Add nix-on-droid script

default.nix

@@ -1,39 +1,5 @@
-# Licensed under GNU Lesser General Public License v3 or later, see COPYING.
-# Copyright (c) 2019 Alexander Sosedkin and other contributors, see AUTHORS.
-
-{ }:
-
-let
-  nixpkgs = import <nixpkgs> { };
-
-  pkgs = import ./src {
-    arch = if nixpkgs.stdenv.hostPlatform.isArm then "aarch64" else "i686";
-    initialBuild = false;
-  };
-in
+{ pkgs ? import <nixpkgs> { } }:
 
 {
-  # inherit (pkgs) proot-termux;
-
-  basic-environment = nixpkgs.buildEnv {
-    name = "basic-environment";
-
-    paths = [
-      nixpkgs.bashInteractive
-      nixpkgs.cacert
-      nixpkgs.coreutils
-      nixpkgs.less  # since nix tools really want a pager available, #27
-      nixpkgs.nix
-      # pkgs.proot-termux
-      pkgs.files.etc-group
-      pkgs.files.etc-passwd
-      pkgs.files.hm-install
-      pkgs.files.home-nix-default
-      pkgs.files.login
-      pkgs.files.login-inner
-      pkgs.files.nix-conf
-      pkgs.files.nix-on-droid-linker
-      pkgs.files.resolv-conf
-    ];
-  };
-} // pkgs.files
+  nix-on-droid = pkgs.callPackage ./nix-on-droid { };
+}

nix-on-droid/default.nix

@@ -0,0 +1,19 @@
+# Licensed under GNU Lesser General Public License v3 or later, see COPYING.
+# Copyright (c) 2019 Alexander Sosedkin and other contributors, see AUTHORS.
+
+{ bash, coreutils, nix, runCommand }:
+
+runCommand
+  "nix-on-droid"
+  {
+    preferLocalBuild = true;
+    allowSubstitutes = false;
+  }
+  ''
+    install -D -m755  ${./nix-on-droid.sh} $out/bin/nix-on-droid
+
+    substituteInPlace $out/bin/nix-on-droid \
+      --subst-var-by bash "${bash}" \
+      --subst-var-by coreutils "${coreutils}" \
+      --subst-var-by nix "${nix}"
+  ''

nix-on-droid/nix-on-droid.sh

@@ -0,0 +1,111 @@
+#!@bash@/bin/bash
+
+PATH=@coreutils@/bin:@nix@/bin:${PATH:+:}$PATH
+
+set -eu
+set -o pipefail
+
+function errorEcho() {
+    >&2 echo $@
+}
+
+function doHelp() {
+    echo "Usage: $0 [OPTION] COMMAND"
+    echo
+    echo "Options"
+    echo
+    echo "  -v|--verbose    Verbose output"
+    echo "  -n|--dry-run    Do a dry run, only prints what actions would be taken"
+    echo "  -h|--help       Print this help"
+    echo
+    echo "Options passed on to nix build"
+    echo
+    echo "  --cores NUM"
+    echo "  --keep-failed"
+    echo "  --keep-going"
+    echo "  --max-jobs NUM"
+    echo "  --option NAME VALUE"
+    echo "  --show-trace"
+    echo
+    echo "Commands"
+    echo
+    echo "  help            Print this help"
+    echo "  switch          Build and activate configuration"
+}
+
+function doSwitch() {
+    local profileDirectory="/nix/var/nix/profiles/nix-on-droid"
+
+    echo "Building activation package.."
+    nix build \
+        --no-link \
+        --file "<nix-on-droid/modules>" \
+        ${PASSTHROUGH_OPTS[*]} \
+        activationPackage
+
+    echo "Save profile activation package.."
+    generationDir="$(nix path-info --file "<nix-on-droid/modules>" activationPackage)"
+    nix-env --profile "${profileDirectory}" --set "${generationDir}"
+
+    echo "Run activation script.."
+    "${generationDir}/activate"
+}
+
+
+COMMAND=
+PASSTHROUGH_OPTS=()
+
+while [[ $# -gt 0 ]]; do
+    opt="$1"
+    shift
+    case $opt in
+        help|switch)
+            COMMAND="$opt"
+            ;;
+        -h|--help)
+            doHelp
+            exit 0
+            ;;
+        -n|--dry-run)
+            export DRY_RUN=1
+            ;;
+        --option)
+            PASSTHROUGH_OPTS+=("$opt" "$1" "$2")
+            shift 2
+            ;;
+        --max-jobs|--cores)
+            PASSTHROUGH_OPTS+=("$opt" "$1")
+            shift
+            ;;
+        --keep-failed|--keep-going|--show-trace)
+            PASSTHROUGH_OPTS+=("$opt")
+            ;;
+        -v|--verbose)
+            export VERBOSE=1
+            ;;
+        *)
+            errorEcho "$0: unknown option '$opt'"
+            errorEcho "Run '$0 --help' for usage help"
+            exit 1
+            ;;
+    esac
+done
+
+if [[ -z $COMMAND ]]; then
+    doHelp >&2
+    exit 1
+fi
+
+case $COMMAND in
+    switch)
+        doSwitch
+        ;;
+    help)
+        doHelp
+        ;;
+    *)
+        errorEcho "Unknown command: $COMMAND"
+        doHelp >&2
+        exit 1
+        ;;
+esac