Add default.nix as entry point for nix-channel

default.nix

@@ -0,0 +1,53 @@
+{ pkgs ? import <nixpkgs> { } }:
+
+rec {
+  basic-environment = pkgs.buildEnv {
+    name = "basic-environment";
+
+    paths = with pkgs; [
+      bashInteractive
+      cacert
+      coreutils
+      hm-install
+      nix
+      nix-on-droid-linker
+    ];
+  };
+
+  hm-install = pkgs.writeScriptBin "hm-install" ''
+    #!/usr/bin/env sh
+    set -e
+
+    if [ -e $HOME/.nix-profile/etc/profile.d/hm-session-vars.sh ]; then
+      echo "You already have home-manager installed."
+    fi
+
+    echo "Subscribing to home-manager channel..."
+    ${pkgs.nix}/bin/nix-channel --add https://github.com/rycee/home-manager/archive/master.tar.gz home-manager
+    echo "Updating channels..."
+    ${pkgs.nix}/bin/nix-channel --update
+
+    export NIX_PATH=$HOME/.nix-defexpr/channels''${NIX_PATH:+:}$NIX_PATH
+
+    if [ ! -e $HOME/.config/nixpkgs/home.nix ]; then
+      echo "Creating an initial home-manager configuration in ~/.config/nixpkgs/home.nix ..."
+      ${pkgs.coreutils}/bin/mkdir -p $HOME/.config/nixpkgs
+      ${pkgs.coreutils}/bin/cp -n /etc/home.nix.default $HOME/.config/nixpkgs/home.nix
+    fi
+
+    echo "Uninstalling basic-environment..."
+    ${pkgs.nix}/bin/nix-env --uninstall basic-environment
+    echo "Installing home-manager..."
+    ${pkgs.nix}/bin/nix run nixpkgs.nix -c ${pkgs.nix}/bin/nix-shell '<home-manager>' -A install
+  '';
+
+  nix-on-droid-linker = pkgs.writeScriptBin "nix-on-droid-linker" ''
+    #!/usr/bin/env sh
+    set -e
+
+    echo "Linking ~/.nix-profile/bin/sh to /bin/sh"
+    ${pkgs.coreutils}/bin/ln -snf $HOME/.nix-profile/bin/sh /bin/sh
+    echo "Linking ~/.nix-profile/usr/bin/env to /usr/bin/env"
+    ${pkgs.coreutils}/bin/ln -snf $HOME/.nix-profile/bin/env /usr/bin/env
+  '';
+}