Minor speed tweaks to entrypoint.

@@ -2,20 +2,22 @@
 
 set -e
 
-tool_uid="$(id -u tool)"
-tool_gid="$(id -g tool)"
+tool_uid=
+tool_gid=
 
 adjust_tool_uid_gid() {
 	declare usermod_args=() groupmod_args=()
 	declare -a new_groups=()
 
 	if [[ $MAP_UID ]]; then
-		[[ $(id -u tool) -ne $MAP_UID ]] && usermod_args+=(-u $MAP_UID)
+		[[ $tool_uid -ne $MAP_UID ]] && usermod_args+=(-u $MAP_UID)
+		tool_uid="$MAP_UID"
 	fi
 	if [[ $MAP_GROUPS ]]; then
 		set -- $MAP_GROUPS
 		if [[ $tool_gid -ne $1 ]]; then
 			groupmod_args=(-g "$1")
+			tool_gid="$1"
 		fi
 		shift
 		for group in "$@"; do
@@ -76,13 +78,14 @@ configure_cache() {
 	chown -h tool:tool "/home/tool/.cache"
 }
 
-# TODO: Save /run/user between calls
-mkdir -p /run/user/$tool_uid
+tool_uid="$(id -u tool)"
+tool_gid="$(id -g tool)"
 
 adjust_tool_uid_gid
 
-tool_uid="$(id -u tool)"
-tool_gid="$(id -g tool)"
+# TODO: Save /run/user between calls
+mkdir -p /run/user/$tool_uid
+
 run_state="/run/user/$tool_uid/inkluster-dev"
 
 if [[ ! -d $run_state ]]; then