How to create a password file for the keystore

Question

I would like to run raiden manually on top of geth unfortunately this requires a password file for your keystore which you can find here on linux ```~/.ethereum/keystore````How do i create a password file for my keystore? this is what raiden requires

raiden /
--address $YOUR-ETHEREUM-ADDRESS / 
--keystore-path $PATH-TO-YOUR-KEYSTORE-FILE /
--password-file $PASSWORD-FILE-FOR-KEYSTORE-FILE /
--eth-rpc-endpoint $YOUR-ETHEREUM-NODE