Initial commit

.gitignore

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+
+# Created by https://www.gitignore.io/api/node
+
+### Node ###
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Typescript v1 declaration files
+typings/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+
+
+# End of https://www.gitignore.io/api/node

crawl

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+#!/usr/bin/env node
+require('dotenv').config();
+const argv = require('yargs')
+  .usage('Usage: $0 [options]')
+  .option('url', {
+    alias: 'u',
+    describe: 'The URL the crawler should enter the site from',
+  })
+  .option('resume', {
+    alias: 'r',
+    boolean: true,
+    describe: 'Resume crawler from existing queue',
+  })
+  .option('max-radius', {
+    alias: 'm',
+    number: true,
+    describe: 'The maximum radius from the entry URL to crawl',
+    default: Infinity,
+  })
+  .check(({ url, resume }) => {
+    if (url && resume) {
+      throw new Error('--url and --resume are mutually exclusive');
+    }
+    return true;
+  })
+  .help().argv;
+
+const db = require('./db');
+const crawl = require('./crawler');
+
+(async () => {
+  if (!argv.resume) {
+    await db.flush();
+  }
+  await crawl(argv.url, { maxRadius: argv.maxRadius });
+  db.close();
+})();

crawler.js

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+const _ = require('lodash');
+const db = require('./db');
+const puppeteer = require('puppeteer');
+const url = require('url');
+
+const debug = {
+  crawl: require('debug')('crawler:crawl'),
+  page: require('debug')('crawler:page'),
+};
+
+const crawl = async (entry, options = {}) => {
+  debug.crawl('Crawler started');
+  let target = (await db.getCrawlUrl()) || { url: entry, radius: 0 };
+  const { maxRadius = Infinity } = options;
+  if (!target.url) {
+    debug.crawl('Nothing to crawl');
+    return;
+  }
+
+  const entryUrl = url.parse(target.url);
+  const browser = await puppeteer.launch();
+  const page = await browser.newPage();
+  debug.crawl('Puppeteer started');
+
+  let count = 0;
+  while (target) {
+    if (target.radius >= maxRadius) {
+      debug.page(`Max radius reached ${target.url} not scraped`);
+    } else {
+      count++;
+      debug.page(`Crawling: ${target.url}`);
+      await page.goto(target.url);
+      debug.page(`Page loaded`);
+      const links = await page.evaluate(() => {
+        return Array.from(document.querySelectorAll('a')).map(
+          link => link.href
+        );
+      });
+      const urls = _.chain(links)
+        .filter(link => {
+          return url.parse(link).host === entryUrl.host;
+        })
+        .value();
+      debug.page(`Scraped ${urls.length} urls`);
+      await db.addCrawlUrls(urls, ++target.radius);
+    }
+    target = await db.getCrawlUrl();
+  }
+  debug.crawl(`Crawler finished after crawling ${count} pages`);
+
+  browser.close();
+};
+
+module.exports = crawl;

db.js

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+const bluebird = require('bluebird');
+const redis = require('redis');
+
+bluebird.promisifyAll(redis.RedisClient.prototype);
+bluebird.promisifyAll(redis.Multi.prototype);
+
+const debug = {
+  redis: require('debug')('crawler:redis'),
+};
+
+const client = redis.createClient(
+  process.env.REDIS_PORT || 6379,
+  process.env.REDIS_HOST || 'localhost'
+);
+
+module.exports = {
+  addCrawlUrls: async (urls, radius) => {
+    debug.redis('Add scraped urls to redis');
+    const multi = client.multi();
+    urls.forEach(url => {
+      multi.sadd('discoveredPages', url);
+    });
+    const result = await multi.execAsync();
+    debug.redis('Added urls to discovered set');
+
+    let count = 0;
+    result.forEach((notDiscovered, i) => {
+      if (notDiscovered) {
+        count++;
+        const url = urls[i];
+        multi.rpush('pageQueue', `${url} ${radius}`);
+      }
+    });
+    await multi.execAsync();
+    debug.redis(`Added ${count} new urls to queue`);
+    debug.redis(`${urls.length - count} duplicates found`);
+  },
+
+  addCrawlUrl: async (url, radius) => {
+    const notDiscovered = await client.saddAsync('discoveredPages', url);
+    if (!notDiscovered) {
+      await client.rpushAsync('pageQueue', `${url} ${radius}`);
+    }
+  },
+
+  getCrawlUrl: async () => {
+    debug.redis('Pop url from queue');
+    const reply = await client.lpopAsync('pageQueue');
+    if (reply) {
+      debug.redis('Url popped');
+      if (debug.redis.enabled) {
+        const length = await client.llenAsync('pageQueue');
+        debug.redis(`${length} urls in queue`);
+      }
+      const parts = reply.match(/(.+) ([0-9]+)$/);
+      return {
+        url: parts[1],
+        radius: parseInt(parts[2]),
+      };
+    }
+    debug.redis('Queue empty');
+    return null;
+  },
+
+  flush: async () => {
+    debug.redis('Flush db');
+    await client.del('discoveredPages', 'pageQueue');
+    debug.redis('Redis flushed');
+  },
+
+  close: () => {
+    client.end(true);
+  },
+};

package.json

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+{
+  "name": "crawler",
+  "version": "1.0.0",
+  "main": "crawl",
+  "license": "MIT",
+  "author": {
+    "email": "[email protected]",
+    "name": "Reed Dadoune",
+    "url": "https://www.dadoune.com"
+  },
+  "scripts": {
+    "precommit": "lint-staged"
+  },
+  "lint-staged": {
+    "*.{js, jsx}": ["prettier --single-quote --trailing-comma es5 --write", "git add"]
+  },
+  "dependencies": {
+    "bluebird": "^3.5.0",
+    "debug": "^3.0.0",
+    "dotenv": "^4.0.0",
+    "lodash": "^4.17.4",
+    "puppeteer": "^0.9.0",
+    "redis": "^2.8.0",
+    "yargs": "^8.0.2"
+  },
+  "devDependencies": {
+    "husky": "^0.14.3",
+    "lint-staged": "^4.0.3",
+    "prettier": "^1.5.3"
+  }
+}