rest_client Module

The following modules must be loaded before this module:

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

The maximum allowed time for any HTTP(S) transfer to complete. This interval is inclusive of the initial connect time window, hence the value of this parameter must be greater than or equal to connection_timeout.

Default value is “20” seconds.

...
modparam("rest_client", "curl_timeout", 10)
...

The maximum allowed time to establish a connection with the server.

Default value is “20” seconds.

...
modparam("rest_client", "connection_timeout", 4)
...

Allows complete control over how quickly we want to detect libcurl's completed TCP/TLS handshakes, so the transfers can be started. A lower "connect_poll_interval" will speed up all HTTP transfers, but will also increase CPU usage.

Default value is “20” milliseconds.

...
modparam("rest_client", "connect_poll_interval", 2)
...

Maximum number of asynchronous HTTP transfers a single OpenSIPS worker is allowed to run simultanously. As long as this threshold is reached for a worker, all new async transfers it attempts to perform will be done in a blocking manner, with appropriate logging warnings.

Default value is “100”.

...
modparam("rest_client", "max_async_transfers", 300)
...

Set this to 0 in order to disable the verification of the remote peer's certificate. Verification is done using a default bundle of CA certificates which come with libcurl.

Default value is “1” (enabled).

...
modparam("rest_client", "ssl_verifypeer", 0)
...

Set this to 0 in order to disable the verification that the remote peer actually corresponds to the server listed in the certificate.

Default value is “1” (enabled).

...
modparam("rest_client", "ssl_verifyhost", 0)
...

An optional path for CA certificates to be used for host verifications.

...
modparam("rest_client", "ssl_capath", "/home/opensips/ca_certificates")
...

Issues an HTTP GET request to the given 'url', and returns a representation of the resource.

The body_pv pseudo-var will hold the body of the HTTP response.

The optional ctype_pv pseudo-var will contain the value of the "Content-Type:" header.

The optional retcode_pv pseudo-var is used to retain the HTTP status code of the response message. Since the module is based on libcurl, a 0 value means no HTTP reply arrived at all.

Possible parameter types

This function can be used from the startup, branch, failure, request and timer routes.

...
# Example of querying a REST service to get the credit of an account
$var(rc) = rest_get("http://getcredit.org/?account=$fU", "$var(credit)", "$var(ct)", "$var(rcode)");

if ($var(rc) < 0) {
	xlog("rest_get() failed with $var(rc), acc=$fU\n");
	send_reply("500", "Server Internal Error");
	exit;
}
if ($var(rcode) >= 300) {
	xlog("L_INFO", "rest_get() rcode=$var(rcode), acc=$fU\n");
	send_reply("403", "Forbidden");
	exit;
}
...

Issues an HTTP POST request to the specified url. The request body will be copied from the send_body_pv pseudo-variable. The MIME Content-Type header for the request will be taken from send_ctype_pv (default is "application/x-www-form-urlencoded")

The mandatory recv_body_pv pseudo-var will hold the body of the HTTP response.

The optional recv_ctype_pv parameter will contain the value of the "Content-Type" header of the response message.

The optional retcode_pv pseudo-var parameter can be given in order to retrieve the HTTP status code of the response message. Since the module is based on libcurl, a 0 value means no HTTP reply arrived at all.

Possible parameter types

This function can be used from the startup, branch, failure, request and timer routes.

...
# Creating a resource using a RESTful service with an HTTP POST request
$var(rc) = rest_post("http://myserver.org/register_user", "$fU", , "$var(body)", "$var(ct)", "$var(rcode)");

if ($var(rc) < 0) {
	xlog("rest_post() failed with $var(rc), user=$fU\n");
	send_reply("500", "Server Internal Error 1");
	exit;
}
if ($var(rcode) >= 300) {
	xlog("rest_post() rcode=$var(rcode), user=$fU\n");
	send_reply("500", "Server Internal Error 2");
	exit;
}
...

Appends 'txt' to the HTTP headers of the subsequent request. Multiple headers can be appended by making multiple calls before executing a request.

The contents of txt should adhere to the specification for HTTP headers (ex. Field: Value)

Parameter types

This function can be used from the startup, branch, failure, request and timer routes.

...
# Example of querying a REST service requiring additional headers

rest_append_hf("Authorization: Bearer mF_9.B5f-4.1JqM");
$var(rc) = rest_get("http://getcredit.org/?account=$fU", "$var(credit)");
...
		

Sends a GET HTTP request. This function behaves exactly the same as rest_get (in terms of input, output and processing), but in an asynchronous way. Script execution is suspended until the entire content of the HTTP response is available.

route {
	...
	async(rest_get("http://getcredit.org/?account=$fU", "$var(credit)", , "$var(rcode)"), resume);
}

route [resume] {
	$var(rc) = $rc;
	if ($var(rc) < 0) {
		xlog("async rest_get() failed with $var(rc), acc=$fU\n");
		send_reply("500", "Server Internal Error");
		exit;
	}

	if ($var(rcode) >= 300) {
		xlog("L_INFO", "async rest_get() rcode=$var(rcode), acc=$fU\n");
		send_reply("403", "Forbidden");
		exit;
	}

	...
}

Sends a POST HTTP request. This function behaves exactly the same as rest_post (in terms of input, output and processing), but in an asynchronous way. Script execution is suspended until the entire content of the HTTP response is available.

route {
	...
	async(rest_post("http://myserver.org/register_user", "$fU", , "$var(body)", "$var(ct)", "$var(rcode)"), resume);
}

route [resume] {
	$var(rc) = $rc;
	if ($var(rc) < 0) {
		xlog("async rest_post() failed with $var(rc), user=$fU\n");
		send_reply("500", "Server Internal Error 1");
		exit;
	}
	if ($var(rcode) >= 300) {
		xlog("async rest_post() rcode=$var(rcode), user=$fU\n");
		send_reply("500", "Server Internal Error 2");
		exit;
	}

	...
}