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Understanding ejabberd and its dependencies

We wanted to make sure that ejabberd is modular and that parts that can be of interest for other Erlang projects can be reused.

Not only we are massive open source contributors to Erlang community and ecosystem, but we are also trying to help even more by reviewing your pull requests. Do not hesitate to submit some on any of the many repositories mentioned here.

ejabberd dependencies

ejabberd code based is split among several repositories so effectively ejabberd code is much more than what is in its primary repository.

Required dependencies

The main ejabberd repository is processone/ejabberd

There is hundreds of forks, but we actively maintain ejabberd to make it the most reliable and up to date version. This is thus your best starting point.

When you build ejabberd yourself, the build chain will download a few Erlang dependencies:

  • processone/cache_tab: Flexible in-memory Erlang caching module.
  • processone/iconv: Native iconv driver for Erlang. This is use for fast character encoding conversion.
  • processone/fast_xml: Fast native Expat based Erlang XML parsing library. XML is the core of XMPP so we needed to provide the fast and more robust XML parsing stack as possible. It means that if you are looking for a great XML parser, reusing p1_xml is probably a great idea.
  • processone/stringprep: Fast and efficient Erlang Stringprep native driver. Stringprep is heavily used in XMPP to define encoding rules of various XMPP objects.
  • processone/fast_yaml: Native Erlang interface to libyaml, for fast robust YAML parsing. This is needed by our new config file format.
  • processone/ezlib: Native zlib driver for Erlang. Used for fast / efficient stream compression.
  • processone/fast_tls: Erlang native driver for TLS / SSL. It is build for performance and is more scalable that Erlang SSL driver. If your Erlang server is handling heavy load and is using TLS, we strongly recommend you check / compare with this driver.
  • processone/esip: ProcessOne SIP protocol support to add SIP-based voice capabilities to ejabberd.
  • processone/stun: Implementation of Session Traversal Utilities for NAT. It is used for XMPP and SIP media capabilities, to help client discover their visible IP address and allow them to get in touch through NAT. This is basically useful for voice and file transfers.
  • processone/p1_utils: This is extra Erlang modules developed for ejabberd but that can be useful in other Erlang applications.
  • processone/p1_logger: Logger wrapper to allow selecting your preferred logger at build time.
  • basho/lager: Erlang logger module.
  • DeadZen/goldrush: Small Erlang app that provides fast event stream processing. It is used by lager.
  • vaxelfel/eHyperLogLog: HyperLogLog, a distinct values estimator, in Erlang. Used for analytics.

Optional dependencies

Then, we use a few other dependent repositories that may be used if you have enabled support in the configure script.

Here are the dependencies for relational database support:

Here are the dependencies for Elixir support:

After you have build ejabberd from source, you will find all the dependencies downloaded and build in the deps directory.

As you see, there is much more Erlang code produce at ProcessOne and contributed to the Erlang community than just ejabberd repository.

ejabberd contributions

This is not dependencies, but simply modules that you may find nice to add to your ejabberd deployment.

We attempted to gather some of the more useful ejabberd modules in a contribution repository to ease discovery.

This repository is available on Github: ejabberd-contribs

We are thinking about a better approach for ejabberd contributions discovery. More on that soon.