Ubuntu setup for Plutus Pioneer Program

Credits

Notes

These instructions were tested on Ubuntu 20.04

Note Part of what Nix will be doing is downloading a lot of build artifacts from IOG to make the compilation processes take a lot less time. It means the difference between 10 minute builds versus 3+ hour builds. The down-side is this data will be quite large on your local system and you should expect another 15G minimum to be used by it. Something to think about before going further, if more disk space is needed than you have on your system.

Install Nix and set up cache

Nix can be installed single-user or multi-user

More detailed info can be found in the Nix Package Manager Guide

single-user

Single-user Nix installation has advantages. - No daemon and socket are created - A group of 32 nix users doesn't get created on the system - Nothing is written into /etc

The single-user Nix installer requires curl

sudo sh -c 'apt update && apt install curl'

Install nix

sh <(curl -L https://nixos.org/nix/install) --no-daemon

The installer should create the /nix directory for you with the proper permissions. When it's done you will see

Installation finished!  To ensure that the necessary environment
variables are set, either log in again, or type

  . /home/<youruser>/.nix-profile/etc/profile.d/nix.sh

Execute the above command now to set the environment in this shell (also logout/login will achieve this)

Make sure the changes the installer just made to your ~/.profile make sense.

Next we will add IOG's caches to Nix to speed up our development significantly by using their build artifacts. This is very important and means the difference between 3+ hours and less than 10 minutes!

mkdir ~/.config/nix
echo 'substituters = https://hydra.iohk.io https://iohk.cachix.org https://cache.nixos.org/' >> ~/.config/nix/nix.conf
echo 'trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=' >> ~/.config/nix/nix.conf

multi-user

If you decide you'd like to go with multi-user Nix, read on.

The multi-user Nix installer requires curl and rsync

sudo sh -c 'apt update && apt install curl rsync'

Install nix

sh <(curl -L https://nixos.org/nix/install) --daemon

This will run a wizard, prompting you for some things. When it's done we need to set the environment in this shell (also logout/login will achieve this)

. /etc/profile.d/nix.sh

sudo sh -c "echo 'substituters = https://hydra.iohk.io https://iohk.cachix.org https://cache.nixos.org/' >> /etc/nix/nix.conf"
sudo sh -c "echo 'trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=' >> /etc/nix/nix.conf"
sudo systemctl restart nix-daemon.service

Optionally add your shell account to the Nix trusted users in order to apply the Nix trusted public keys for your builds, e.g.:

sudo sh -c 'echo "trusted-users = $0" >> /etc/nix/nix.conf' `whoami`
sudo systemctl restart nix-daemon.service

After either Nix installation method

If everything worked you should be able to run a nix program

nix-env --version

and see output like this, version may vary

nix-env (Nix) 2.3.14

Miscellaneous

Completely uninstalling Nix

Nix (unfortunately) installs with a non-distro-specific and not-reversible method and so requires careful unistallation if you don't want it any longer. The Nix documentation says simply removing /nix is the way but this leaves a lot of unneeded files on your system. We can clean this up properly.

These instructions work equally well for single- or multi-user Nix.

First, disable and stop the systemd units if they exist. This is harmless to do if they don't exist.

sudo systemctl disable --now nix-daemon.service
sudo systemctl disable --now nix-daemon.socket

Then delete the many directories and files that are on the system

rm -rf $HOME/{.nix-*,.cache/nix,.config/nix}
sudo rm -rf /root/{.nix-channels,.nix-defexpr,.nix-profile,.config/nixpkgs,.cache/nix}
sudo rm -rf /etc/{nix,profile.d/nix.sh*}
sudo rm -rf /nix

Now we will remove the 32(!) nixbld users that were added to the system for a multi-user installation.

sudo sh -c 'for N in $(seq 32); do deluser "nixbld$N"; done'

Finally, if you see one, remove the line that was added to your $HOME/.profile that sources the nix environment.