Traefik Plugin Development Environment

This project provides a preconfigured development environment for building and testing Traefik plugins in Local Plugins mode.
It is based on a VS Code Dev Container and a docker-compose setup that runs Traefik, a test service (whoami), and your local plugin together.

Purpose

The goal of this project is to offer a consistent, reproducible, and convenient environment for Traefik plugin development, supporting both local unit tests and integration tests with a running Traefik instance.

This configuration enables:

• Development of Traefik plugins in Go with full IDE support (IntelliSense, linting, debugging).
• Automated provisioning of a Traefik test setup with the whoami service via docker compose.
• Fast development feedback loop through tasks for starting, restarting, and viewing logs.

Architecture Overview

• Dev Container (VS Code)
  Contains the Go toolchain, Delve debugger, and additional tools for plugin development.
• Traefik Container
  Loads the plugin in Local Plugins mode and exposes it via a configured router.
• Whoami Container
  Minimal HTTP test service to validate plugin behavior.

Go Toolchain in the Dev Container – Purpose and Benefits

Traefik plugins in Local Plugins mode are not shipped as precompiled Go binaries.
Instead, Traefik loads the plugin source code at runtime and interprets it using Yaegi.
Therefore, a Go installation inside the Traefik container is not required for execution.

However, having a Go toolchain in the development environment is recommended for:

1. Running Unit Tests
   Test plugin logic in isolation from Traefik (go test ./...) to significantly reduce the feedback loop.

2. Modern Development Tooling
   Code completion, navigation, static analysis (go vet, staticcheck), and refactoring tools are readily available.

3. Dependency Management
   Commands like go mod tidy keep go.mod and go.sum consistent, preventing runtime errors when Traefik loads the plugin.

4. Quality Assurance
   Local tests and static analysis help catch issues early and improve long-term maintainability.

Conclusion:
The Go installation in the Dev Container exists solely for development and quality assurance.
Traefik itself does not require Go to execute Local Plugins.

Start & Test

1. VS Code: Open the project in VS Code and select “Reopen in Container”.
2. Start Traefik: Run the VS Code task compose up.
3. Verify functionality:

   curl -i -H "Host: demo.localhost" http://localhost:8080/

   The response should contain the HTTP header X-Plugin: Hello.
4. Change code & retest:
   After modifying the plugin code, run the VS Code task compose restart traefik and repeat the test command.

Requirements

• Docker and Docker Compose
• Visual Studio Code with the Dev Containers Extension
• Shared project directories in Docker Desktop (on Windows/macOS)

License

MIT