Ubuntu Manpage: makeuserdb - create /etc/courier/userdb

Provided by: courier-authlib-userdb_0.71.4-1_amd64

NAME

       makeuserdb - create /etc/courier/userdb

SYNOPSIS

       makeuserdb [-f filename]

       pw2userdb

       vchkpw2userdb [--vpopmailhome=dir] [--todir=dir]

DESCRIPTION

makeuserdb creates /etc/courier/userdb.dat from the contents of /etc/courier/userdb.
/etc/courier/userdb's contents are described later in this document. Maildrop, Courier,
and other applications use /etc/courier/userdb.dat as a substitute/complement for your
system password file. The usual purpose for /etc/courier/userdb.dat is to specify
"virtual" accounts - accounts that do not have an associated system login. Usually (but
not necessarily) all virtual accounts share the same system userid.
/etc/courier/userdb.dat may also replace your system password file. Because the system
password file is a text file, when there's a large number of accounts it will be
significantly faster to search @userdb.dat@, which is a binary database, instead of a flat
text file that the system password file usually is.

The makeuserdb command can be safely executed during normal system activity.

The -f option creates filename.dat from filename, instead of the default
/etc/courier/userdb.dat from /etc/courier/userdb.

Format of /etc/courier/userdb
/etc/courier/userdb is a plain text file that can be created using any text editor. Blank
lines are ignored. Lines that start with the # character are comments, and are also
ignored. Other lines define properties of a single "account", one line per account.
/etc/courier/userdb may be a directory instead of a plain file. In that case all files in
/etc/courier/userdb are essentially concatenated, and are treated as a single file. Each
line takes the following format:

name<TAB>field=value|field=value...

name is the account name. name MUST contain only lowercase characters If Courier is
configured to treat lowercase and uppercase account names as identical, name is followed
by exactly one tab character, then a list of field/value pairs separated by vertical
slashes. field is the name of the field, value is the field value. Fields and values
themself cannot contain slashes or control characters. Fields may be specified in any
order. Here are all the currently defined fields. Note that not every field is used by
every application that reads /etc/courier/userdb.dat.

uid - value is a (possibly) unique numerical user ID for this account.

gid - value is a (possibly) unique numerical group ID for this account.

home - value is the account's home directory.

shell - value is the account's default login shell.

systempw - value is the account's password. See userdbpw(8)[1] for details on how to set
up this field.

pop3pw, esmtppw, imappw... - value specifies a separate password used only for
authenticating access using a specific service, such as POP3, IMAP, or anything else. If
not defined, systempw is always used. This allows access to an account to be restricted
only to certain services, such as POP3, even if other services are also enabled on the
server.

mail - value specifies the location of the account's Maildir mailbox. This is an optional
field that is normally used when userdb is used to provide aliases for other mail
accounts. For example, one particular multi-domain E-mail service configuration that's
used by both Qmail and Courier servers is to deliver mail for a mailbox in a virtual
domain, such as "user@example.com", to a local mailbox called "example-user". Instead of
requiring the E-mail account holder to log in as "example-user" to download mail from this
account, a userdb entry for "user@example.com" is set up with mail set to the location of
example-user's Maildir mailbox, thus hiding the internal mail configuration from the
E-mail account holder's view.

quota - value specifies the maildir quota for the account's Maildir. This has nothing to
do with actual filesystem quotas. Courier has a software-based Maildir quota enforcement
mechanism which requires additional setup and configuration. See maildirquota(7)[2] for
additional information.

/etc/courier/userdbshadow.dat
All fields whose name ends with 'pw' will NOT copied to /etc/courier/userdb.dat. These
fields will be copied to /etc/courier/userdbshadow.dat. makeuserdb creates
/etc/courier/userdbshadow.dat without any group and world permissions. Note that
makeuserdb reports an error if /etc/courier/userdb has any group or world permissions.

CONVERTING /etc/passwd and vpopmail to /etc/courier/userdb format
pw2userdb reads the /etc/passwd and /etc/shadow files and converts all entries to the
/etc/courier/userdb format, printing the result on standard output. The output of
pw2userdb can be saved as /etc/courier/userdb (or as some file in this subdirectory).
Linear searches of /etc/passwd can be very slow when you have tens of thousands of
accounts. Programs like maildrop always look in /etc/courier/userdb first. By saving the
system password file in /etc/courier/userdb it is possible to significantly reduce the
amount of time it takes to look up this information.

After saving the output of pw2userdb, you must still run makeuserdb to create
/etc/courier/userdb.dat.

vchkpw2userdb converts a vpopmail-style directory hierarchy to the /etc/courier/userdb
format. This is an external virtual domain management package that's often used with Qmail
servers.

Generally, an account named 'vpopmail' is reserved for this purpose. In that account the
file users/vpasswd has the same layout as /etc/passwd, and performs a similar function,
except that all userid in users/vpasswd have the same userid. Additionally, the domains
subdirectory stores virtual accounts for multiple domains. For example,
domains/example.com/vpasswd has the passwd file for the domain example.com. Some systems
also have a soft link, domains/default, that points to a domain that's considered a
"default" domain.

The vchkpw2userdb reads all this information, and tries to convert it into the
/etc/courier/userdb format. The --vpopmailhost option specifies the top level directory,
if it is not the home directory of the vpopmail account.

The vchkpw2userdb script prints the results on standard output. If specified, the --todir
option tries to convert all vpasswd files one at a time, saving each one individually in
dir. For example:

mkdir /etc/courier/userdb
vchkpw2userdb --todir=/etc/courier/userdb/vpopmail
makeuserdb

It is still necessary to run makeuserdb, of course, to create the binary database file
/etc/courier/userdb.dat

NOTE: You are still required to create the /etc/courier/userdb entry which maps system
userids back to accounts, "uid=<TAB>name", if that's applicable. vchkpw2userdb will not
do it for you.

NOTE: makeuserdb may complain about duplicate entries, if your "default" entries in
users/vpasswd or domains/default/vpasswd are the same as anything in any other
/etc/courier/userdb file. It is also likely that you'll end up with duplicate, but
distinct, entries for every account in the default domain. For example, if your default
domain is example.com, you'll end up with duplicate entries - you'll have entries for both
user and user@example.com.

If you intend to maintain the master set of accounts using vchkpw/vpopmail, in order to
avoid cleaning this up every time, you might want to consider doing the following: run
vchkpw2userdb once, using the --todir option. Then, go into the resulting directory, and
replace one of the redundant files with a soft link to /dev/null. This allows you to run
vchkpw2userdb without having to go in and cleaning up again, afterwards.

FILES

           /etc/courier/userdb
           /etc/courier/userdb.dat
           /etc/courier/userdbshadow.dat
           /etc/courier/userdb.tmp - temporary file
           /etc/courier/userdbshadow.tmp - temporary file

BUGS

       makeuserdb is a Perl script, and uses Perl's portable locking. Perl's documentation notes
       that certain combinations of locking options may not work with some networks.

NOTES