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Example Web Server

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Example Web Server

Example Web Server

apify/example-web-server
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This example demonstrates how to use web server in actor as communication channel with outer world. Read more at Apify docs https://docs.apify.com/actors/running#container-web-server

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Dockerfile

1# This is a template for a Dockerfile used to run acts in Actor system.
2# The base image name below is set during the act build, based on user settings.
3# IMPORTANT: The base image must set a correct working directory, such as /usr/src/app or /home/user
4FROM apify/actor-node-chrome:v0.21.10
5
6# Second, copy just package.json and package-lock.json since it should be
7# the only file that affects "npm install" in the next step, to speed up the build
8COPY package*.json ./
9
10# Install NPM packages, skip optional and development dependencies to
11# keep the image small. Avoid logging too much and print the dependency
12# tree for debugging
13RUN npm --quiet set progress=false \
14 && npm install --only=prod --no-optional \
15 && echo "Installed NPM packages:" \
16 && (npm list --all || true) \
17 && echo "Node.js version:" \
18 && node --version \
19 && echo "NPM version:" \
20 && npm --version
21
22# Copy source code to container
23# Do this in the last step, to have fast build if only the source code changed
24COPY --chown=myuser:myuser . ./
25
26# NOTE: The CMD is already defined by the base image.
27# Uncomment this for local node inspector debugging:
28# CMD [ "node", "--inspect=0.0.0.0:9229", "main.js" ]

package.json

1{
2    "name": "apify-project",
3    "version": "0.0.1",
4    "description": "",
5    "author": "It's not you it's me",
6    "license": "ISC",
7    "dependencies": {
8        "apify": "0.21.10",
9        "express": "latest",
10        "body-parser": "latest"
11    },
12    "scripts": {
13        "start": "node main.js"
14    }
15}

main.js

1const Apify = require('apify');
2const express = require('express')
3const bodyParser = require('body-parser');
4
5// Create ExpressJS app and configure body parsers that will allow us to receive form submissions.
6const app = express()
7app.use(bodyParser.json());
8app.use(bodyParser.urlencoded({ extended: true }));
9
10//  Now we need to read following environment variables: 
11// - APIFY_CONTAINER_PORT  contains a port number where we must start server 
12// - APIFY_CONTAINER_URL  contains a URL under which we can access the container
13// - APIFY_DEFAULT_KEY_VALUE_STORE_ID is simply ID of default key-value store of this 
14//   actor where we can store screenshots
15const {
16    APIFY_CONTAINER_PORT,
17    APIFY_CONTAINER_URL,
18    APIFY_DEFAULT_KEY_VALUE_STORE_ID,
19} = process.env;
20
21// Create an array of the processed URLs where n-th URL has its screenshot stored under the 
22// key [n].jpg in key-value store:
23const processedUrls = [];
24
25// Root path displays a HTML form to submit new URL and thumbnails of processed URLs:
26app.get('/', (req, res) => {
27    let listItems = '';
28
29    // For each of the processed
30    processedUrls.forEach((url, index) => {
31        const imageUrl = `https://api.apify.com/v2/key-value-stores/${APIFY_DEFAULT_KEY_VALUE_STORE_ID}/records/${index}.jpg`;
32
33        listItems += `<li>
34    <a href="${imageUrl}" target="_blank">
35        <img src="${imageUrl}" width="300px" />
36        <br />
37        ${url}
38    </a>
39</li>`;
40    });
41
42    const pageHtml = `
43<html>
44    <head><title>Example</title></head>
45    <body>
46        <form method="POST" action="${APIFY_CONTAINER_URL}/add-url">
47            URL: <input type="text" name="url" placeholder="http://example.com" />
48            <input type="submit" value="Add" />
49            <hr />
50            <ul>${listItems}</ul>
51        </form>
52    </body>
53</html>`;
54
55    res.send(pageHtml);
56});
57
58// POST route allowing us to submit new URLs. After URL is processed
59// it redirects user back to root path.
60app.post('/add-url', async (req, res) => {
61    const { url } = req.body;
62    console.log(`Got new URL: ${url}`);
63
64    // Start chrome browser and open new page ...
65    const browser = await Apify.launchPuppeteer();
66    const page = await browser.newPage();
67
68    // ... go to our URL and grab a screenshot ...
69    await page.goto(url);
70    const screenshot = await page.screenshot({ type: 'jpeg' });
71
72    // ... close browser ...
73    await page.close();
74    await browser.close(); 
75
76    // ... save sreenshot to key-value store and add URL to processedUrls.
77    await Apify.setValue(`${processedUrls.length}.jpg`, screenshot, { contentType: 'image/jpeg' });
78    processedUrls.push(url);
79
80    res.redirect('/');
81});
82
83// Start the webserver.
84app.listen(APIFY_CONTAINER_PORT, () => {
85    console.log(`Application is listening at URL ${APIFY_CONTAINER_URL}.`);
86});
Developer
Maintained by Apify
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  • 1 monthly user
  • 4 stars
  • 37 days response time
  • Created in Jul 2018
  • Modified 5 months ago