Functions to set up the Nix environment variables for Elvish.
We use the re and util modules.
use re
use str
use github.com/zzamboni/elvish-modules/utilI have two environment setup functions, one for a multi-user environment (default on macOS) and the other for a single-user setup.
This is the default setup on macOS. This script was ported to Elvish from /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh.
fn multi-user-setup {
# Set up secure multi-user builds: non-root users build through the
# Nix daemon.
if (or (not-eq $E:USER root) (not ?(test -w /nix/var/nix/db))) {
set E:NIX_REMOTE = daemon
}
set E:NIX_USER_PROFILE_DIR = "/nix/var/nix/profiles/per-user/"$E:USER
var nix-profiles = [
"/nix/var/nix/profiles/default"
$E:HOME"/.nix-profile"
]
set E:NIX_PROFILES = (str:join " " $nix-profiles)
# Set up the per-user profile.
mkdir -m 0755 -p $E:NIX_USER_PROFILE_DIR
if (not ?(test -O $E:NIX_USER_PROFILE_DIR)) {
echo (styled "WARNING: bad ownership on "$E:NIX_USER_PROFILE_DIR yellow) >&2
}
if ?(test -w $E:HOME) {
if (not ?(test -L $E:HOME/.nix-profile)) {
if (not-eq $E:USER root) {
ln -s $E:NIX_USER_PROFILE_DIR/profile $E:HOME/.nix-profile
} else {
# Root installs in the system-wide profile by default.
ln -s /nix/var/nix/profiles/default $E:HOME/.nix-profile
}
}
# Subscribe the root user to the NixOS channel by default.
if (and (eq $E:USER root) (not ?(test -e $E:HOME/.nix-channels))) {
echo "https://nixos.org/channels/nixpkgs-unstable nixpkgs" > $E:HOME/.nix-channels
}
# Create the per-user garbage collector roots directory.
var nix-user-gcroots-dir = "/nix/var/nix/gcroots/per-user/"$E:USER
mkdir -m 0755 -p $nix-user-gcroots-dir
if (not ?(test -O $nix-user-gcroots-dir)) {
echo (styled "WARNING: bad ownership on "$nix-user-gcroots-dir yellow) >&2
}
# Set up a default Nix expression from which to install stuff.
if (or (not ?(test -e $E:HOME/.nix-defexpr)) ?(test -L $E:HOME/.nix-defexpr)) {
rm -f $E:HOME/.nix-defexpr
mkdir -p $E:HOME/.nix-defexpr
if (not-eq $E:USER root) {
ln -s /nix/var/nix/profiles/per-user/root/channels $E:HOME/.nix-defexpr/channels_root
}
}
}
set E:NIX_SSL_CERT_FILE = "/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"
set E:NIX_PATH = "/nix/var/nix/profiles/per-user/root/channels"
# E:MANPATH = ~/.nix-profile/share/man
set paths = [
~/.nix-profile/bin
~/.nix-profile/sbin
~/.nix-profile/lib/kde4/libexec
/nix/var/nix/profiles/default/bin
/nix/var/nix/profiles/default/sbin
/nix/var/nix/profiles/default/lib/kde4/libexec
$@paths
]
#echo (styled "Nix environment ready" green)
}This is not fully tested as I don’t use this setup - use with care!
fn single-user-setup {
# Set up single-user Nix (no daemon)
if (not-eq $E:HOME "") {
var nix-link = ~/.nix-profile
if (not ?(test -L $nix-link)) {
echo (styled "creating "$nix-link green) >&2
var -nix-def-link = /nix/var/nix/profiles/default
ln -s $-nix-def-link $nix-link
}
set paths = [
$nix-link"/bin"
$nix-link"/sbin"
$@paths
]
