linkmedic 0.9.0

Website links checker

A Python script for checking links and resources used in local static webpages (.htm, .html), OpenDocument files (.odt, .odp, .ods), and single OpenDocument XML files (.fodt, .fodp, .fods).

linkmedic starts a test web server, requests an entry page from the server, and crawls all local pages. It checks all links within specific HTML tags (<a> <img> <script> <link> <iframe> <event-listener>) and reports any dead links found. If a link appears on multiple pages, it is tested only once to avoid redundant checks. By default, links to the external websites are ignored. If there is a .linkignore file in the website’s root, links matching the regular expressions listed in this file (one link per line; see below for examples) are also ignored during testing. After checking all the links, if any dead links are discovered, linkmedic exits with a non-zero status code.

For testing links in dynamic HTML content (e.g., using JavaScript template engines) or other document formats, you must first convert your files (using a third-party tool) to static HTML and then run linkmedic.

Quick start

Install prerequisites

Depending on your operating system, you may have multiple options for installing the prerequisites:

• Python: linkmedic is only tested on officially supported Python versions.

• A Python package installer: For example, pip

Install linkmedic

You can install the linkmedic using your favorite Python package installer. For example, using pip, you can download it from PyPI:

pip install linkmedic

Run

To start a test web server with files at /var/www and crawl the pages and test all the links starting from the /var/www/index.html page, run:

linkmedic --root=/var/www

Usage & Options

Mirror package repository

You can also install linkmedic from the MPCDF GitLab package repository:

pip install linkmedic --index-url https://gitlab.mpcdf.mpg.de/api/v4/projects/5763/packages/pypi/simple

Container

You can use one of the container images, which have the required libraries and linkmedkit already installed:

quay.io/meisam/linkmedic:latest

gitlab-registry.mpcdf.mpg.de/tbz/linkmedic:latest

You can access a specific version of linkmedic using container tags e.g. linkmedic:v0.7.4 instead of linkmedic:latest. See all available container tags here.

When using a container image, linkmedic’s test web server needs to have access to the files for your website pages from inside the container. Depending on your container engine, you may need to mount the path to your files inside the container. For example, using podman:

podman run --volume /www/public:/test quay.io/meisam/linkmedic:latest linkmedic --root=/test

Here, the --volume /www/public:/test flag mounts the directory /www/public inside the container at the path /test.

CI/CD

You can also use the container image in your CI/CD pipelines. For example, for GitLab CI, in the .gitlab-ci.yml file:

test_internal_links:
  image: quay.io/meisam/linkmedic:latest
  script:
    - linkmedic --root=/var/www/ --entry=index.html --warn-http --with-badge
  after_script:
    - gitlab_badge_sticker.sh

or for Woodpecker CI in the .woodpecker.yml file:

test_internal_links:
  image: quay.io/meisam/linkmedic:latest
  commands:
    - linkmedic --root=/var/www/ --entry=index.html --warn-http

If you want to check the external links of your website in your CI pipeline, you must avoid running multiple tests in a short period of time, e.g., on each commit to the development branches. Otherwise, the IP address of your CI runners may get banned by external web servers. For example, in GitLab CI, you can limit the external link checks to only the default branch of your Git repository:

test_external_links:
  image: quay.io/meisam/linkmedic:latest
  rules:
    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
  script:
    - linkmedic --root=/var/www/ --ignore-local --with-badge
  after_script:
    - gitlab_badge_sticker.sh
  allow_failure: true

Please note that the gitlab_badge_sticker.sh script used in these examples requires an API access token CI_API_TOKEN with maintainer permission to modify the GitLab repository badges. See the linkmedkit documentation for more details.

CLI reference

• Display help: This will show all the command-line options and their default values.

linkmedic -h

• Start the web server with the current directory as the root path of the server. Starting from index.html, crawl the pages and test all the links.

linkmedic

• Start the web server with ./tests/public1/ as the root path of the server. Starting from index.html, crawl the pages and test all the links.

linkmedic --root=./tests/public1/

• Start the web server with ./tests/public1/ as the root path of the server. Starting from index2.html, crawl the pages and test all the links. The entry point should be relative to the server root. (In the example, index2.html should be accessible at ./tests/public1/index2.html)

linkmedic --root=./tests/public1/ --entry=index2.html

• Configure the test web server not to redirect missing local pages (e.g., from /directory/page to /directory/page.html).

linkmedic --no-local-redirect

• Check links to external websites.

  [IMPORTANT: You must avoid running the link checker on external links multiple times in a short period, e.g., on each commit to the development branch. Otherwise, the IP address of your machine (or CI runners) may get banned by the CDN or the DoS mitigation solution of the external web servers. See the CI/CD section for a solution.]

linkmedic --check-external

• Do not follow external link redirections. Depending on the configuration of external web servers, this option can result in some dead links not being detetcted when instead of returning 404 page directly, the webserver is asking the client to load another page.

linkmedic --no-external-redirects

• Ignore local dead links and activates external link checking.

linkmedic --ignore-local

• Do not consider external links that return HTTP status codes 403 and 503 as dead links.

linkmedic --ignore-status 403 503

• Check links in an OpenDocument file (e.g., .odt, .odp, .ods), or a single OpenDocument XML file (e.g., .fodt, .fodp, .fods).

linkmedic --entry=./presentation.odp

• Show warning for HTTP links.

linkmedic --warn-http

• If any link to mydomain.com is encountered, treat it as an internal link and resolve it locally.

linkmedic --domain=mydomain.com

• Start the web server on port 3000. If the web server cannot be started on the requested port, the initializer will automatically try the next available ports.

linkmedic --port=3000

• Generate badge information file. Depending on the type of diagnosis, this file will be named badge.dead_internal_links.json, badge.dead_external_links.json, or badge.dead_links.json. If the --warn-http flag is used, a badge file for the number of discovered HTTP links will also be written to the badge.http_links.json file. These files can be used to generate badges (see linkmedkit scripts) or to serve as a response for the shields.io endpoint.

linkmedic --with-badge

• Check the links but always exit with code 0.

linkmedic --exit-zero

• Log the output at a different level of verbosity. If more than one of these flags is defined, the most restrictive one will be in effect.

  • --verbose : log debug information

  • --quiet : log only errors

  • --silent : completely silence the output logs

• Dump the crawler links list to the linkmedic.links file. If the --domain flag has not been set, local links will be referenced from the website root as /your/path/page.html.

linkmedic --dump-links

.linkignore

Each line in the .linkignore file specifies a regex pattern for addresses that should be ignored during link checks. Note that regex matches . to any character (use \. for matching only to .) and the leading / is considered when matching local links.

/ignore/.*/this
/invalidfile\.tar\.gz
/will_add/later\.html
https://not\.accessible\.com

Development

This project uses PDM for packaging and dependency management, vermin and bandit for validation, black and isort for code styling, and check-jsonschema and jq for testing. See the developers guide for more details.

History

The original idea for this project came from Dr. Klaus Reuter (MPCDF). Fruitful discussions with Dr. Sebastian Kehl (MPCDF) facilitated the packaging and release of this project.

Accompanying tools for linkmedic have been moved to a separate repository (linkmedkit) starting with version 0.7.

License

• Copyright 2021-2023 M. Farzalipour Tabriz, Max Planck Computing and Data Facility (MPCDF)

• Copyright 2023-2025 M. Farzalipour Tabriz, Max Planck Institute for Physics (MPP)

All rights reserved.

This software may be modified and distributed under the terms of the 3-Clause BSD License. See the LICENSE file for details.