rest_client Module


Table of Contents

1. Admin Guide
1.1. Overview
1.2. Dependencies
1.2.1. OpenSIPS Modules
1.2.2. External Libraries or Applications
1.3. Exported Parameters
1.3.1. curl_timeout (integer)
1.3.2. connection_timeout (integer)
1.3.3. connect_poll_interval (integer)
1.3.4. max_async_transfers (integer)
1.3.5. ssl_verifypeer (integer)
1.3.6. ssl_verifyhost (integer)
1.3.7. ssl_capath (integer)
1.4. Exported Functions
1.4.1. rest_get(url, body_pv[, [ctype_pv][, [retcode_pv]]])
1.4.2. rest_post(url, send_body_pv, [send_ctype_pv], recv_body_pv[, [recv_ctype_pv][, [retcode_pv]]])
1.4.3. rest_append_hf(txt)
1.5. Exported Asynchronous Functions
1.5.1. rest_get(url, body_pv[, [ctype_pv][, [retcode_pv]]])
1.5.2. rest_post(url, send_body_pv, [send_ctype_pv], recv_body_pv[, [recv_ctype_pv][, [retcode_pv]]])
2. Contributors
2.1. By Commit Statistics
2.2. By Commit Activity
3. Documentation
3.1. Contributors

List of Tables

2.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
2.2. Most recently active contributors(1) to this module

List of Examples

1.1. Setting the curl_timeout parameter
1.2. Setting the connection_timeout parameter
1.3. Setting the connect_poll_interval parameter
1.4. Setting the max_async_transfers parameter
1.5. Setting the ssl_verifypeer parameter
1.6. Setting the ssl_verifyhost parameter
1.7. Setting the ssl_capath parameter
1.8. rest_get usage
1.9. rest_post usage
1.10. rest_append_hf usage
1.11. async rest_get usage
1.12. async rest_post usage

Chapter 1. Admin Guide

1.1. Overview

The rest_client module provides a means of interacting with an HTTP server by doing RESTful queries, such as GET and POST.

1.2. Dependencies

1.2.1. OpenSIPS Modules

The following modules must be loaded before this module:

  • No dependencies on other OpenSIPS modules..

1.2.2. External Libraries or Applications

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

  • libcurl.

1.3. Exported Parameters

1.3.1. curl_timeout (integer)

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.

Example 1.1. Setting the curl_timeout parameter

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

1.3.2. connection_timeout (integer)

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

Default value is 20 seconds.

Example 1.2. Setting the connection_timeout parameter

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

1.3.3. connect_poll_interval (integer)

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.

Example 1.3. Setting the connect_poll_interval parameter

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

1.3.4. max_async_transfers (integer)

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.

Example 1.4. Setting the max_async_transfers parameter

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

1.3.5. ssl_verifypeer (integer)

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).

Example 1.5. Setting the ssl_verifypeer parameter

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

1.3.6. ssl_verifyhost (integer)

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).

Example 1.6. Setting the ssl_verifyhost parameter

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

1.3.7. ssl_capath (integer)

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

Example 1.7. Setting the ssl_capath parameter

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

1.4. Exported Functions

1.4.1.  rest_get(url, body_pv[, [ctype_pv][, [retcode_pv]]])

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

  • url - String, pseudo-variable, or a String which includes pseudo-variables. (useful for specifying additional attribute-value fields in the URL)

  • body_pv, ctype_pv, retcode_pv - pseudo-variables

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

Example 1.8. rest_get usage

...
# 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;
}
...

1.4.2.  rest_post(url, send_body_pv, [send_ctype_pv], recv_body_pv[, [recv_ctype_pv][, [retcode_pv]]])

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

  • url, send_body_pv, send_type_pv - String, pseudo-variable, or a String which includes pseudo-variables.

  • recv_body_pv, recv_ctype_pv, retcode_pv - pseudo-variables

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

Example 1.9. rest_post usage

...
# 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;
}
...

1.4.3.  rest_append_hf(txt)

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

  • txt - String, pseudo-variable, or a String which includes pseudo-variables. (useful for specifying additional attribute-value fields in the URL)

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

Example 1.10. rest_append_hf usage

...
# 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)");
...
		

1.5. Exported Asynchronous Functions

1.5.1.  rest_get(url, body_pv[, [ctype_pv][, [retcode_pv]]])

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.

Example 1.11. async rest_get usage

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;
	}

	...
}

1.5.2.  rest_post(url, send_body_pv, [send_ctype_pv], recv_body_pv[, [recv_ctype_pv][, [retcode_pv]]])

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.

Example 1.12. async rest_post usage

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;
	}

	...
}

Chapter 2. Contributors

2.1. By Commit Statistics

Table 2.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)

 NameDevScoreCommitsLines ++Lines --
1. Liviu Chircu (@liviuchircu)65392250413
2. Jarrod Baumann (@jarrodb)6313132
3. Bogdan-Andrei Iancu (@bogdan-iancu)536718
4. Razvan Crainea (@razvancrainea)5388
5. Andrey Vorobiev (@andrey-vorobiev)2130

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits. Regarding imported patches/code, we do our best to count the work on behalf of the proper owner, as per the "fix_authors" and "mod_renames" arrays in opensips/doc/build-contrib.sh. If you identify any patches/commits which do not get properly attributed to you, please submit a pull request which extends "fix_authors" and/or "mod_renames".

(3) ignoring whitespace edits, renamed files and auto-generated files

2.2. By Commit Activity

Table 2.2. Most recently active contributors(1) to this module

 NameCommit Activity
1. Liviu Chircu (@liviuchircu)Mar 2013 - May 2019
2. Razvan Crainea (@razvancrainea)Aug 2015 - Sep 2018
3. Bogdan-Andrei Iancu (@bogdan-iancu)Oct 2014 - Jun 2018
4. Andrey Vorobiev (@andrey-vorobiev)Feb 2017 - Feb 2017
5. Jarrod Baumann (@jarrodb)Apr 2015 - May 2015

(1) including any documentation-related commits, excluding merge commits

Chapter 3. Documentation

3.1. Contributors

Last edited by: Liviu Chircu (@liviuchircu), Bogdan-Andrei Iancu (@bogdan-iancu), Jarrod Baumann (@jarrodb).

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