# Subscribe the user to the Nixpkgs channel by default.
if (not ?(test -e ~/.nix-channels)) {
echo "https://nixos.org/channels/nixpkgs-unstable nixpkgs" > ~/.nix-channels
}
# Append ~/.nix-defexpr/channels/nixpkgs to $NIX_PATH so that
# <nixpkgs> paths work when the user has fetched the Nixpkgs
# channel.
if (not-eq $E:NIX_PATH "") {
set E:NIX_PATH = $E:NIX_PATH":nixpkgs="$E:HOME"/.nix-defexpr/channels/nixpkgs"
} else {
set E:NIX_PATH = "nixpkgs="$E:HOME"/.nix-defexpr/channels/nixpkgs"
}
# Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
if ?(test -e /etc/ssl/certs/ca-certificates.crt ) { # NixOS, Ubuntu, Debian, Gentoo, Arch
set E:NIX_SSL_CERT_FILE = /etc/ssl/certs/ca-certificates.crt
} elif ?(test -e /etc/ssl/ca-bundle.pem ) { # openSUSE Tumbleweed
set E:NIX_SSL_CERT_FILE = /etc/ssl/ca-bundle.pem
} elif ?(test -e /etc/ssl/certs/ca-bundle.crt ) { # Old NixOS
set E:NIX_SSL_CERT_FILE = /etc/ssl/certs/ca-bundle.crt
} elif ?(test -e /etc/pki/tls/certs/ca-bundle.crt ) { # Fedora, CentOS
set E:NIX_SSL_CERT_FILE = /etc/pki/tls/certs/ca-bundle.crt
} elif ?(test -e $nix-link"/etc/ssl/certs/ca-bundle.crt" ) { # fall back to cacert in Nix profile
set E:NIX_SSL_CERT_FILE = $nix-link"/etc/ssl/certs/ca-bundle.crt"
} elif ?(test -e $nix-link"/etc/ca-bundle.crt" ) { # old cacert in Nix profile
set E:NIX_SSL_CERT_FILE = $nix-link"/etc/ca-bundle.crt"
}
}
}nix:search is a wrapper around nix-env -qa, which removes the automatic pager wrapper, and pipes through json_pp if the first argument is --json.
fn search {|@pkgs|
var pipecmd = cat
var opts = []
if (eq $pkgs[0] "--json") {
set pipecmd = json_pp
}
nix-env -qa $@opts $@pkgs | $pipecmd
}nix:install is a wrapper around nix-env -i.
fn install {|@pkgs|
nix-env -i $@pkgs
}nix:brew-to-nix is a simple interactive function to go through installed Homebrew packages and allow you to replace them with their Nix equivalents. Only loops through the “leaves” - i.e. Homebrew packages that do not have any dependents, so it will not loop through everything. You may need to run it a few times to fully clean up.
fn brew-to-nix {
brew leaves | each {|pkg|
echo (styled "Package "$pkg green)
brew info $pkg
var loop = $true
while $loop {
set loop = $false
print (styled $pkg": [R]emove/[Q]uery nix/[K]eep/Remove and [I]nstall with nix? " yellow)
var resp = (util:readline </dev/tty)
if (eq $resp "r") {
brew uninstall --force $pkg
} elif (eq $resp "q") {
set _ = ?(search --description '.*'$pkg'.*')
set loop = $true
} elif (eq $resp "i") {
install $pkg
brew uninstall --force $pkg
}
}
}
}nix:info is a wrapper to query nix packages, but showing more information than what nix-env usually provides, by extracting it from the package metadata.
fn info {|pkg|
# Get data
var install-path = nil
var installed = ?(set install-path = [(re:split '\s+' (nix-env -q --out-path $pkg 2>/dev/null))][1])
var flag = (if $installed { put "-q" } else { put "-qa" })
var data = (nix-env $flag --json $pkg | from-json)
var top-key = (keys $data | take 1)
set pkg = $data[$top-key]
var meta = $pkg[meta]
# Produce the output
print (styled $pkg[name] yellow)
if (has-key $meta description) {
echo ":" $meta[description]
} else {
echo ""
}
if (has-key $meta homepage) {
echo (styled "Homepage: " blue) $meta[homepage]
}
if $installed {
echo (styled "Installed:" green) $install-path
} else {
echo (styled "Not installed" red)
}
echo From: (re:replace ':\d+' "" $meta[position])
if (has-key $meta longDescription) {
echo ""
echo $meta[longDescription] | fmt
}
}