pgsql_table (5)

Contents

NAME
SYNOPSIS
DESCRIPTION
BACKWARDS COMPATIBILITY
LIST MEMBERSHIP
PGSQL PARAMETERS
OBSOLETE QUERY INTERFACES
SEE ALSO
README FILES
LICENSE
HISTORY
AUTHOR(S)

NAME

pgsql_table - Postfix PostgreSQL client configuration

SYNOPSIS

postmap -q "string" pgsql:/etc/postfix/filename

postmap -q - pgsql:/etc/postfix/filename <inputfile

DESCRIPTION

The Postfix mail system uses optional tables for address rewriting or mail routing. These tables are usually in dbm or db format.

Alternatively, lookup tables can be specified as PostgreSQL databases. In order to use PostgreSQL lookups, define a PostgreSQL source as a lookup table in main.cf, for example: 

    alias_maps = pgsql:/etc/pgsql-aliases.cf

The file /etc/postfix/pgsql-aliases.cf has the same format as the Postfix main.cf file, and can specify the parameters described below.

BACKWARDS COMPATIBILITY



For compatibility with other Postfix lookup tables, PostgreSQL
parameters can also be defined in main.cf.  In order to do
that, specify as PostgreSQL source a name that doesn't begin
with a slash or a dot.  The PostgreSQL parameters will then
be accessible as the name you've given the source in its
definition, an underscore, and the name of the parameter.  For
example, if the map is specified as "pgsql:pgsqlname",
the parameter "hosts" below would be defined in main.cf as
"pgsqlname_hosts".


Note: with this form, the passwords for the PostgreSQL sources
are written in main.cf, which is normally world-readable.
Support for this form will be removed in a future Postfix
version.


Normally, the SQL query is specified via a single query
parameter (described in more detail below).  When this
parameter is not specified in the map definition, Postfix
reverts to an older interface, with the  SQL  query
constructed  from the select_function, select_field,
table, where_field and additional_conditions
parameters.  The old interface will be gradually phased
out. To migrate to the new interface set:



    query = SELECT select_function('%s')





or in the absence of select_function, the lower precedence:



    query = SELECT select_field
        FROM table
        WHERE where_field = '%s'
            additional_conditions





Use the value, not the name, of each legacy parameter. Note
that the additional_conditions parameter is optional
and if not empty, will always start with AND.


LIST MEMBERSHIP






When using SQL to store lists such as $mynetworks,
$mydestination, $relay_domains, $local_recipient_maps,
etc., it is important to understand that the table must
store each list member as a separate key. The table lookup
verifies the *existence* of the key. See "Postfix lists
versus tables" in the DATABASE_README document for a
discussion.


Do NOT create tables that return the full list of domains
in $mydestination or $relay_domains etc., or IP addresses
in $mynetworks.


DO create tables with each matching item as a key and with
an arbitrary value. With SQL databases it is not uncommon to
return the key itself or a constant value.


PGSQL PARAMETERS









hosts

The hosts that Postfix will try to connect to and query from.
Specify unix: for UNIX-domain sockets, inet: for TCP
connections (default).  Example:

    hosts = host1.some.domain host2.some.domain:port
    hosts = unix:/file/name





The hosts are tried in random order, with all connections over
UNIX domain sockets being tried before those over TCP.  The
connections are automatically closed after being idle for about
1 minute, and are re-opened as necessary.


NOTE: the unix: and inet: prefixes are accepted for
backwards compatibility reasons, but are actually ignored.
The PostgreSQL client library will always try to connect to an
UNIX socket if the name starts with a slash, and will try a TCP
connection otherwise.

user, password

The user name and password to log into the pgsql server.
Example:

    user = someone
    password = some_password




dbname

The database name on the servers. Example:

    dbname = customer_database




query

The SQL query template used to search the database, where %s
is a substitute for the address Postfix is trying to resolve,
e.g.

    query = SELECT replacement FROM aliases WHERE mailbox = '%s'





This parameter supports the following '%' expansions:





%%

This is replaced by a literal '%' character. (Postfix 2.2 and later)

%s

This is replaced by the input key.
SQL quoting is used to make sure that the input key does not
add unexpected metacharacters.

%u

When the input key is an address of the form user@domain, %u
is replaced by the SQL quoted local part of the address.
Otherwise, %u is replaced by the entire search string.
If the localpart is empty, the query is suppressed and returns
no results.

%d

When the input key is an address of the form user@domain, %d
is replaced by the SQL quoted domain part of the address.
Otherwise, the query is suppressed and returns no results.

%[SUD]

The upper-case equivalents of the above expansions behave in the
query parameter identically to their lower-case counter-parts.
With the result_format parameter (see below), they expand the
input key rather than the result value.


The above %S, %U and %D expansions are available with Postfix 2.2
and later

%[1-9]

The patterns %1, %2, ... %9 are replaced by the corresponding
most significant component of the input key's domain. If the
input key is user@mail.example.com, then %1 is com,
%2 is example and %3 is mail. If the input key is
unqualified or does not have enough domain components to satisfy
all the specified patterns, the query is suppressed and returns
no results.


