver script written in Javascript inside of an AWS Lambda function bundled with [Headless Chromium](https://developers.google.com/web/updates/2017/04/headless-chrome).**
+
 *This project is now published on the [AWS Serverless Application Repository](https://serverlessrepo.aws.amazon.com), allowing you to install it in your AWS account with one click. Install in your AWS account [here](https://serverlessrepo.aws.amazon.com/#/applications/arn:aws:serverlessrepo:us-east-1:156280089524:applications~lambdium).* Quickstart instructions are in the [`README-SAR.md` file](https://github.com/smithclay/lambdium/blob/master/README-SAR.md).
 
 This uses the binaries from the [serverless-chrome](https://github.com/adieuadieu/serverless-chrome) project to prototype running headless chromium with `selenium-webdriver` in AWS Lambda. I've also bundled the chromedriver binary so the browser can be interacted with using the [Webdriver Protocol](https://www.w3.org/TR/webdriver/).
@@ -13,61 +15,63 @@ The function interacts with [headless Chromium](https://chromium.googlesource.co
 
 Since this Lambda function is written using node.js, you can run almost any script written for [selenium-webdriver](https://www.npmjs.com/package/selenium-webdriver). Example scripts can be found in the `examples` directory.
 
-#### Requirements
+#### Requirements and Setup
 
 * An AWS Account
 * The [AWS SAM Local](https://github.com/awslabs/aws-sam-local) tool for running functions locally with the [Serverless Application Model](https://github.com/awslabs/serverless-application-model) (see: `template.yaml`)
 * node.js + npm
 * `modclean` npm modules for reducing function size (optional)
 * Bash
 
-#### Fetching dependencies
+_Note:_ If you don't need to build, customize, or run this locally, you can deploy it directly from a [template on the AWS Serverless Application repository](https://serverlessrepo.aws.amazon.com/#/applications/arn:aws:serverlessrepo:us-east-1:156280089524:applications~lambdium) and skip all of the below steps. 
+
+#### 1. Fetching dependencies
 
 The headless chromium binary is too large for Github, you need to fetch it using a script bundled in this repository. [Marco Lüthy](https://github.com/adieuadieu) has an excellent post on Medium about how he built chromium for for AWS Lambda [here](https://medium.com/@marco.luethy/running-headless-chrome-on-aws-lambda-fa82ad33a9eb). 
 
 ```sh
     $ ./scripts/fetch-dependencies.sh
 ```
 
-#### Running locally with SAM Local
+##### 2. Cleaning up the `node_modules` directory to reduce function size
 
-SAM Local can run this function on your computer inside a Docker container that acts like AWS Lambda. To run the function with an example event trigger that uses selenium to use headless chromium to visit `google.com`, run this:
+It's a good idea to clean the `node_modules` directory before packaging to make the function size significantly smaller (making the function run faster!). You can do this using the `modclean` package:
+
+To install it:
 
 ```sh
-    $ sam local invoke Lambdium -e event.json
+    $ npm i -g modclean
 ```
 
-### Deploying
-
-#### Creating a bucket for the function deployment
-
-This will create a file called `packaged.yaml` you can use with Cloudformation to deploy the function.
-
-You need to have an S3 bucket configured on your AWS account to upload the packed function files. For example:
+Then, run: 
 
 ```sh
-    $ export LAMBDA_BUCKET_NAME=lambdium-upload-bucket
+    $ modclean --patterns="default:*"
 ```
 
-##### Reducing function size for performance (and faster uploads!)
+Follow the prompts and choose 'Y' to remove extraneous files from `node_modules`.
 
