# &adminguide;

## Overview

This module provides a non-db connector to interact with MongoDB NoSQL server from configuration file. You can read more about MongoDB at http://www.mongodb.org.

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

## Dependencies

### &kamailio; Modules

The following modules must be loaded before this module:

- none.

### External Libraries or Applications

The following libraries or applications must be installed before running &kamailio; with this module loaded:

- mongo-c-driver - available at https://github.com/mongodb/mongo-c-driver

  Note: if you use tls module, use at least mongo-c-driver v1.3.5 and compile the library by configuring it without automatic init and cleanup (you have to run: './configure --disable-automatic-init-and-cleanup') -- this option is planned to be removed in future versions. An alternative for v1.3.5 could be the patch from: https://github.com/miconda/mongo-c-driver/commit/51d95009de39eaeca48491682a5ffec4f83cde55

## Parameters

### `server` (str)

Specify the details to connect to MongoDB server. It takes a list of attribute=value separated by semicolon, the attributes can be name and uri. Name is a generic identifier to be used with module functions. The uri parameter must be a valid MongoDB database connection string.

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

Default value is NULL.

#### Set `server` parameter

    ...
    modparam("ndb_mongodb", "server", "name=mgs1;uri='mongodb://localhost/kamailio'")
    modparam("ndb_mongodb", "server", "name=mgs2;uri='mongodb://127.0.0.2/kamailio'")
    ...

## Functions

### `mongodb_cmd(srvname, dbname, cname, command, replyid)`

Send a valid command to MongoDB server identified by srvname. The reply will be stored in a local container 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 $mongodb(key). The key can be: type - type of the reply; value - the value in JSON format returned by MongoDB server; info - in case of error from MongoDB, it will contain an info message.

The result can contain many documents, see mongodb_next() function for more details.

Meaning of the parameters:

- srvname - MongoDB server name as given via 'server' parameter.

- dbname - MongoDB database name.

- cname - MongoDB collection (table) name.

- command - valid MongoDB command given as JSON string.

- replyid - the name of the container to store the response.

The function can be used from ANY_ROUTE.

#### `mongodb_cmd` usage

    ...
    if(mongodb_cmd("mgs1", "kamailio", "acc", "{ \"collStats\": \"acc\" }", "mgr1")) {
    	xlog("response from mongodb is [[$mongodb(mgr1=>value)]]\n");
    }
    ...

### `mongodb_cmd_simple(srvname, dbname, cname, command, replyid)`

Send a valid command to MongoDB server identified by srvname. The reply will be stored in a local container 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 $mongodb(key). The key can be: type - type of the reply; value - the value in JSON format returned by MongoDB server; info - in case of error from MongoDB, it will contain an info message.

This function should be used when the response has only one document.

See mongodb_cmd() for the meaning of the parameters.

The function can be used from ANY_ROUTE.

#### `mongodb_cmd_simple` usage

    ...
    if(mongodb_cmd_simple("mgs1", "kamailio", "acc", "{ \"collStats\": \"acc\" }", "mgr1")) {
    	xlog("response from mongodb is [[$mongodb(mgr1=>value)]]\n");
    }
    ...

### `mongodb_find(srvname, dbname, cname, command, replyid)`

Send a find command to MongoDB server identified by srvname. The reply will be stored in a local container 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 $mongodb(key). The key can be: type - type of the reply; value - the value in JSON format returned by MongoDB server; info - in case of error from MongoDB, it will contain an info message.

This function is useful for querying collections and accessing the results.

See mongodb_cmd() for the meaning of the parameters, with the remark that command has to be a valid filter JSON document, like for find() command in mongoc command line client tool.

The function can be used from ANY_ROUTE.

#### `mongodb_find` usage

    ...
    if(mongodb_find("mgs1", "kamailio", "acc", "{ \"src_user\" : \"111\" }", "mgr1")) {
    	xlog("response from mongodb is [[$mongodb(mgr1=>value)]]\n");
    }
    ...

### `mongodb_find_one(srvname, dbname, cname, command, replyid)`

Similar to mongodb_find(...), but it stops searching after first match, returning the result with one object - faster when expecting to have a single match. Parameters and behaviour are the same as for mongodb_find(...).

The function can be used from ANY_ROUTE.

#### `mongodb_find_one` usage

    ...
    if(mongodb_find_one("mgs1", "kamailio", "subscriber", "{ \"username\" : \"111\" }", "mgr1")) {
    	xlog("response from mongodb is [[$mongodb(mgr1=>value)]]\n");
    }
    ...

### `mongodb_next(replyid)`

Moves to next document in a MongoDB reply. This function can be used after a successful mongodb_cmd() or mongodb_find(). It returns true if there is a shift to document. The current document becomes available via $mongodb(key) variable.

#### `mongodb_next` usage

    ...
    if(mongodb_find("mgs1", "kamailio", "acc", "{ \"src_user\" : \"111\" }", "mgr1")) {
        xlog("first response from mongodb is [[$mongodb(mgr1=>value)]]\n");
        while(mongodb_next("mgr1") ){
            xlog("next response from mongodb is [[$mongodb(mgr1=>value)]]\n");
        }
    }
    mongodb_free("mgr1");
    ...

### `mongodb_free(replyid)`

Frees data in a previous reply from memory. After this function call, accessing to a freed replyid returns null value.

It is not really necessary to free a reply to use it again in a new mongodb_cmd function, being automatically freed on next command execution, but for freeing used resources (e.g., memory), it is recommended to do it.

#### `mongodb_free` usage

    ...
    if(mongodb_cmd_simple("mgs1", "kamailio", "acc", "{ \"collStats\": \"acc\" }", "mgr1")) {
    	xlog("response from mongodb is [[$mongodb(mgr1=>value)]]\n");
    }
    mongodb_free("mgr1");
    ...