Simple wrapper to add packages declaratively

nix-install.sh

#!/usr/bin/env nix-shell
#!nix-shell -p jq -i bash

# Usage:
#
#   nix-install vim

set -e
registry=~/.config/nix/my_packages.json
profile=~/.config/nix/my_profile.nix
pkg="$1"
filter=".packages = (.packages + [\"$pkg\"] | unique)"

if [[ ! $(jq '.packages' "$registry") ]]; then
  echo "initializing registry at $registry"
  echo '{"packages": []}' > "$registry"
fi

# if [[ ! -f "$profile" ]]; then
#
echo "initializing profile $profile"
cat << NIX > "$profile"
{ pkgs ? import <nixpkgs> {}, name ? "simple-nix" }:
pkgs.buildEnv {
  inherit name;
  extraOutputsToInstall = ["out" "bin" "lib"];
  paths = map (name:
    let path = pkgs.lib.splitString "." name;
    in pkgs.lib.getAttrFromPath path pkgs
  ) (
    builtins.fromJSON (
      builtins.readFile ${registry}
    )
  ).packages;
}
NIX

# fi

echo "adding $pkg to $registry"

updated="$(jq "$filter" "$registry")"
echo "$updated" > "$registry"

nix-env --set -f "$profile" --argstr name "$(whoami)-user-env-$(date -I)"