Mastering the Art of Debugging: VSCode Debugger Attachment to Docker Container

Are you tired of debugging your application in a docker container without a proper debugging tool? Do you struggle to understand the complexity of the docker ecosystem and how to attach a debugger to a running container? Worry no more! In this comprehensive guide, we’ll take you on a journey to master the art of debugging using VSCode and docker.

Why Do I Need a Debugger Attachment?

Debugging is an essential part of the software development life cycle. It’s where you get to understand the nitty-gritty details of your code, identify issues, and fix them. But what happens when you’re working with a docker container? You can’t just attach a debugger to a running container, can you?

Well, you can! With the right tools and configurations, you can attach a debugger to a running docker container, giving you the power to inspect and debug your application in real-time.

Benefits of Debugger Attachment

• Improved debugging experience: With a debugger attached to your docker container, you can step through your code, set breakpoints, and inspect variables in real-time.
• Faster issue resolution: By debugging your application in a more controlled environment, you can identify issues faster and fix them more efficiently.
• Enhanced collaboration: With a debugger attached to your docker container, you can share your debugging experience with colleagues, making it easier to collaborate and resolve issues.

Prerequisites

Before we dive into the world of debugger attachments, make sure you have the following prerequisites:

• Docker installed on your machine
• VSCode installed on your machine
• A docker container running with your application
• The docker and vscode commands available in your terminal

Step 1: Configure Your Docker Container

In this step, we’ll configure our docker container to allow the VSCode debugger to attach to it. We’ll create a new file called docker-compose.yml with the following content:

version: "3"
services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=development
    volumes:
      - .:/app

This configuration tells docker to create a new container from the current directory (.), map port 3000 on the host machine to port 3000 in the container, set the NODE_ENV environment variable to development, and mount the current directory as a volume inside the container.

Step 2: Create a VSCode Debug Configuration

In this step, we’ll create a new debug configuration in VSCode. Open the Command Palette in VSCode by pressing Ctrl+Shift+P (Windows/Linux) or Cmd+Shift+P (Mac), and type “Debug: Open Config” to open the debug configuration file.

Add the following configuration to the file:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Docker: Attach to Node",
      "type": "node",
      "request": "attach",
      "port": 9229,
      "localRoot": "${workspaceFolder}",
      "remoteRoot": "/app"
    }
  ]
}

This configuration tells VSCode to attach to a node process running in a docker container, using port 9229.

Step 3: Start the Docker Container

In this step, we’ll start the docker container using the following command:

docker-compose up

This command tells docker to start the container based on the configuration in the docker-compose.yml file.

Step 4: Attach the VSCode Debugger

In this step, we’ll attach the VSCode debugger to the running docker container. Open the VSCode debug panel by clicking on the debug icon in the left sidebar or pressing Ctrl+Shift+D (Windows/Linux) or Cmd+Shift+D (Mac).

VSCode will now attach to the node process running in the docker container, allowing you to debug your application in real-time.

Step 5: Debug Your Application

In this step, we’ll debug our application using the VSCode debugger. Set a breakpoint in your code, and then interact with your application to trigger the breakpoint.

When the breakpoint is hit, VSCode will pause the execution of the code, allowing you to inspect variables, step through the code, and identify issues.

Troubleshooting Tips

If you encounter issues while attaching the VSCode debugger to your docker container, here are some troubleshooting tips:

• Make sure the docker container is running and the node process is listening on the correct port.
• Verify that the VSCode debugger is configured correctly, and the port numbers match.
• Check that the remoteRoot and localRoot paths are correctly configured in the VSCode debug configuration.

Conclusion

Attaching a debugger to a docker container can seem like a daunting task, but with the right tools and configurations, it’s a breeze! By following the steps outlined in this guide, you can master the art of debugging using VSCode and docker.

Remember, debugging is an essential part of the software development life cycle. With a debugger attached to your docker container, you can identify issues faster, fix them more efficiently, and collaborate with your colleagues more effectively.

Happy debugging!

Resource	Link
VSCode Debugger Documentation	https://code.visualstudio.com/docs/editor/debugging
Docker Documentation	https://docs.docker.com/

By following this guide, you’ll be well on your way to becoming a debugging master. Remember to practice, experiment, and learn from your experiences.

Stay curious, and happy coding!

Frequently Asked Questions

Debugging in Docker containers can be a real challenge, but don’t worry, we’ve got you covered! Here are some FAQs about VSCode debugger attachment to Docker containers.