{writeText}:
writeText "service-fns.sh" ''
  output() { cat $1/.outputs/$2; }
  output_path() { echo $(realpath $1/.outputs)/$2; }
  SERVICE_OUTPUTS=/run/services/outputs
  SERVICE_STATE=/run/services/state
  mkoutputs() {
    d=$SERVICE_OUTPUTS/$1
    mkdir -m 2751 -p $d && chown root:system $d
    echo $d
  }
  mkstate() {
    d=$SERVICE_STATE/$1
    mkdir -m 2751 -p $d && chown root:system $d
    echo $d
  }
  in_outputs() {
    cd `mkoutputs $1` && umask 0027
  }
''