Prosody
Prosody (pronunciation: 1, 2) is an XMPP server written in the Lua programming language. Prosody is designed to be lightweight and highly extensible. It is licensed under a permissive MIT license. Prosody is available for Arch Linux in the Community repository with some optional dependencies available from the AUR.
Previous experience with building and installing packages from the AUR and basic knowledge of XMPP will be very helpful when following the guide. As per usual, when command line commands are provided, lines preceded by $
indicate that the command may be run as a regular user, while lines preceded by #
indicate that the command must be run as root
.
Contents
Installation
Prosody is available in the Community repository, and is straightforward to install via pacman:
# pacman -S prosody
Optional Dependencies
Prosody has optional depedencies that although not strictly required for its operation, provide useful features. These dependencies may also have to be built and installed from the AUR. If you are unfamiliar with how to build and install packages from the AUR please see this tutorial.
- TLS/SSL Support (Recommended)
- Allow Prosody to encrypt streams to prevent eavesdropping.
Requires: lua51-sec (Community)
- Better Connection Scaling (Recommended)
- Allow Prosody to use libevent to handle a greater number of simultaneous connections.
Requires: lua51-eventAUR (AUR)
- Stream Compression
- Allow Prosody to compress client-to-server streams for compatible clients to save bandwidth.
Requires: lua51-zlib (Community)
- Cyrus SASL Support
- Allow Prosody to use the Cyrus SASL library to provide authentication.
Requires: lua-cyrussaslAUR (AUR)
Configuration
posix
module and pidfile
setting contained in the default configuration file are required for Prosody's proper operation on Arch Linux. Please do not disable or alter them.The main configuration file is located at /etc/prosody/prosody.cfg.lua
, information on how to configure Prosody can be found in Prosody's documentation. The syntax of the configuration file can be checked after any changes are made by running:
$ luac -p /etc/prosody/prosody.cfg.lua
No output means the syntax is correct.
Logging
The Arch Linux Prosody package is pre-configured to log to /var/log/prosody/prosody.err
and /var/log/prosody/prosody.log
. The Arch Linux package also includes a logrotate script in /etc/logrotate.d/prosody
, configure it to suit your needs. If you enabled the olddir
path for rotated log files in /etc/logrotate.conf
you will likely want to move old prosody log files. First create the directory:
# mkdir /var/log/old/prosody
Then uncomment the olddir
line in /etc/logrotate.d/prosody
.
Operation
You can start Prosody through the included Systemd script:
# systemctl start prosody
To automatically start Prosody at boot execute:
# systemctl enable prosody
Prosody uses the default XMPP ports, 5222 and 5269, for client-to-server and server-to-server communications respectively. Configure your firewall as necessary.
You can manipulate Prosody users by using the prosodyctl
program. To add a user:
# prosodyctl adduser <JID>
admins
list in the configuration file.Issue man prosodyctl
to see the man page for prosodyctl
.
Security
User Registration
Prosody supports XMPP's in-band registration standard, which allows users to register with an XMPP client from within their client and change their passwords. While this is convenient for users it does not allow administrators to moderate the registration of new users. As such, the register
module is enabled in the default configuration but allow_registration
is set to false
. This allows existing users to change their passwords from within their client but does not allow new users to register themselves.
watchregistrations
and welcome
modules useful.Stream Encryption
Prosody can utilize TLS certificates to encrypt client-to-server communications (if the proper dependencies are installed). See the relevant sections of prosody.cfg.lua
to configure Prosody to utilize these certificates.
To require encryption for client-to-server communications add the following to your configuration file:
/etc/prosody/prosody.cfg.lua
Host "*" c2s_require_encryption = true
Similarly, for server-to-server communications you may do:
/etc/prosody/prosody.cfg.lua
Host "*" s2s_require_encryption = true
While requiring client-to-server encryption is generally a good idea, please keep in mind that some popular XMPP services such as Google Talk/Gmail do not support server-to-server encryption.
Listing Users
A simple way to see a list of the registered users is
# ls -l /var/lib/prosody/*/accounts/*
alternatively, you can download the module mod_listusers.lua, and use it as
# prosodyctl mod_listusers
Removal
Prosody and all its (required) dependencies can be removed using pacman:
# pacman -Rs prosody
Check above for optional dependencies that may also be removed.
Prosody may leave the following directories on your filesystem that you may want to remove if you do not plan on reinstalling Prosody: /etc/prosody
, /var/lib/prosody
, /var/log/prosody
, and /var/log/old/prosody
.
Tips & Tricks
Components
Prosody supports XMPP components, which provide extra services to clients. Components are either provided internally by special Prosody modules or externally using the protocol specified in XEP-0114.
