Featured image of post Using Lima on Mac as Linux Environment
Linux

Using Lima on Mac as Linux Environment

Sharing my experience with installing and using lima, along with the problems I encountered. Because I recently wanted to try picoCTF and needed a Linux environment, I decided to use lima as my Linux container. This article records the complete installation, usage, and problem-solving process.

(Old blog post, written: 2022-07-05)

Using Lima on Mac as Linux Environment

Table of Contents

  1. Installation
  2. Usage
  3. Problem 1 (Read-write issue)

Preface

Because I recently wanted to try picoCTF, I needed a Linux environment. Since I’m using macOS, which isn’t Linux, although some commands are universal, there are significant differences in program execution results. So I decided to use lima as my Linux container. I had originally considered using VMWare virtual machine, but the thought of making this old MacBook Pro (late 2013) suffer every time I wanted to play CTF made me feel bad.

And that’s exactly what happened - as soon as I started VMWare, my old partner’s fan started whining again 🤧.

Installation

I installed it using homebrew. Remember to download it from the official website. First, enter the following commands:

$ brew install lima # Install lima
$ limactl start # Install virtual machine

When the following screen appears, use arrow keys up and down to select configuration. We just need to use the default, so press enter directly. When you see READY, it’s completed!

? Creating an instance "default"  [Use arrows to move, type to filter]
> Proceed with the default configuration
  Open an editor to override the configuration
  Exit
...
INFO[0111] READY. Run `lima` to open the shell.

After downloading is complete, you can run lima uname -a to confirm the virtual machine is running

$ Linux lima-default 5.15.0-39-generic #42-Ubuntu SMP Thu Jun 9 23:42:32 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Usage

Simply type lima in the terminal to run it. To exit, just type exit. (When I first installed it, I didn’t know how to exit, so I used two terminal windows - one for lima and one for zsh. Don’t be as silly as me qq) If you’re not using the virtual machine, remember to turn it off, otherwise it will silently eat up your memory. Type lima stop [virtual-machine-name] to close the virtual machine.

Demo

As for the container part, I haven’t researched it yet. This is lima’s strong point - it’s claimed to be able to become a macOS Subsystem Linux that replaces docker. But since I just need a convenient Linux environment to practice CTF, interested friends can refer to the lima source code.

Problem 1 (Read-write issue)

If you want to use the mkdir command in lima, or simply edit a file with vim, you might see this line: lima mkdir cannot create directory Read-only file system

When I was looking for information, I found this Q&A. I originally thought it was a system data problem, but my situation seemed different from his. Later I found this lima Github issue and discovered it was actually a lima configuration file problem. The following commands can be used in both zsh or bash. If you use them in lima shell, you’ll find this file doesn’t exist. Basically, just open Mac’s original terminal. The solution is as follows:

  1. Modify configuration file
$ vim ~/.lima/default/lima.yaml # First edit the configuration file with vim.
# It's quite long so I won't paste it here. Find writable: null and change it to writable: true
writable: null -> writable: true
  1. Restart lima
$ limactl list  This command lists all running virtual machines. I saw one named default
$ limactl stop default  Stop it from running, default can be replaced with your virtual machine name
$ limactl start default  Same as above, default can be replaced with your virtual machine name
  1. Congratulations, you succeeded!

References

lima source code Reference (lima issue 34) Reference (lima configuration file)