Minimal Terminals in Docker🐳: Why Your Ubuntu Isn’t Really Ubuntu (Yet!)

“Why is clear not found, but vim works just fine in my Docker container?”
That was my exact question recently, and the answer opened up a fun learning rabbit hole.

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🔹 Setting the Scene

I spun up an Ubuntu container on Docker Desktop for testing scripts:

docker run -it ubuntu bash

All good so far. Then I typed:

clear

And got this:

bash: clear: command not found

Wait, what?

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🔍 Why Some Commands Are Missing

The Ubuntu image from Docker Hub is intentionally minimal. It’s designed to run light and fast, so it doesn’t include full utilities unless absolutely necessary.

🧱 For example:

• clear needs ncurses-bin, which isn’t installed by default.

• ping needs iputils-ping → also missing.

• htop, curl, wget, and friends? You’ll need to install them manually.

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🤔 But vim Works?!

Yes → and here’s the catch:

Most minimal Ubuntu images include vim.tiny by default → a stripped-down version of Vim with just the essentials. It’s often aliased or symlinked as vim.

So while it’s not the full vim package, it’s good enough for quick edits inside a container.

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🔧 Fixing Missing Tools

If you want your container to feel like a “real” Linux machine:

apt update && apt install -y ncurses-bin iputils-ping curl

Want full Vim?

apt install vim

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💡 Why Use Minimal Terminals at All?

✅ Pros:

• Smaller size (faster pulls)

• Fewer dependencies (more secure)

• Clean base for custom images

❌ Cons:

• Missing familiar commands

• Not beginner-friendly

• Troubleshooting requires extra installs

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🛠 Pro Tip: Build a Dev-Friendly Ubuntu Container

Here’s a simple Dockerfile if you want a full Linux playground inside Docker:

FROM ubuntu:latest

RUN apt update && apt install -y \
    vim curl iputils-ping net-tools htop ncurses-bin

Build and run it:

docker build -t my-dev-ubuntu .
docker run -it my-dev-ubuntu

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👨‍💻 Final Thought

Docker containers can feel minimal because they are.
But with just a few commands, you can transform them into powerful Linux environments for testing, scripting, or learning.

Next time something doesn’t work inside a container, take a pause and ask:
“Is it missing… or just not installed yet?”

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