ari-proxy

Ari-proxy connects Asterisk, an open source communication server, to the Apache Kafka distributed streaming platform.

Table of contents

1. Abstract
2. Getting started
3. Metrics
4. Compatibility
5. Contributing & feedback
6. Credit & License
7. Acknowledgements

Abstract

The motivation to create ari-proxy arose from the need to build distributed and resilient telephony services scaling up to millions of active users. Ari-proxy makes use of Kafka’s built-in routing concepts to ensure consistency of message streams and proper dispatching to the call-controller, the application implementing the service logic.

Please see docs/concepts.md for details on the concepts of message routing and session mapping.

Getting started

In order to operate ari-proxy, make sure you have a running instance of both Asterisk and Kafka server.

Prerequisites

ari-proxy is written in Java, so you should install and setup Java before continuing. The project is managed by maven, which requires you to install maven as well.

Building

Build the fat jar in target/:

mvn package

Configuration

ari-proxy expects the following configuration files, which should be passed to the jvm when running the fat-jar:

config	optional	purpose
service.conf	no	configure the service, see our template: service.conf.sample
log4j2.xml	yes	configure logging (if not specified, a bundled config will be used logging to STDOUT only)
jolokia.properties	no	configure jolokia agent properties, see our template: jolokia.properties.sample

Running

Run the fat jar:

java -Dconfig.file=/path/to/service.conf [-Dlog4j.configurationFile=/path/to/log4j2.xml] -jar target/ari-proxy-1.3.0-fat.jar

Persistence-store

There are two ways to persist the in-memory data storage (Asterisk Object ID -> Kafka Routing Key).

First there is Redis (default). The redis needs to be configured in service.conf file in order to be able to connect. Also a keyspace needs to be configured. Second possibility to store the data is Cassandra. This is a more robust but more complex configuration as it provides HA and better scalability. You need to configure the Cassandra nodes in the "datastax" section of "service.conf"

In order to choose one option you need to enable the one or the other backend by set the parameter persistence-store to one of these values:

• "io.retel.ariproxy.persistence.plugin.CassandraPersistenceStore"

• "io.retel.ariproxy.persistence.plugin.RedisPersistenceStore"

In case you want to use Cassandra you need to create a keyspace and table in Cassandra. This snippet might help to create one. (please adapt replication factor and names according your setup)

CREATE KEYSPACE retel with replication = {'class':'SimpleStrategy','replication_factor':1};

USE retel;

CREATE TABLE retel (
"key" text primary key,
"value" text
);

Hint: do not forget some kind of housekeeping by adding TTL or a cleanup job.

Monitoring

Health-Check

There are three routes to check for service health:

• /health
• /health/smoke
• /health/backing-services

/health is meant to check if the service itself is healthy in terms of JVM,Akka etc. settings. Yet to be implemented correctly.

/health/smoke is used for deployment to check if the service is started. Only checks for open port.

/health/backing-services checks all services that are necessary for running the application e.g. Kafka, Asterisk, Redis/Cassandra.

Metrics

Ari-proxy provides service specific metrics using the micrometer framework which are available via JMX or HTTP.

For further details see: Metrics

Compatibility

We aim for compatibility with the latest stable release of

• Java OpenJDK 17
• Asterisk
• the utilized Akka Modules

Contributing & feedback

To report a bug or make a request for new features, use the Issues Page in the ari-proxy Github project. We welcome any contributions. Please see the Developer Guidelines for instructions on how to submit changes.

Credit & License

ari-proxy is maintained by the folks at sipgate and licensed under the terms of the AGPL license.

Maintainers of this repository:

• Jöran @vinzens
• Maya @ironmaya
• Mia @mia-krause
• Sven @SvenKube
• Max @IllTemperedMax

Please refer to the Git commit log for a complete list of contributors.

Acknowledgements

ari-proxy is not the first of its kind. This project was inspired by the concepts underlying both go-ari-proxy by N-Visible as well as ari-proxy by CyCore Systems.