kamailio/modules/cfg_db

1. cfg_db module

Tomas Mandys

Iptel.org

Copyright � 2008 Tomas Mandys
Revision History
Revision $Revision$ $Date$
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1.1. Overview
1.2. Dependencies
1.3. Parameters

1.3.1. db_url (string)
1.3.2. transl_tbl (string) := "cfg_transl"
1.3.3. custom_tbl (string) := "cfg_custom"

1.4. Functions
1.5. Examples

1.1. Overview

The module implements a database driver for the configuration
parameters API. When configuration parameters are being declared
(typically when starting) API then driver is notified and has chance to
set value (of any parameter) based on value taken from database. It's
primarily targeted for interfacing with 3rd party software which is
aware of configuration.

Parameter is uniquely identified by group_name plus name, which is used
by the driver to check if a value can be found. Because configuration
parameters may be spread in many tables, a translation table is used to
indicate where to start searching. Multiple look-up tables may be
defined for single parameter, tables are searched in the first round by
exact match until parameter is found, all tables listed with wildcard
(asterisk) in group name are searched in the second round. If a
parameter is not found then its value is left unchanged.

Configuration parameters are normally declared in C code and this
module additionally supports also declaring custom parameters in extra
table. Such parameters may be used typically in script only. All
parameters listed in the table are declared in the first step, values
are initialized in the second step using the same procedure as C-code
parameters.

The module does not reflect changes made in parameters when SER is
running. It just declares variables and assigns values when SER is
starting. That's all.

1.2. Dependencies

A loaded database module.

1.3. Parameters

1.3.1. db_url (string)

Default database URL.

The format is:
db_url = database

Example 1. Example db_url
loadmodule("mysql.so");
loadmodule("cfg_db.so");
...
modparam("cfg_db", "db_url", "mysql://SER:[email protected]:12345/SER");
...

1.3.2. transl_tbl (string) := "cfg_transl"

Name of table used for pointing group_name+name into configuration
table. If empty/null field values are found then default values will be
used. The default values are declared in record having group_name
called . The C-code "absolutely" default values ("cfg_var",
"group_name", "name", "value"). The other keyword is asterisk * which
matches all parameters and will be used if parameter is not explicitely
mentioned.

1.3.3. custom_tbl (string) := "cfg_custom"

Name of table used for extra param declaration (group_name, name, type,
min/max value, description).

1.4. Functions

None.

1.5. Examples

Example 2. Content of tables
cfg_transl table:
group_name|name|cfg_table|cfg_table_group_name_field|cfg_table_name_fiel
d|cfg_table_value_field
core|use_dst_blacklist|cfg_dns|||
core|dst_blacklist_mem|cfg_dns|||
core|dst_blacklist_expire|||
my|route_addr|cfg_my|my_group_name|my_name|my_value ; overrides ault> values
my|use_rtp_proxy|cfg_my|my_group_name|my_name|my_value
*|*|||| ; matches all param ids, points to tables defined in row t>
||cfg_var|group_name|name|value ; default cfg_table* values

cfg_custom table:
group_name|name|value_type|min_value|max_value|description
my|route_addr|S|||Routing address
my|use_rtp_proxy|I|0|1|Use RTP proxy

cfg_var table:
group_name|my_name|value
core|debug|4

cfg_my table:
my_group_name|my_name|my_value
my|route_addr|127.0.0.1
my|use_rtp_proxy|1

cfg_dns table:
group_name|name|value
dns|use_dst_blacklist|1
dns|dst_blacklist_mem|1024
dns|dst_blacklist_expire|60