Colima - Docker Desktop Alternative That Doesn't Suck

Docker Desktop's 2021 licensing changes pissed off a lot of developers. One day it's free, the next your company gets a bill for $5/month per developer. That's when I started looking at alternatives, and Colima turned out to be exactly what I needed.

Docker Desktop Was Killing My MacBook

I was running a 2019 MacBook Pro with 16GB RAM, and Docker Desktop was eating 1.5-2GB just sitting there. Startup took 30+ seconds, and my laptop fan would spin up like a jet engine whenever I pulled images. The GUI was pretty but useless - who clicks around Docker Desktop when you can use the CLI?

After switching to Colima, my memory usage dropped to around 200MB for the VM when idle. Container startups went from 10-15 seconds to 2-3 seconds. The fan noise? Gone. My laptop actually felt responsive again.

What Colima Actually Is

Colima wraps Lima (Linux virtual machines) specifically for container workloads. It uses Apple's Virtualization Framework on macOS 13+ (falls back to QEMU on older systems) to run an optimized Linux VM that Docker connects to.

The difference is philosophy: Docker Desktop tries to be everything to everyone. Colima just runs containers efficiently. No GUI bloat, no unnecessary services, no Docker Scout nagging you about vulnerabilities.

Real Performance Bullshit

I won't give you synthetic benchmarks because your setup's different. What I can tell you from daily use:

• Cold starts: Colima usually boots in 5-10 seconds, sometimes 15 if my Mac's being shitty
• Memory overhead: ~150MB idle, but spikes during large builds obviously
• Image pulls: Feels faster but that's probably just less overhead competing for resources
• Build times: About the same, maybe 10% faster? Hard to tell without controlled testing
• File sync occasionally shits the bed with large node_modules folders

The biggest win isn't raw speed - it's that Colima doesn't make your whole system feel sluggish when running in the background. Docker Desktop constantly spinning my fan was driving me insane.

Where I've Seen It Break

Nothing's perfect. Version 0.8.4 (released August 6, 2024) fixed some nasty cross-architecture bugs, but I've hit these issues over 2+ years:

• macOS 14.1 update completely broke my VM - had to nuke and rebuild everything
• K3s crashed randomly when running 6+ pods (memory pressure, learned the hard way)
• File sync occasionally shits the bed with large node_modules folders - takes forever to sync
• Cross-architecture builds were fucked until 0.8.4 fixed the "exec /bin/sh: exec format error" bullshit
• Docker socket permissions get screwed up after some macOS updates - sudo chown fixes it
• VM corruption when my MacBook crashes during a build (happened twice, lost everything)

The GitHub issues are your lifeline when shit breaks. The maintainer is responsive but it's basically a one-person project, so don't expect Docker Inc level support.

Why It's Worth the Switch

If you're paying for Docker Desktop licenses or your Mac feels sluggish, try Colima. Installation takes 5 minutes with Homebrew. Worst case, you uninstall it and go back to Docker Desktop.

The CLI-first approach means it works great in CI/CD. No GUI to break, no licensing to worry about, just containers.

Installation That Usually Works

Use Homebrew unless you enjoy pain:

brew install colima docker
colima start

That's it. If it doesn't work on the first try, welcome to the club. Check the installation guide for alternatives.

When Installation Goes Wrong

On M1 Macs with old Homebrew: You might get architecture errors. Fix with:

arch -arm64 brew install colima docker

If you have Docker Desktop running: Stop it first or they'll fight over the Docker socket:

## Kill Docker Desktop completely
osascript -e 'quit app \"Docker\"'

WSL2 on Windows: Officially unsupported but some masochists make it work. Good luck.

Common Setup Issues I've Hit

"Cannot connect to the Docker daemon" error: The Docker socket path is probably fucked. Check with:

ls -la ~/.colima/default/docker.sock

If it's missing, your VM didn't start properly or died silently (happens more than it should). Nuclear option:

colima delete
colima start --cpu 4 --memory 6

Took me 3 hours to figure this out the first time because the error message is useless.

M1 Mac won't run x86 images: You need Rosetta 2 enabled:

colima start --vm-type vz --vz-rosetta --arch aarch64

Note: --vz-rosetta only works on macOS 13+ with the VZ framework.

Memory and CPU Settings That Don't Suck

Default settings (2GB RAM, 2 CPUs) are garbage for real work. I run:

colima start --cpu 4 --memory 8 --disk 100

More than 8GB RAM usually doesn't help unless you're building huge images. Disk space is cheap - start with 100GB.

Real talk on resources: I tried running with 2GB RAM and my Node.js builds kept getting OOMKilled. Bumped to 8GB and builds that were failing now finish in 5 minutes instead of timing out after 20 minutes of thrashing.

Profiles Are Actually Useful

Unlike Docker Desktop, you can run multiple setups:

## Light dev environment
colima start --profile dev --cpu 2 --memory 4

## Heavy lifting for builds  
colima start --profile build --cpu 6 --memory 12

## Kubernetes testing
colima start --profile k8s --cpu 4 --memory 8 --kubernetes

Switch between them without restarting everything:

colima stop --profile dev
colima start --profile build

The Kubernetes Situation

Colima's K8s is K3s, not full Kubernetes. It works for:

• Development testing
• Simple workloads
• Learning Kubernetes

It doesn't work for:

• Production-like testing
• Complex networking scenarios
• Anything requiring Kubernetes features K3s doesn't support

Don't expect feature parity with Docker Desktop's K8s.

Docker Socket Path Hell

If you're switching from Docker Desktop, some tools might still look for the old socket. Set this in your shell profile:

export DOCKER_HOST=\"unix://$HOME/.colima/default/docker.sock\"

VS Code Dev Containers should pick this up automatically. If not, restart VS Code.

When Everything Breaks

This is your nuclear option:

colima delete --force
rm -rf ~/.colima
brew uninstall colima docker
brew install colima docker
colima start --cpu 4 --memory 8

Usually fixes weird VM corruption issues after macOS updates.