GCF: Headless Chrome sample (#705)

* Headless Chrome sample

* Remove test script
Function emulator does not support node8...

* update puppeteer

* await browser close

* Do not instantiate browser at each requests

* use more descriptive tag

* use better package name

Author: steren

functions/headless-chrome/index.js

@@ -0,0 +1,46 @@
+/**
+ * Copyright 2018, Google, Inc.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+
+// [START functions_headless_chrome]
+const puppeteer = require('puppeteer');
+
+let page;
+
+async function getBrowserPage () {
+  // [START start_browser]
+  const browser = await puppeteer.launch({args: ['--no-sandbox']});
+  // [END start_browser]
+  return browser.newPage();
+}
+
+exports.screenshot = async (req, res) => {
+  const url = req.query.url;
+
+  if (!url) {
+    return res.send('Please provide URL as GET parameter, for example: <a href="?url=https://example.com">?url=https://example.com</a>');
+  }
+
+  if (!page) {
+    page = await getBrowserPage();
+  }
+
+  await page.goto(url);
+  const imageBuffer = await page.screenshot();
+  res.set('Content-Type', 'image/png');
+  res.send(imageBuffer);
+};
+// [END functions_headless_chrome]

functions/headless-chrome/package.json

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+{
+  "name": "nodejs-docs-samples-functions-headless-chrome",
+  "version": "0.0.1",
+  "private": true,
+  "license": "Apache-2.0",
+  "author": "Google Inc.",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git"
+  },
+  "engines": {
+    "node": ">=8"
+  },
+  "scripts": {
+    "lint": "repo-tools lint",
+    "pretest": "npm run lint",
+    "e2e-test": "export FUNCTIONS_CMD='gcloud beta functions' && sh test/updateFunctions.sh && BASE_URL=\"https://$GCF_REGION-$GCLOUD_PROJECT.cloudfunctions.net/\" ava -T 20s --verbose test/*.test.js"
+  },
+  "dependencies": {
+    "puppeteer": "^1.6.2"
+  },
+  "devDependencies": {
+    "@google-cloud/nodejs-repo-tools": "^2.2.5",
+    "ava": "0.25.0",
+    "supertest": "^3.0.0"
+  },
+  "cloud-repo-tools": {
+    "requiresKeyFile": true,
+    "requiresProjectId": true,
+    "requiredEnvVars": [
+      "BASE_URL",
+      "GCF_REGION",
+      "FUNCTIONS_CMD"
+    ]
+  }
+}

functions/headless-chrome/test/index.test.js

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+/**
+ * Copyright 2017, Google, Inc.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const test = require(`ava`);
+const tools = require(`@google-cloud/nodejs-repo-tools`);
+const supertest = require(`supertest`);
+
+const BASE_URL = process.env.BASE_URL;
+
+test.before(`Must specify BASE_URL`, t => {
+  t.truthy(BASE_URL);
+});
+
+test.before(tools.checkCredentials);
+
+test.cb(`screenshot: should return a screenshot`, (t) => {
+  supertest(BASE_URL)
+    .get(`/screenshot?url=https://example.com`)
+    .send()
+    .expect(200)
+    .expect(response => {
+      t.is(response.type, `image/png`);
+      t.true(response.body instanceof Buffer);
+      t.true(response.body.length > 0);
+    })
+    .end(t.end);
+});

functions/headless-chrome/test/updateFunctions.sh

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+#!/bin/bash
+# Shell script to emulate/deploy all Cloud Functions in the file
+
+${FUNCTIONS_CMD} deploy screenshot --trigger-http --runtime nodejs8 --memory 1024MB