VirtualHost
s defined in prosody.cfg.lua
. Attempting to host a component on the same hostname as a defined VirtualHost
will result in errors.By default, Prosody will listen for external components. If you do not plan to use any external components with Prosody you can disable this behavior by adding the following your configuration:
/etc/prosody/prosody.cfg.lua
component_ports = {}
Multi-User Chat
A common component used with XMPP servers is Multi-User Chat (MUC), which allows conferences between multiple users. MUC is provided as an internal component with Prosody. To enable MUC add the following to your configuration file:
/etc/prosody/prosody.cfg.lua
Component "conference.example.com" "muc"
This will enable the MUC component on host conference.example.com
.
Prosody Modules
Prosody Modules is a collection of extra modules not distributed with Prosody. These modules are in various states of development from highly experimental to relatively stable. You should consult a given module's wiki page for more information. An example of an extra module is pastebin
, which when loaded will intercept long messages (for example, log file output) and replace them with a link to a pastebin hosted using Prosody's internal HTTP server (provided by the core module, httpserver
).
To use an extra module download its raw file(s) from the source browser (when viewing a file, search for the link "View raw file"). Alternatively and likely easier, use Mercurial to clone the entire repository:
$ hg clone https://prosody-modules.googlecode.com/hg/ prosody-modules
Now you can copy the module (and any additional files it needs) to Prosody's module directory at /usr/lib/prosody/modules
. To enable the module add it to your modules_enabled
list in your prosody.cfg.lua
for the host or component you wish to use it for. For example, to use the pastebin
module on a MUC component:
/etc/prosody/prosody.cfg.lua
Component "conference.example.com" "muc" modules_enabled = { "pastebin" }
mod_foo.lua
but simply enabled by adding foo
to the modules_enabled
list.Console
console
module on a multi-user system.The console
module provides a telnet console from which administrative operations and queries can be performed. You can connect to the console by issuing:
$ telnet localhost 5582
You of course need the telnet
program provided by the inetutils
package. Use the help
command in the console to get usage help.
The console even allows you to execute Lua commands directly on the server by preceding a command with >
. For example to see if a client connection is compressed:
> full_sessions["romeo@montague.lit/Resource"].compressed
Will return true
if the connection is compressed or nil
if it is not.
Troubleshooting
One of Prosody's primary design principles is to be simple to use and configure. However, issues can still arise (and likely will as is the case with any complex software). If you encounter a problem there are a variety of steps you can take to narrow down the cause:
- Check for known issues
Look at the release notes for your Prosody version to see if your issue is listed as a known issue. Also check the issue tracker to see if your issue has already been reported. - Check configuration syntax
Runluac -p /etc/prosody/prosody.cfg.lua
to check for any syntax errors in your configuration file. If there is no output your syntax is fine. - Check the log files
Log files are located in/var/log/prosody
. Errors are only logged if there is a critical problem so always address those issues. If you think you have a very low level issue (like protocol compatibility between clients and servers with Prosody) then you can enable the very verbose debug level logging. The default configuration file has commented out lines to log debug messages toprosody.debug
. - Check permissions
The Prosody package should add a newprosody
user and group to your system and set appropriate permissions, but it is always good to double check. Ensure that/etc/prosody
and/var/lib/prosody
are owned by theprosody
user and that the user has appropriate permissions to read and write to those paths and all contained files. - Check listening ports
When troubleshooting connection issues make sure that Prosody is actually listening for connections. You may do so by runningss -tul
and making sure thatxmpp-client
(port 5222) andxmpp-server
(port 5269) are listed. - Restart
Like most things, it doesn't hurt to restart Prosody (/etc/rc.d/prosody restart
) to see if it resolves an issue.
If you're unable to resolve your issue yourself there are a variety of resources you can use to seek help. In order of immediacy with which you'll likely receive help:
- XMPP Conference:
prosody@conference.prosody.im
- Mailing List: Web Interface, Email
- Arch Forums (for package issues)
Development
Change Log
You may view the change log of the Prosody package by issuing the following command:
$ pacman -Qc prosody
Packages
Two development packages are maintained for Prosody in the AUR, prosody-develAUR and prosody-hg]AUR. prosody-devel
tracks the latest source release of a development version (alpha, beta, release candidate) and will actually be behind the stable version if a final version of the development version is released. prosody-hg
tracks the Mercurial repository tip for Prosody and will always contain the latest code as it is checked in. Both packages are built similarly to the stable package.
More Resources
Development
- Issue Tracker
- Source Repository
- Prosody Modules (Non-Core Modules)
Documentation
Communication
- Mailing Lists: prosody-dev, prosody-users
- Conference:
prosody@conference.prosody.im
- Blog: Prosodical Thoughts
Social
See also
- Official documentation
- Prosodical Thoughts (Blog)
- Issue Tracker
- Prosody Modules (Extra Modules)