1 files changed, 46 insertions, 0 deletions
diff --git a/scripts/bigsur-nixbld-user-migration.sh b/scripts/bigsur-nixbld-user-migration.sh
new file mode 100755
index 000000000..f1619fd56
--- /dev/null
+++ b/scripts/bigsur-nixbld-user-migration.sh
@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+
+((NEW_NIX_FIRST_BUILD_UID=301))
+
+id_available(){
+	dscl . list /Users UniqueID | grep -E '\b'$1'\b' >/dev/null
+}
+
+change_nixbld_names_and_ids(){
+	local name uid next_id
+	((next_id=NEW_NIX_FIRST_BUILD_UID))
+	echo "Attempting to migrate nixbld users."
+	echo "Each user should change from nixbld# to _nixbld#"
+	echo "and their IDs relocated to $next_id+"
+	while read -r name uid; do
+		echo "   Checking $name (uid: $uid)"
+		# iterate for a clean ID
+		while id_available "$next_id"; do
+			((next_id++))
+			if ((next_id >= 400)); then
+				echo "We've hit UID 400 without placing all of your users :("
+				echo "You should use the commands in this script as a starting"
+				echo "point to review your UID-space and manually move the"
+				echo "remaining users (or delete them, if you don't need them)."
+				exit 1
+			fi
+		done
+
+		if [[ $name == _* ]]; then
+			echo "      It looks like $name has already been renamed--skipping."
+		else
+			# first 3 are cleanup, it's OK if they aren't here
+			sudo dscl . delete /Users/$name dsAttrTypeNative:_writers_passwd &>/dev/null || true
+			sudo dscl . change /Users/$name NFSHomeDirectory "/private/var/empty 1" "/var/empty" &>/dev/null || true
+			# remove existing user from group
+			sudo dseditgroup -o edit -t user -d $name nixbld || true
+			sudo dscl . change /Users/$name UniqueID $uid $next_id
+			sudo dscl . change /Users/$name RecordName $name _$name
+			# add renamed user to group
+			sudo dseditgroup -o edit -t user -a _$name nixbld
+			echo "      $name migrated to _$name (uid: $next_id)"
+		fi
+	done < <(dscl . list /Users UniqueID | grep nixbld | sort -n -k2)
+}
+
+change_nixbld_names_and_ids