mod_rest - HTTP interface to POST stanzas into ejabberd
Author: Nolan Eakins <sneakin@semanticgap.com>
Copyright (C) 2008 Nolan Eakins
Requirements: ejabberd trunk SVN 2025 (ejabberd 2.1.0, once released)
This is an ejabberd module that adds an HTTP handler that allows HTTP
clients to literally post arbitrary message stanzas to ejabberd. Those
stanzas then get shoved through ejabberd's router just like any other
stanza.
This module can also be used as a frontend to execute ejabberd commands.
CONFIGURATION
=============
To use this module, follow the general build instructions, and configure
in ejabberd.cfg as described.
Enable the module:
{modules,
[
{mod_rest, [ {allowed_ips, [ {127,0,0,1} ]} ]},
...
]
}.
And enable the HTTP request handler in the listen section:
{listen,
[
...
{5285, ejabberd_http, [
{request_handlers, [
{["rest"], mod_rest}
]}
]}
]
}.
With that configuration, you can send HTTP POST requests to the URL:
http://localhost:5285/rest
Configurable options:
allowed_ips: IP addresses that can use the rest service.
Allowed values: 'all' or a list of Erlang tuples.
Default value: all
Notice that the IP address is checked after the connection is established.
If you want to restrict the IP address that listens connections, and
only allow a certain IP to be able to connect to the port, then the
option allowed_ips is not useful to you: you better define the
listening IP address in the ejabberd listeners (see the ejabberd Guide).
allowed_destinations: Allowed destination Jabber ID addresses in the stanza.
Allowed values: 'all' or a list of strings.
Default value: all
allowed_stanza_types: Allowed stanza types of the posted stanza.
Allowed values: 'all' or a list of strings.
Default value: all
access_commands: Access restrictions to execute ejabberd commands.
This option is similar to the option ejabberdctl_access_commands that
is documented in the ejabberd Guide.
There is more information about AccessCommands in the ejabberd Guide.
Default value: []
Complex example configuration:
{modules,
[
{mod_rest, [
{allowed_ips, [ {127,0,0,1}, {192,168,1,12} ]},
{allowed_destinations, [ "nolan@localhost", "admin@example.com" ]},
{allowed_stanza_types, [ "message", "presence", "iq" ]},
{access_commands, [ {configure, [registered_users], []} ]}
]
},
...
]
}.
This module gives many power to perform tasks in ejabberd,
such power in bad hands can harm your server, so you should
restrict the IP address that can connect to the service using:
a firewall, allowed_ips option, or the listener IP option.
In ejabberd 2.0.x versions,
it is important that the value indicated in Content-Length matches
exactly the size of the content.
EXAMPLE REST CALL
=================
When the module receives this:
-------
POST /rest HTTP/1.1
Host: localhost
Content-Length: 85
<message to="nolan@localhost" from="localhost/rest"><body>World</body></message>
-------
ejabberd.log shows those messages:
-------
=INFO REPORT==== 2-Mar-2009::11:46:05 ===
I(<0.484.0>:ejabberd_listener:201) : (#Port<0.3661>) Accepted connection {{127,0,0,1},55945} -> {{127,0,0,1},5280}
=INFO REPORT==== 2-Mar-2009::11:46:05 ===
I(<0.251.0>:ejabberd_http:127) : started: {gen_tcp,#Port<0.3661>}
=INFO REPORT==== 2-Mar-2009::11:46:05 ===
I(<0.841.0>:mod_rest:81) : Got request from localhost/rest
with IP {{127,0,0,1},49613}
to nolan@localhost:
{xmlelement,"message",
[{"to","nolan@localhost"},{"from","localhost/rest"}],
[{xmlelement,"body",[],[{xmlcdata,<<"World">>}]}]}
-------
If the user nolan@localhost exists, he will receive this message:
-------
<message from='localhost/rest'
to='nolan@localhost'>
<body>World</body>
</message>
-------
Instead of an XMPP stanza, you can provide an ejabberd command to execute:
registered_users localhost
If you configure access_commands in mod_rest, you need to provide information
about a local Jabber account with enough privileges according to your option:
--auth robot localhost pass0011 registered_users localhost
EXAMPLE CALL WITH LYNX
======================
This example shows how to send a POST using Lynx:
$ lynx http://localhost:5280/rest/ -mime_header -post_data
<message to="nolan@localhost" from="localhost/rest"><body>World</body></message>
---
HTTP/1.0 200 OK
Connection: close
Content-Type: text/html; charset=utf-8
Content-Length: 2
Ok
EXAMPLE CALL WITH WGET
======================
This example shows how to send a POST using Wget:
$ wget http://localhost:5280/rest/ --server-response --post-data '<message to="nolan@localhost" from="localhost/rest"><body>World</body></message>'
--2009-03-02 12:01:42-- http://localhost:5280/rest/
Resolving localhost... 127.0.0.1
Connecting to localhost|127.0.0.1|:5280... connected.
HTTP request sent, awaiting response...
HTTP/1.0 200 OK
Connection: keep-alive
Content-Type: text/html; charset=utf-8
Content-Length: 2
Length: 2 [text/html]
Saving to: `index.html'
100%[======================================>] 2 --.-K/s in 0s
2009-03-02 12:01:42 (285 KB/s) - `index.html' saved [2/2]
The content of the index.html is simply:
Ok
Please notice that mod_rest and wget don't work correctly over HTTPS.
EXAMPLE AUTH COMMAND WITH WGET
==============================
To execute an ejabberd command, simply provide its name and arguments as in ejabberdctl:
wget http://localhost:5280/rest/ --server-response --post-data 'registered_users localhost'
If you configure access_commands option, you must provide the credentials like this:
wget http://localhost:5280/rest/ --server-response --post-data '--auth user1 localhost thepass registered_users localhost'
EXAMPLE CALL WITH PYTHON
========================
This example Python code first calls to send a stanza, and then calls to execute a command:
-------
import urllib2
server_url = 'http://localhost:5280/rest/'
call = '<message to="user1@localhost" from="localhost/rest"><body>World</body></message>'
resp = urllib2.urlopen(server_url, call)
result = resp.read()
print result
call = 'registered_users localhost'
resp = urllib2.urlopen(server_url, call)
result = resp.read()
print result
-------
EXAMPLE CALL WITH PHP
=====================
This example PHP code implements a call to execute a command (thanks to Qu1cksand):
-------
<?
function sendRESTRequest ($url, $request) {
// Create a stream context so that we can POST the REST request to $url
$context = stream_context_create (array ('http' => array ('method' => 'POST'
,'header' => "Host: localhost:5280\nContent-Type: text/html; charset=utf-8\nContent-Length: ".strlen($request)
,'content' => $request)));
// Use file_get_contents for PHP 5+ otherwise use fopen, fread, fclose
if (version_compare(PHP_VERSION, '5.0.0', '>=')) {
$result = file_get_contents($url, false, $context);
} else {
// This is the PHP4 workaround which is slightly less elegant
// Suppress fopen warnings, otherwise they interfere with the page headers
$fp = @fopen($url, 'r', false, $context);
$result = '';
// Only proceed if we have a file handle, otherwise we enter an infinite loop
if ($fp) {
while(!feof($fp)) {
$result .= fread($fp, 4096);
}
fclose($fp);
}
}
return $result;
}
$url = "http://localhost:5280/rest";
$request = "register user12 localhost somepass";
$response = sendRESTRequest($url, $request);
echo "Response: $response\n";
?>
-------
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