brozzler 1.7.0

Distributed web crawling with browsers

“browser” | “crawler” = “brozzler”

Brozzler is a distributed web crawler (爬虫) that uses a real browser (Chrome or Chromium) to fetch pages and embedded URLs and to extract links. It employs yt-dlp (formerly youtube-dl) to enhance media capture capabilities and rethinkdb to manage crawl state.

Brozzler is designed to work in conjunction with warcprox for web archiving.

Requirements

• Python 3.8 or later

• RethinkDB deployment

• Chromium or Google Chrome >= version 64

Note: The browser requires a graphical environment to run. When brozzler is run on a server, this may require deploying some additional infrastructure, typically X11. Xvnc4 and Xvfb are X11 variants that are suitable for use on a server, because they don’t display anything to a physical screen. The vagrant configuration in the brozzler repository has an example setup using Xvnc4. (When last tested, chromium on Xvfb did not support screenshots, so Xvnc4 is preferred at this time.)

Getting Started

The simplest way to get started with Brozzler is to use the brozzle-page command-line utility to pass in a single URL to crawl. You can also add a new job defined with a YAML file (see job-const.rst) and start a local Brozzler worker for a more complex crawl.

Mac instructions:

# install and start rethinkdb
brew install rethinkdb
# no brew? try rethinkdb's installer: https://www.rethinkdb.com/docs/install/osx/
rethinkdb &>>rethinkdb.log &

# optional: create a virtualenv
python -m venv .venv

# install brozzler with rethinkdb extra
pip install brozzler[rethinkdb]

# crawl a single site
brozzle-page https://example.org

# or enqueue a job and start brozzler-worker
brozzler-new-job job1.yml
brozzler-worker

At this point Brozzler will start archiving your site.

Running Brozzler locally in this manner demonstrates the full Brozzler archival crawling workflow, but does not take advantage of Brozzler’s distributed nature.

Installation and Usage

To install brozzler only:

pip install brozzler  # in a virtualenv if desired

Launch one or more workers: [*]

brozzler-worker --warcprox-auto

Submit jobs:

brozzler-new-job myjob.yaml

Submit sites not tied to a job:

brozzler-new-site --time-limit=600 https://example.org/

[*]

A note about --warcprox-auto: this option tells brozzler to look for a healthy warcprox instance in the rethinkdb service registry. For this to work you need to have at least one instance of warcprox running, with the --rethinkdb-services-url option pointing to the same rethinkdb services table that brozzler is using. Using --warcprox-auto is recommended for clustered deployments.

Job Configuration

Brozzler jobs are defined using YAML files. Options may be specified either at the top-level or on individual seeds. At least one seed URL must be specified, however everything else is optional. For details, see job-conf.rst.

id: myjob
time_limit: 60 # seconds
ignore_robots: false
warcprox_meta: null
metadata: {}
seeds:
  - url: https://one.example.org/
  - url: https://two.example.org/
    time_limit: 30
  - url: https://three.example.org/
    time_limit: 10
    ignore_robots: true
    scope:
      surt: https://(org,example,

Brozzler Dashboard

Brozzler comes with a rudimentary web application for viewing crawl job status. To install the brozzler with dependencies required to run this app, run

pip install brozzler[dashboard]

To start the app, run

brozzler-dashboard

At this point Brozzler Dashboard will be accessible at http://localhost:8000/.

See brozzler-dashboard --help for configuration options.

Headless Chrome (experimental)

Brozzler is known to work nominally with Chrome/Chromium in headless mode, but this has not yet been extensively tested.

License

Copyright 2015-2024 Internet Archive

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this software 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.