ops/nixos: add assimilate.sh script

ops/nixos/assimilate.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+
+set -eu
+
+if [ $EUID -ne 0 ]; then
+	exec sudo "$0" "$@"
+fi
+
+if [ $# -lt 1 ]; then
+	echo "Usage: $0 hostname" >&2
+	exit 1
+fi
+
+depot_parent() {
+	pd="$(readlink -f "$1")/"
+	if [ "${pd#*/depot/}" = "$pd" ]; then
+		return
+	fi
+	pd="$(readlink -f "${pd%/depot/*}/depot")"
+	echo "$pd"
+}
+
+depot_path() {
+	pd="$(depot_parent "$PWD")"
+	if [ "$pd" = "" ]; then
+		pd="$(depot_parent "$(readlink -f "$0")")"
+	fi
+	echo "$pd"
+}
+
+readonly targethostname="$1"
+readonly depot="$(depot_path)"
+if [ "$depot" = "" ]; then
+	echo "This script needs to be executed in-depot (or the script itself should be in-depot)."
+	exit 1
+fi
+readonly system="$(nix-build -E '(import "'"$(depot_path)"'" {}).ops.nixos.'"${targethostname}" --no-out-link)"
+nix-env -p /nix/var/nix/profiles/system --set "$system"
+"$system/bin/switch-to-configuration" switch