Docker Playground

What is This and Why?

Want to try a Docker command, build someone else's Dockerfile, or inspect a suspicious container image without cluttering your laptop?

iximiuz Labs' Docker playground gives you a fresh Linux server with Docker Engine pre-installed and ready to use. It starts in seconds, opens in your browser, and behaves like a regular remote machine: you get a shell, root access, a real Linux kernel, and enough freedom to install additional tools or reconfigure the system as needed.

This is not a limited Docker-in-Docker shell. The playground is a lightweight but fully fledged VM running on iximiuz Labs' bare-metal infrastructure. Docker runs directly on the VM, much like it would on a VPS, a cloud instance, or a server in your homelab—only this machine is disposable, so experiments are much less stressful.

Break Docker, fill the disk with images, misconfigure the daemon, or run a container you don't fully trust. If things go sideways, simply destroy the playground and start a clean one.

A good place to learn Docker

If you're new to containers, the playground is a convenient companion for tutorials, books, videos, and the Hands-On Docker Roadmap.

Some good first exercises are:

• Run a container and inspect its logs, processes, filesystem, and network settings.
• Practice starting, stopping, restarting, and removing containers.
• Publish ports and see how traffic reaches a container from the host.
• Mount bind mounts and Docker volumes, then observe what survives a container replacement.
• Create user-defined networks and connect several containers into a small application stack.
• Write a Dockerfile, build an image, and compare the resulting layers.
• Push and pull images from a container registry.
• Turn a multi-container setup into a Compose project.

The learning happens in the doing. Don't worry about memorizing every flag upfront—pick a small task, inspect the system after each command, break the setup a few times, and gradually build the right mental model.

Build, test, and troubleshoot container images

The Docker playground is also handy when you already use containers daily and simply need a clean machine for a one-off job.

Clone a repository and test its Dockerfile without changing your local Docker cache. Build an image for a different project. Compare a few base images. Check why a build stopped using the cache, why an entrypoint fails, or why the final image is unexpectedly large. Install tools such as dive, skopeo, regctl, or an image scanner when the task calls for them, then throw the entire environment away when you're done.

This isolation is especially useful for third-party projects. A Docker build can execute arbitrary commands, and a Compose file may start privileged containers, mount host directories, or publish unexpected ports. A disposable remote VM keeps those experiments away from your primary system. It is still a real server, though, so treat secrets, production credentials, and sensitive data exactly as you would on any other temporary machine: don't put them here unless the task genuinely requires it and you understand the implications.

Run and share containerized applications

A container that only answers curl inside the VM is useful, but sometimes you need to open its UI in a browser or show it to someone else.

Publish the container port on the playground host as usual:

docker run -d --name web -p 8080:80 nginx:alpine

Then use Expose Port to give the service a generated HTTPS URL. Exposed services are private by default, but you can make a URL public when you want to share a demo, test a webhook, show a work-in-progress application to a colleague, or access the service from another device.

For the service to be exposable, publish it on the VM's main interface or on all interfaces (0.0.0.0), as the command above does. A process listening only on 127.0.0.1 cannot be reached by the playground ingress directly.

This makes the playground a practical home for short-lived web applications, API prototypes, observability dashboards, self-hosted developer tools, and full Compose stacks. It is particularly useful for demos: you can prepare the environment beforehand, expose the UI, and keep your laptop free from the traditional conference-demo collection of mystery containers and forgotten volumes.

Use it as a remote Docker host or builder

You don't have to work inside the browser terminal. Every playground VM is accessible over SSH, either with the labctl CLI or through a standard SSH connection. That means you can edit files with your local IDE, copy a project to the VM, or run one-off commands from scripts.

With a Docker context, your local docker CLI can control the playground's Docker daemon over SSH. From your terminal, it feels almost like using local Docker, while the containers and images actually live on the remote VM. This is a good fit when your laptop is short on CPU, RAM, or disk space—or when you simply don't want Docker-related leftovers on it.

The same setup can act as a remote Buildx builder. Keep the source code and CLI on your machine, perform the expensive build remotely, and either load or push the resulting image. It's a small but surprisingly capable alternative to provisioning a temporary cloud VM just to test a build.

Experiment freely—or keep your progress

The default workflow is intentionally ephemeral: start a clean Docker host, perform the experiment, and destroy it when you're finished. No cleanup commands, no dangling networks, and no wondering whether today's result depends on an image you pulled six months ago.

Not every useful setup fits into one sitting, though. If you want to return later, stop the playground instead of destroying it. Its disk state can be preserved and restarted in a future session. A stopped run can also be forked, which is handy when you want to test several approaches from the exact same starting point.

And if an ad hoc experiment turns into something worth reusing, save it as a custom playground. The installed packages, cloned repositories, images, configuration, and other filesystem changes become a template for future runs. Add a clear description and you can use it for a workshop, attach it to a tutorial, share a reproducible bug report, or give teammates an identical environment.

Where this playground fits

Use the Docker playground for learning, experimentation, debugging, short-lived development environments, and demos. Think of it as a remote workbench: realistic enough to behave like a server, but cheap to reset when the workbench gets messy.

For everything else, start the VM and get your hands dirty. The fastest way to understand Docker is to run containers, inspect what changed, and keep asking the Linux system underneath what Docker actually did.

Happy hacking!