# Import Handlers

Meridian supports a number of import handlers to facilitate provisioning nodes from an external system (foreign source) into a requisition. This is done in the `${OPENNMS_HOME}/etc/provisiond-configuration.xml` file by referencing a requisition’s location via a URL. Most commonly, these URLs are files on the file system (`file:${OPENNMS_HOME}/etc/imports/<my-requisition.xml>`) created through the Requisition UI. However, these same requisitions for adding, updating, and deleting nodes can also come from external URLs. For example, a requisition can be retrieved using the HTTP protocol.

In addition to the standard protocols supported by Java, we provide a series of custom URL handlers to help retrieve requisitions from external sources.

## Generic handler

The generic handler is made available using URLs of the form: `requisition://type?param=1;param=2`

Use these URLs to invoke handlers, both locally and via a Minion. In addition to the type-specific parameters, all handlers support the following parameters:

Table 1. Optional parameters
Parameter Description Default

location

The name of the location at which the handler should run.

Default

ttl

The maximum number of milliseconds to wait for the handler when run remotely.

20000

Use the `opennms:show-import` command, available via the Karaf shell, to show the results of an import without persisting or triggering the import:

``opennms:show-import -l MINION http url=http://127.0.0.1:8000/req.xml``

### Configuration

The configuration of the Provisioning system allows the definition of zero or more import requisitions, each with its own cron-based schedule. This allows for automatic importing from various sources intended for integration with external URLs such as HTTP and/or DNS protocol handler. A default configuration is provided in the Meridian `etc/` directory and is called: `provisiond-configuration.xml`. This default configuration has an example for scheduling an import from a DNS server running on the localhost requesting nodes from the zone, localhost and will be imported once per day at midnight. Not very practical, but is a good example to get you started.

``````<?xml version="1.0" encoding="UTF-8"?>
<provisiond-configuration xmlns="http://xmlns.opennms.org/xsd/config/provisiond-configuration"

foreign-source-dir="/opt/opennms/etc/foreign-sources"
requistion-dir="/opt/opennms/etc/imports"

importThreads="8" scanThreads="10" rescanThreads="10" writeThreads="8" >

<!--
http://www.quartz-scheduler.org/documentation/quartz-1.x/tutorials/crontrigger
Field Name     Allowed Values      Allowed Special Characters
Seconds        0-59                , - * /
Minutes        0-59                , - * /
Hours          0-23                , - * /
Day-of-month   1-31                , - * ? / L W C
Month          1-12 or JAN-DEC     , - * /
Day-of-Week    1-7 or SUN-SAT      , - * ? / L C #
Year (Opt)     empty, 1970-2099    , - * /
-->

<requisition-def import-name="localhost" import-url-resource="dns://localhost/localhost">
<cron-schedule>0 0 0 * * ? *</cron-schedule>
</requisition-def>
</provisiond-configuration>``````

## Configuration reload

It is possible to reload the provisiond configuration without having to restart Meridian by triggering the reloadDaemonConfig UEI:

``\${OPENNMS_HOME}/bin/send-event.pl uei.opennms.org/internal/reloadDaemonConfig --parm 'daemonName Provisiond'``