\documentclass[10pt]{article} \usepackage{graphics} \usepackage{hevea} \usepackage{verbatim} \newcommand{\logoscale}{0.7} \newcommand{\imgscale}{0.58} \newcommand{\insimg}[1]{\insscaleimg{\imgscale}{#1}} \newcommand{\insscaleimg}[2]{ \imgsrc{#2}{} \begin{latexonly} \scalebox{#1}{\includegraphics{#2}} \end{latexonly} } \newcommand{\ns}[1]{\texttt{#1}} \newcommand{\ejabberd}{\texttt{ejabberd}} \newcommand{\Jabber}{Jabber} \newcommand{\modregister}{\texttt{mod\_register}} \newcommand{\modroster}{\texttt{mod\_roster}} \newcommand{\modconfigure}{\texttt{mod\_configure}} \newcommand{\moddisco}{\texttt{mod\_disco}} \newcommand{\modstats}{\texttt{mod\_stats}} \newcommand{\modvcard}{\texttt{mod\_vcard}} \newcommand{\modoffline}{\texttt{mod\_offline}} \newcommand{\modecho}{\texttt{mod\_echo}} \newcommand{\modprivate}{\texttt{mod\_private}} \newcommand{\modtime}{\texttt{mod\_time}} \newcommand{\modversion}{\texttt{mod\_version}} %\setcounter{tocdepth}{3} \title{Ejabberd Installation and Operation Guide} \author{Alexey Shchepin \\ \ahrefurl{mailto:alexey@sevcom.net} \\ \ahrefurl{xmpp:aleksey@jabber.ru}} \date{February 11, 2003} \begin{document} \begin{titlepage} \maketitle{} {\centering \insscaleimg{\logoscale}{logo.png} \par } \end{titlepage} %\newpage \tableofcontents{} \newpage \section{Introduction} \label{sec:intro} \ejabberd{} is a Free and Open Source fault-tolerant distributed \Jabber{} server. It is writen mostly in Erlang. The main features of \ejabberd{} is: \begin{itemize} \item Distributed: You may run \ejabberd{} on a cluster of machines and all of them will serve one Jabber domain. \item Fault-tolerance: You may setup an \ejabberd{} cluster so that all the information required for a properly working service will be stored permanently on more then one node. This means that if one of the nodes crashes, then the others will continue working without disruption. You can also add or replace more nodes ``on the fly''. \item Support for \footahref{http://www.jabber.org/jeps/jep-0030.html}{JEP-0030} (Service Discovery). \item Support for \footahref{http://www.jabber.org/jeps/jep-0039.html}{JEP-0039} (Statistics Gathering). \item Support for \ns{xml:lang} attribute in many XML elements. \item JUD based on users vCards. \end{itemize} \section{Installation} \label{sec:installation} \subsection{Installation Requirements} \label{sec:installreq} To compile \ejabberd{}, you will need the following packages: \begin{itemize} \item GNU Make; \item GCC; \item libexpat 1.95 or later; \item Erlang/OTP R8B or later. \end{itemize} \subsection{Obtaining} \label{sec:obtaining} Currently no stable version has been released. The latest alpha version can be retrieved from CVS\@. \begin{itemize} \item \texttt{export CVSROOT=:pserver:anonymous@jabberstudio.org:/home/cvs} \item \texttt{cvs login} \item Press Enter when asked for a password \item \texttt{cvs -z3 co ejabberd} \end{itemize} \subsection{Compilation} \label{sec:compilation} \begin{verbatim} ./configure make \end{verbatim} TBD %\subsection{Initial Configuration} %\label{sec:initconfig} \subsection{Starting} \label{sec:starting} \ldots{} To use more then 1024 connections, you will need to set environment variable \texttt{ERL\_MAX\_PORTS}: \begin{verbatim} export ERL_MAX_PORTS=32000 \end{verbatim} Note that with this value \ejabberd{} will use more memory (approximately 6MB more)\ldots{} \begin{verbatim} erl -name ejabberd -s ejabberd \end{verbatim} TBD \section{Configuration} \label{sec:configuration} \subsection{Initial Configuration} \label{sec:initconfig} %\verbatiminput{../src/ejabberd.cfg} The configuration file is initially loaded the first time \ejabberd{} is executed, when it is parsed and stored in a database. Subsiquently the configuration is loaded from the database and any commands in the configuration file are appended to the entries in the database. The configuration file consists of a sequence of Erlang terms. Parts of lines after \texttt{`\%'} sign are ignored. Each term is tuple, where first element is name of option, and other are option values. E.