Andreas wrote:

...

I tried the userdb prefetch / postlogin script method to do some password manipulation, but it doesn't appear to work for me. In particular, I don't think this method works with

userdb { driver = passwd-file args = /path/to/passwd-file userdb_pw=%w }

From what i understand you have to set a userdb_<something> variable with passdb and userdb prefetch set. The %w variable seems to be already empty (again?) at userdb stage.

Did all of that. The problem is not prefetching, but that you can't pass arguments via the args=.... Dovecot parses the entire line as a password file pathname.

Timo Sirainen definitively writes:

With v2.1 try:

userdb { driver = passwd-file args = /path/to/passwd-file default_fields = pw=%w }

Thanks, Timo. This works beautifully. Furthermore, it doesn't need the userdb prefetch. Summarizing, the minimal incantation for passing dovecot variables to the post-login script is

userdb {
	driver = passwd-file
	args = /var/dovecot/test/passwd
	default_fields = pw=%w
}

service imap {
	executable = imap postlogin
	...
}

service pop3 {
	executable = imap postlogin
	...
}

service postlogin {
	executable = script-login /path/to/postlogin-exec
	# Careful -- defaults to root
	user = $default_internal_user
	unix_listener postlogin {
	}
}

I've updated the Dovecot2 wiki, but I am unsure which userdb's "default_fields" applies to, and whether it just applies to postlogin scripts, so I documented it at

http://wiki2.dovecot.org/AuthDatabase/PasswdFile

Joseph Tam jtam.home@gmail.com