Postfix manual - mysql_table(5)

    MYSQL_TABLE(5)                                                  MYSQL_TABLE(5)

    NAME
           mysql_table - Postfix MySQL client configuration

    SYNOPSIS
           postmap -q "string" mysql:/etc/postfix/filename

           postmap -q - mysql:/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 MySQL  databases.   In
           order  to use MySQL lookups, define a MySQL source as a lookup table in
           main.cf, for example:
               alias_maps = mysql:/etc/postfix/mysql-aliases.cf

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

    LIST MEMBERSHIP
           When  using  SQL  to  store  lists such as $mynetworks, $mydestination,
           $relay_domains, $local_recipient_maps, etc., it is important to  under-
           stand 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 $mydesti-
           nation 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.

    MYSQL 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).  Examples:
                      hosts = inet:host1.some.domain inet:host2.some.domain:port
                      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 con-
                  nections are automatically closed after being idle for  about  1
                  minute, and are re-opened as necessary. Postfix versions 2.0 and
                  earlier do not randomize the host order.

                  NOTE: if you specify localhost as a hostname (even if you prefix
                  it  with  inet:),  MySQL will connect to the default UNIX domain
                  socket.  In order to instruct MySQL to connect to localhost over
                  TCP you have to specify
                      hosts = 127.0.0.1

                  NOTE:  if  the  hosts  setting specifies one server, this client
                  assumes that the target is a load balancer  and  will  reconnect
                  immediately  after  a  single  failure,  instead  of failing all
                  requests temporarily. With older versions of this client,  spec-
                  ify the same server twice.

           user

           password
                  The  user name and password to log into the mysql server.  Exam-
                  ple:
                      user = someone
                      password = some_password

           dbname The database name on the servers. Example:
                      dbname = customer_database

           charset (default: utf8mb4)
                  The default MySQL client character set; this  also  implies  the
                  collation order.

                  This  parameter  is  available with Postfix 3.9 and later.  With
                  earlier Postfix versions, the default was chosen  by  the  MySQL
                  implementation (utf8mb4 as of MySQL 8.0, latin1 historically).

           idle_interval (default: 60)
                  The  number  of  seconds after which an idle database connection
                  will be closed.

                  This feature is available in Postfix 3.9 and later.

           retry_interval (default: 60)
                  The number of seconds that a database connection will be skipped
                  after an error.

                  NOTE:  if  the  hosts  setting specifies one server, this client
                  assumes that the target is a load balancer  and  will  reconnect
                  immediately  after  a  single  failure,  instead  of failing all
                  requests temporarily. With older versions of this client,  spec-
                  ify the same server twice.

                  This feature is available in Postfix 3.9 and later.

           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'

                  By  default,  every  query  must return a result set (instead of
                  storing its results in a table); with "require_result_set =  no"
                  (Postfix  3.2 and later), the absence of a result set is treated
                  as "not found".

                  This parameter supports the following '%' expansions:

                  %%     This is replaced by a literal '%' character.

                  %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 sup-
                         pressed 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.

                  %[1-9] The  patterns  %1,  %2, ... %9 are replaced by the corre-
                         sponding 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  sup-
                         pressed and returns no results.

                  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.

                  This parameter is available with Postfix 2.2. In prior  releases
                  the   SQL   query   was  built  from  the  separate  parameters:
                  select_field, table, where_field and additional_conditions.  The
                  mapping from the old parameters to the equivalent query is:

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

                  The  '%s'  in  the  WHERE  clause  expands to the escaped search
                  string.  With Postfix 2.2 these legacy parameters  are  used  if
                  the query parameter is not specified.

                  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  sup-
                  ports 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 "type:table"
                  databases. 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 MySQL 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.

           option_file
                  Read options from the given file instead of the  default  my.cnf
                  location.  This  reads  options  from the [client] option group,
                  optionally  followed  by  options  from  the  group  given  with
                  option_group.

                  This parameter is available with Postfix 2.11 and later.

           option_group (default: Postfix >=3.2: client, <= 3.1: empty)
                  Read  options  from  the  given group of the mysql options file,
                  after reading options from the [client] group.

                  Postfix 3.2 and later read [client]  option  group  settings  by
                  default.  To  disable  this  specify  no option_file and specify
                  "option_group =" (i.e. an empty value).