-It's a good idea to clean the `node_modules` directory before packaging to make the function size significantly smaller (making the function run faster!). You can do this using the `modclean` package:
+#### 3. Running locally with SAM Local
 
-To install it:
+SAM Local can run this function on your computer inside a Docker container that acts like AWS Lambda. To run the function with an example event trigger that uses selenium to use headless chromium to visit `google.com`, run this:
 
 ```sh
-    $ npm i -g modclean
+    $ sam local invoke Lambdium -e event.json
 ```
 
-Then, run: 
+### Deploying
+
+#### Creating a S3 bucket for the function deployment
+
+This will create a file called `packaged.yaml` you can use with Cloudformation to deploy the function.
+
+You need to have an S3 bucket configured on your AWS account to upload the packed function files. For example:
 
 ```sh
-    $ modclean --patterns="default:*"
+    $ export LAMBDA_BUCKET_NAME=lambdium-upload-bucket
 ```
 
-Follow the prompts and choose 'Y' to remove extraneous files from `node_modules`.
-
-##### Packaging the function for Cloudformation using SAM
+#### Packaging the function for Cloudformation using SAM
 
 ```sh
     $ sam package --template-file template.yaml --s3-bucket $LAMBDA_BUCKET_NAME --output-template-file packaged.yaml
@@ -83,7 +87,7 @@ This will create the function using Cloudformation after packaging it is complet
 
 If set, the optional `DEBUG_ENV` environment variable will log additional information to Cloudwatch.
 
-## Invoking the function
+### Running the function
 
 Post-deploy, you can have lambda run a Webdriver script. There's an example of a selenium-webdriver simple script in the `examples/` directory that the Lambda function can now run.
 

examples/visitgoogle.js

@@ -11,5 +11,5 @@ $browser.findElement($driver.By.name('btnK')).click();
 $browser.wait($driver.until.titleIs('Google'), 1000);
 $browser.getTitle().then(function(title) {
     console.log("title is: " + title);
+    console.log('Finished running script!');
 });
-console.log('Finished running script!');

index.js

@@ -4,26 +4,35 @@ const fs = require('fs');
 
 const chromium = require('./lib/chromium');
 const sandbox = require('./lib/sandbox');
-const { log } = require('./lib/helpers');
+const log = require('lambda-log');
 
-console.log('Loading function');
+log.info('Loading function');
+
+// Create new reusable session (spawns chromium and webdriver)
+if (!process.env.CLEAN_SESSIONS) {
+  $browser = chromium.createSession();
+}
 
 exports.handler = (event, context, callback) => {
   context.callbackWaitsForEmptyEventLoop = false;
 
-  if (process.env.CLEAR_TMP) {
-    log('attempting to clear /tmp directory')
-    log(child.execSync('rm -rf /tmp/core*').toString());
+  if (process.env.CLEAN_SESSIONS) {
+    log.info('attempting to clear /tmp directory')
+    log.info(child.execSync('rm -rf /tmp/core*').toString());
+  }
+
+  if (process.env.DEBUG_ENV || process.env.SAM_LOCAL) {
+    log.config.debug = true;
+    log.config.dev = true;
   }
 
-  if (process.env.DEBUG_ENV) {
-    //log(child.execSync('set').toString());
-    log(child.execSync('pwd').toString());
-    log(child.execSync('ls -lhtra .').toString());
-    log(child.execSync('ls -lhtra /tmp').toString());
+  if (process.env.LOG_DEBUG) {
+    log.debug(child.execSync('pwd').toString());
+    log.debug(child.execSync('ls -lhtra .').toString());
+    log.debug(child.execSync('ls -lhtra /tmp').toString());  
   }
 
-  log('Received event:', JSON.stringify(event, null, 2));
+  log.info(`Received event: ${JSON.stringify(event, null, 2)}`);
 
   // Read input
   const inputParam = event.Base64Script || process.env.BASE64_SCRIPT;
@@ -32,17 +41,18 @@ exports.handler = (event, context, callback) => {
   }
 
   const inputBuffer = Buffer.from(inputParam, 'base64').toString('utf8');
