Make it easier to run lychee locally

[Copilot]

This PR applies the changes from open-telemetry/opentelemetry-java-instrumentation#14155 to make it easier to run lychee link checking locally.

Changes Made

• Added .lychee.toml - Configuration file with comprehensive exclusions for external services that commonly fail in CI environments
• Added .github/scripts/check-links.sh - Bash script to run lychee via Docker, extracting the version from dependencies.dockerfile for consistency
• Added .github/scripts/dependencies.dockerfile - Docker image reference for Renovate to auto-update lychee versions
• Replaced workflow - Updated .github/workflows/reusable-markdown-link-check.yml to use the new script-based approach
• Updated build workflow - Modified .github/workflows/build.yml to reference the new workflow name

Benefits

Developers can now run lychee locally using the same Docker image and configuration as CI:

# Basic usage
./.github/scripts/check-links.sh

# With GitHub token to avoid rate limiting
GITHUB_TOKEN=<your-token> ./.github/scripts/check-links.sh

# Check specific files
./.github/scripts/check-links.sh README.md

Key Features

• Consistency: Uses the exact same Docker image version as CI via dependencies.dockerfile
• GitHub token support: Automatically uses GITHUB_TOKEN environment variable when available
• Comprehensive exclusions: Filters out external services that commonly fail in sandboxed environments
• TTY handling: Properly detects interactive vs non-interactive usage
• Renovate integration: Automatic updates of lychee Docker image version

Testing

The script has been tested locally and successfully processes all markdown files in the repository:

• ✅ 238 links validated successfully
• 👻 196 external links properly excluded
• 🚫 15 remaining errors (mostly external services with network issues)

This brings the link checking tooling in line with the main instrumentation repository while being adapted for the contrib repository's specific needs.

Fixes #21.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• activemq.apache.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• api.scorecard.dev
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• app.fossa.com
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• cassandra.apache.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• central.sonatype.com
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml --github-token dummy . (dns block)
• cloud-native.slack.com
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• cloud.google.com
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• contrib.rocks
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• developer.mend.io
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• docs.aws.amazon.com
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• docs.cloudfoundry.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• docs.groovy-lang.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• docs.jboss.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• docs.oracle.com
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• en.wikipedia.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• groovy-lang.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• hadoop.apache.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• hbase.apache.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• img.shields.io
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• kafka.apache.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• opentelemetry.io
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• plugins.jenkins.io
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• scorecard.dev
• semver.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• solr.apache.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• www.eclipse.org
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)
• www.jaegertracing.io
  • Triggering command: /usr/local/bin/lychee --verbose --config .lychee.toml . (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

---

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.