The above %1, ... %9 expansions are available with Postfix 2.2
and later







The domain parameter described below limits the input
keys to addresses in matching domains. When the domain
parameter is non-empty, SQL queries for unqualified addresses
or addresses in non-matching domains are suppressed
and return no results.


The precedence of this parameter has changed with Postfix 2.2,
in prior releases the precedence was, from highest to lowest,
select_function, query, select_field, ...


With Postfix 2.2 the query parameter has highest precedence,
see COMPATIBILITY above.


NOTE: DO NOT put quotes around the query parameter.

result_format (default: %s)

Format template applied to result attributes. Most commonly used
to append (or prepend) text to the result. This parameter supports
the following '%' expansions:





%%

This is replaced by a literal '%' character.

%s

This is replaced by the value of the result attribute. When
result is empty it is skipped.

%u

When the result attribute value is an address of the form
user@domain, %u is replaced by the local part of the
address. When the result has an empty localpart it is skipped.

%d

When a result attribute value is an address of the form
user@domain, %d is replaced by the domain part of
the attribute value. When the result is unqualified it
is skipped.

%[SUD1-9]

The upper-case and decimal digit expansions interpolate
the parts of the input key rather than the result. Their
behavior is identical to that described with query,
and in fact because the input key is known in advance, queries
whose key does not contain all the information specified in
the result template are suppressed and return no results.







For example, using "result_format = smtp:[%s]" allows one
to use a mailHost attribute as the basis of a transport(5)
table. After applying the result format, multiple values
are concatenated as comma separated strings. The expansion_limit
and parameter explained below allows one to restrict the number
of values in the result, which is especially useful for maps that
must return at most one value.


The default value %s specifies that each result value should
be used as is.


This parameter is available with Postfix 2.2 and later.


NOTE: DO NOT put quotes around the result format!

domain (default: no domain list)

This is a list of domain names, paths to files, or
dictionaries. When specified, only fully qualified search
keys with a *non-empty* localpart and a matching domain
are eligible for lookup: 'user' lookups, bare domain lookups
and "@domain" lookups are not performed. This can significantly
reduce the query load on the PostgreSQL server.

    domain = postfix.org, hash:/etc/postfix/searchdomains





It is best not to use SQL to store the domains eligible
for SQL lookups.


This parameter is available with Postfix 2.2 and later.


NOTE: DO NOT define this parameter for local(8) aliases,
because the input keys are always unqualified.

expansion_limit (default: 0)

A limit on the total number of result elements returned
(as a comma separated list) by a lookup against the map.
A setting of zero disables the limit. Lookups fail with a
temporary error if the limit is exceeded.  Setting the
limit to 1 ensures that lookups do not return multiple
values.




OBSOLETE QUERY INTERFACES






This section describes query interfaces that are deprecated
as of Postfix 2.2.  Please migrate to the new query
interface as the old interfaces are slated to be phased
out.



select_function

This parameter specifies a database function name. Example:

    select_function = my_lookup_user_alias





This is equivalent to:

    query = SELECT my_lookup_user_alias('%s')





This parameter overrides the legacy table-related fields (described
below). With Postfix versions prior to 2.2, it also overrides the
query parameter. Starting with Postfix 2.2, the query
parameter has highest precedence, and the select_function
parameter is deprecated.





The following parameters (with lower precedence than the
select_function interface described above) can be used to
build the SQL select statement as follows:



    SELECT [select_field]
    FROM [table]
    WHERE [where_field] = '%s'
          [additional_conditions]





The specifier %s is replaced with each lookup by the lookup key
and is escaped so if it contains single quotes or other odd
characters, it will not cause a parse error, or worse, a security
problem.


Starting with Postfix 2.2, this interface is obsoleted by the more
general query interface described above. If higher precedence
the query or select_function parameters described above
are defined, the parameters described here are ignored.



select_field

The SQL "select" parameter. Example:

    select_field = forw_addr




table

The SQL "select .. from" table name. Example:

    table = mxaliases




where_field

The SQL "select .. where" parameter. Example:

    where_field = alias




additional_conditions

Additional conditions to the SQL query. Example:

    additional_conditions = AND status = 'paid'







SEE ALSO




postmap(1), Postfix lookup table manager
postconf(5), configuration parameters
ldap_table(5), LDAP lookup tables
mysql_table(5), MySQL lookup tables
sqlite_table(5), SQLite lookup tables



README FILES






Use "postconf readme_directory" or
"postconf html_directory" to locate this information.


DATABASE_README, Postfix lookup table overview
PGSQL_README, Postfix PostgreSQL client guide



LICENSE






The Secure Mailer license must be distributed with this software.


HISTORY




PgSQL support was introduced with Postfix version 2.1.



AUTHOR(S)




Based on the MySQL client by:
Scott Cotton, Joshua Marcus
IC Group, Inc.

Ported to PostgreSQL by:
Aaron Sethman

Further enhanced by:
Liviu Daia
Institute of Mathematics of the Romanian Academy
P.O. BOX 1-764
RO-014700 Bucharest, ROMANIA