Daniel-Constantin Mierla

Edited by

Daniel-Constantin Mierla

Table of Contents

1. Admin Guide
1. Overview
2. Dependencies
2.1. Kamailio Modules
2.2. External Libraries or Applications
3. Parameters
3.1. server (str)
4. Functions
4.1. redis_cmd(srvname, command, replyid)

List of Examples

1.1. Set server parameter
1.2. redis_cmd usage

Chapter 1. Admin Guide

1. Overview

This module provides a connector to interact with REDIS NoSQL Database from configuration file. You can read more about REDIS at http://redis.io.

It can connect to many REDIS servers and store the results in different containers.

2. Dependencies

2.1. Kamailio Modules

The following modules must be loaded before this module:

  • none.

2.2. External Libraries or Applications

The following libraries or applications must be installed before running Kamailio with this module loaded:

  • hiredis - available at https://github.com/antirez/hiredis .

3. Parameters

3.1. server (str)

Specify the details to connect to REDIS server. It takes a list of attribute=value separated by semicolon, the attributes can be name, addr, port and db. Name is a generic identifier to be used with module functions. addr and port are the IP address and the port to connect to REDIS server. db is the DB number to use (defaults to 0 if not specified).

You can set this parameter many times, in case you want to connect to many REDIS servers, just give different attributes and use the specific server name when querying the REDIS instance.

Default value is NULL.

Example 1.1. Set server parameter

modparam("ndb_redis", "server", "name=srvN;addr=;port=6379;db=1")
modparam("ndb_redis", "server", "name=srvX;addr=;port=6379;db=4")

4. Functions

4.1.  redis_cmd(srvname, command, replyid)

Send a command to REDIS server identified by srvname. The reply will be stored in a local continer identified by replyid. All the parameters can be strings with pseudo-variables that are evaluated at runtime.

The reply can be accessed via pseudo-variable $redis(key). The key can be: type - type of the reply (as in hiredis.h); value - the value returned by REDIS server; info - in case of error from REDIS, it will contain an info message.

If reply type is an array (as in hiredis.h), there are other keys available:

  • size - returns number of elements in the array.

  • type[n] - returns the type of the nth element in the array. type - returns array type.

  • value[n] - returns value of the nth element. value - returns null for an array. You need to get each element by index.

Example 1.2. redis_cmd usage

if(redis_cmd("srvN", "INCR cnt", "r")) {
    # success - the incremented value is in $redis(r=>value)
    xlog("===== $redis(r=>type) * $redis(r=>value)\n");

# set a value
redis_cmd("srvN", "SET foo bar", "r");

redis_cmd("srvN", "SET ruri $ru", "r");

# get a value
redis_cmd("srvN", "GET foo", "r");

# array example
if(redis_cmd("srvN", "HMGET foo_key field1 field3", "r")) {
    xlog("array size: $redis(r=>size)\n");
    xlog("first values: $redis(r=>value[0]) , $redis(r=>value[1])\n");