Romain Filirom1

Nix + Composefs: symlink reduction POC

Work in Progress — POC only

The context: old PCs running Windows 10 that can't upgrade to Windows 11. End-of-life is coming, migration isn't an option. The idea is to replace Windows with NixOS — but these machines have spinning HDDs where boot time is a real concern.

This POC is a first step to understand whether Composefs could help reduce the symlink overhead in the Nix store. I'd like to keep testing the actual impact before drawing any conclusions.

Extracted from https://github.com/appuio/openshift-scripts/blob/master/openshift-backup.sh#L53-L64

Install Golang

On a fresh CentOS 7.4, as root:

yum install -y golang git wget

	package main

	import (
	"encoding/binary"
	"fmt"
	"io"
	"log"
	"net"
	"os"
	"strconv"

	vagrant init centos/7
	vagrant up && vagrant ssh
	sudo yum install -y epel-release && sudo yum install -y docker npm git
	git clone https://github.com/portainer/portainer.git && cd portainer
	sudo ln -s /usr/bin/sha1sum /usr/bin/shasum
	npm install && sudo npm i -g grunt
	sudo systemctl start docker && sudo chmod o+rw /var/run/docker.sock && sudo setenforce 0
	grunt build
	grunt run-dev

	require 'logger'

	module Dim
	class Logger < ::Logger
	def initialize(*)
	super
	@formatter = NoTimestampFormatter.new
	end
	end

	#!/usr/bin/env
	docker run --interactive --tty --rm --env CODECLIMATE_CODE="$PWD" --volume "$PWD":/code --volume /var/run/docker.sock:/var/run/docker.sock --volume /tmp/cc:/tmp/cc codeclimate/codeclimate engines:install
	docker run --interactive --tty --rm --env CODECLIMATE_CODE="$PWD" --volume "$PWD":/code --volume /var/run/docker.sock:/var/run/docker.sock --volume /tmp/cc:/tmp/cc codeclimate/codeclimate analyze -f text