Postfix manual - mysql_table(5)

    MYSQL_TABLE(5)                                                  MYSQL_TABLE(5)

    NAME
           mysql_table - Postfix MySQL/MariaDB 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 lmdb:, cdb:, hash:,  or  dbm:
           format.

           Alternatively,  lookup  tables can be specified as MySQL databases.  To
           find out what types of lookup tables your Postfix system  supports  use
           the "postconf -m" command.

           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.

           Even  though  the  component  name is 'mysql' in Postfix, MariaDB/MySQL
           client and servers can be used  interchangeably  as  the  functionality
           Postfix  relies  on is available in both. However, their code bases may
           still diverge in the future.

    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  only  one  server,  this
                  client  assumes  that  the  target  is  a load balancer and will
                  reconnect immediately after a single failure. With Postfix  ver-
                  sions 3.9 and earlier, specify 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  only one server, this
                  client assumes that the target  is  a  load  balancer  and  will
                  reconnect  immediately after a single failure. With Postfix ver-
                  sions 3.9 and earlier, specify 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)