                  Postfix 3.1 and earlier don't read [client]  option  group  set-
                  tings  unless  a non-empty option_file or option_group value are
                  specified. To enable this, specify, for example, "option_group =
                  client".

                  This parameter is available with Postfix 2.11 and later.

           require_result_set (default: yes)
                  If  "yes",  require  that  every query returns a result set.  If
                  "no", treat the absence of a result set as "not found".

                  This parameter is available with Postfix 3.2 and later.

    TLS-RELATED SETTINGS
           See      https://dev.mysql.com/doc/c-api/en/mysql-options.html       or
           https://mariadb.com/kb/en/mysql_optionsv/ for details of the underlying
           MYSQL_OPT_SSL_* features.

           tls_cert_file
                  File containing client's X509 certificate.

                  This parameter is available with Postfix 2.11 and later.

           tls_key_file
                  File containing the private key corresponding to  tls_cert_file.

                  This parameter is available with Postfix 2.11 and later.

           tls_CAfile
                  File  containing  X509 certificates for all of the Certification
                  Authorities the client will recognize.   Takes  precedence  over
                  tls_CApath.

                  This parameter is available with Postfix 2.11 and later.

           tls_CApath
                  Directory  containing  X509 Certification Authority certificates
                  in separate individual files.

                  This parameter is available with Postfix 2.11 and later.

           tls_ciphers
                  The list of permissible ciphers for SSL encryption.

                  This parameter is available with Postfix 2.11 and later.

           tls_verify_cert (default: no)
                  Verify that the server's name matches the  common  name  in  the
                  certificate.

                  This parameter is available with Postfix 2.11 and later.

    USING MYSQL STORED PROCEDURES
           Postfix  3.2  and  later  support calling a stored procedure instead of
           using a SELECT statement in the query, e.g.

               query = CALL lookup('%s')

           The previously described '%' expansions can be used in the parameter(s)
           to the stored procedure.

           By  default, every stored procedure call must return a result set, i.e.
           every code path must execute a SELECT statement that returns  a  result
           set   (instead   of   storing   its   results   in   a   table).   With
           "require_result_set = no", the absence of a result set  is  treated  as
           "not found".

           A  stored  procedure  must  not  return multiple result sets.  That is,
           there must be no code path that  executes  multiple  SELECT  statements
           that return a result (instead of storing their results in a table).

           The  following  is  an example of a stored procedure returning a single
           result set:

           CREATE [DEFINER=`user`@`host`] PROCEDURE
           `lookup`(IN `param` VARCHAR(255))
               READS SQL DATA
               SQL SECURITY INVOKER
               BEGIN
                   select goto from alias where address=param;
               END

    OBSOLETE MAIN.CF PARAMETERS
           For compatibility with other Postfix lookup  tables,  MySQL  parameters
           can  also be defined in main.cf.  In order to do that, specify as MySQL
           source a name that doesn't begin with a slash  or  a  dot.   The  MySQL
           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 "mysql:mysqlname", the parameter
           "hosts" would be defined in main.cf as "mysqlname_hosts".

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

    OBSOLETE QUERY INTERFACE
           This section describes an interface that is deprecated  as  of  Postfix
           2.2.  It  is  replaced  by  the  more general query interface described
           above. If  the  query  parameter  is  defined,  the  legacy  parameters
           described  here  ignored.   Please  migrate to the new interface as the
           legacy interface may be removed in a future release.

           The following parameters can be used  to  fill  in  a  SELECT  template
           statement of the form:

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

           The specifier %s is replaced by the search string, 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.

           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 maintenance
           postconf(5), configuration parameters
           ldap_table(5), LDAP lookup tables
           pgsql_table(5), PostgreSQL lookup tables
           sqlite_table(5), SQLite lookup tables

    README FILES
           DATABASE_README, Postfix lookup table overview
           MYSQL_README, Postfix MYSQL client guide

    LICENSE
           The Secure Mailer license must be distributed with this software.

    HISTORY
           MySQL support was introduced with Postfix version 1.0.

    AUTHOR(S)
           Original implementation by:
           Scott Cotton, Joshua Marcus
           IC Group, Inc.

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

           Stored-procedure support by John Fawcett.

           Wietse Venema
           Google, Inc.
           111 8th Avenue
           New York, NY 10011, USA

                                                                    MYSQL_TABLE(5)