An expression will contain some directives wrapped in {} characters.

When using nodeattrib substitution there might be the temptation to do substition of username and passwords which will not work.

Example

when using noderun attribute expressions for bmcuser and bmcpass will not work, this is expected behavior.

noderun <nodename> ipmitool -I lanplus -U "{bmcuser}" -P {bmcpass} -H {bmc}

Password:
n1052: Error: Unable to establish IPMI v2 / RMCP+ session

The inability to use attribute expressions for passwords is expected behavior for security reasons. Allowing this functionality would allow passwords and username to be echoed in plane text