-  if (process.env.DEBUG_ENV) {
-    log(`Executing "${inputBuffer}"`);
+  log.debug(`Executing script "${inputBuffer}"`);
+
+  // Creates a new session on each event (instead of reusing for performance benefits)
+  if (process.env.CLEAN_SESSIONS) {
+    $browser = chromium.createSession();
   }
 
-  // Start selenium webdriver session
-  $browser = chromium.createSession();
   sandbox.executeScript(inputBuffer, $browser, webdriver, function(err) {
-    if (process.env.DEBUG_ENV) {
-      log(child.execSync('ps aux').toString());
+    if (process.env.LOG_DEBUG) {
+      log.debug(child.execSync('ps aux').toString());
+      log.debug(child.execSync('cat /tmp/chromedriver.log').toString())
     }
-
     if (err) {
       callback(err, null);
     }

lib/chromium.js

@@ -1,5 +1,4 @@
 const child = require('child_process');
-const { log } = require('./helpers');
 const os = require('os');
 const path = require('path');
 const chrome = require('selenium-webdriver/chrome');
@@ -44,9 +43,15 @@ const defaultChromeFlags = [
 const HEADLESS_CHROME_PATH = 'bin/headless-chromium';
 const CHROMEDRIVER_PATH = '/var/task/bin/chromedriver';
 exports.createSession = function() {
-  const service = new chrome.ServiceBuilder(CHROMEDRIVER_PATH)
-    .enableVerboseLogging()
-    .build();
+  var service;
+  if (process.env.LOG_DEBUG || process.env.SAM_LOCAL) {
+    service = new chrome.ServiceBuilder(CHROMEDRIVER_PATH)
+      .loggingTo('/tmp/chromedriver.log')
+      .build();
+  } else {
+    service = new chrome.ServiceBuilder(CHROMEDRIVER_PATH)
+      .build();
+  }
 
   const options = new chrome.Options();
 
@@ -60,16 +65,3 @@ exports.createSession = function() {
   return chrome.Driver.createSession(options, service);
 }
 
-const spawnProcess = function(localPath, flags) {
-  const opts = {
-      cwd: os.tmpdir(),
-      shell: true,
-      detached: true,
-  };
-
-  const proc = child.spawn(path.join(process.env.LAMBDA_TASK_ROOT, localPath), 
-    flags,
-    opts
-  );
-  return proc; 
-};

lib/helpers.js

@@ -1,4 +1,5 @@
 const vm = require('vm');
+const log = require('lambda-log');
 
 exports.executeScript = function(scriptText, browser, driver, cb) {
   // Create Sandbox VM
@@ -14,7 +15,7 @@ exports.executeScript = function(scriptText, browser, driver, cb) {
   try {
     script.runInContext(scriptContext);
   } catch (e) {
-    console.log('[script error]', e);
+    log.error(`[script error] ${e}`);
     return cb(e, null);
   } 
 
@@ -27,8 +28,19 @@ exports.executeScript = function(scriptText, browser, driver, cb) {
       }
   });
   */
-
-  $browser.quit().then(function() {
-    cb(null);
-  });
-}
+  // https://github.com/GoogleChrome/puppeteer/issues/1825#issuecomment-372241101
+  // Reuse existing session, likely some edge cases around this...
+  if (process.env.CLEAN_SESSIONS) {
+    $browser.quit().then(function() {
+      cb(null);
+    });
+  } else {
+    browser.manage().deleteAllCookies().then(function() {
+      return $browser.get('about:blank').then(function() {
+        cb(null);
+      }).catch(function(err) {
+        cb(err);
+      });
+    });
+  }
+}

lib/sandbox.js

@@ -1,6 +1,6 @@
 {
   "name": "lambdium",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "headless chromium in lambda prototype",
   "main": "index.js",
   "scripts": {
@@ -9,6 +9,7 @@
   "author": "Clay Smith",
   "license": "ISC",
   "dependencies": {
+    "lambda-log": "^1.3.0",
     "selenium-webdriver": "^3.6.0"
   }
 }

package-lock.json

@@ -9,10 +9,9 @@ Resources:
       Runtime: nodejs6.10
       FunctionName: lambdium
       Description: headless chromium running selenium
-      MemorySize: 1024
-      Timeout: 10
+      MemorySize: 1156
+      Timeout: 20
       Environment:
         Variables:
-          DEBUG_ENV: "true"
           CLEAR_TMP: "true"
       CodeUri: .