\,g.\ if this file does not contain a ``host'' definition, then old value stored in the database will be used. To override old values stored in the database the following lines can be added in config: \begin{verbatim} override_global. override_local. override_acls. \end{verbatim} With this lines old global or local options or ACLs will be removed before adding new ones. \subsubsection{Host Name} \label{sec:confighostname} Option \texttt{hostname} defines name of \Jabber{} domain that \ejabberd{} serves. E.\,g.\ to use \texttt{jabber.org} domain add following line in config: \begin{verbatim} {host, "jabber.org"}. \end{verbatim} %This option is mandatory. \subsubsection{Access Rules} \label{sec:configaccess} Access control in \ejabberd{} is performed via Access Control Lists (ACL). The declarations of ACL in config file have following syntax: \begin{verbatim} {acl, , {, ...}}. \end{verbatim} \texttt{} can be one of following: \begin{description} \item[\texttt{all}] Matches all JIDs. Example: \begin{verbatim} {acl, all, all}. \end{verbatim} \item[\texttt{\{user, \}}] Matches local user with name \texttt{}. Example: \begin{verbatim} {acl, admin, {user, "aleksey"}}. \end{verbatim} \item[\texttt{\{user, , \}}] Matches user with JID \texttt{@} and any resource. Example: \begin{verbatim} {acl, admin, {user, "aleksey", "jabber.ru"}}. \end{verbatim} \item[\texttt{\{server, \}}] Matches any JID from server \texttt{}. Example: \begin{verbatim} {acl, jabberorg, {server, "jabber.org"}}. \end{verbatim} \item[\texttt{\{user\_regexp, \}}] Matches local user with name that matches \texttt{}. Example: \begin{verbatim} {acl, tests, {user, "^test[0-9]*$"}}. \end{verbatim} %$ \item[\texttt{\{user\_regexp, , \}}] Matches user with name that matches \texttt{} and from server \texttt{}. Example: \begin{verbatim} {acl, tests, {user, "^test", "localhost"}}. \end{verbatim} \item[\texttt{\{server\_regexp, \}}] Matches any JID from server that matches \texttt{}. Example: \begin{verbatim} {acl, icq, {server, "^icq\\."}}. \end{verbatim} \item[\texttt{\{node\_regexp, , \}}] Matches user with name that matches \texttt{} and from server that matches \texttt{}. Example: \begin{verbatim} {acl, aleksey, {node_regexp, "^aleksey", "^jabber.(ru|org)$"}}. \end{verbatim} %$ \item[\texttt{\{user\_glob, \}}] \item[\texttt{\{user\_glob, , \}}] \item[\texttt{\{server\_glob, \}}] \item[\texttt{\{node\_glob, , \}}] This is same as above, but uses shell glob patterns instead of regexp. These patterns can have following special characters: \begin{description} \item[\texttt{*}] matches any string including the null string. \item[\texttt{?}] matches any single character. \item[\texttt{[\ldots{}]}] matches any of the enclosed characters. Character ranges are specified by a pair of characters separated by a \texttt{`-'}. If the first character after \texttt{`['} is a \texttt{`!'}, then any character not enclosed is matched. \end{description} \end{description} The following ACLs pre-defined: \begin{description} \item[\texttt{all}] Matches all JIDs. \item[\texttt{none}] Matches none JIDs. \end{description} An entry allowing or denying different services would look similar to this: \begin{verbatim} {access, , [{allow, }, {deny, }, ... ]}. \end{verbatim} When a JID is checked to have access to \texttt{}, the server sequentially checks if this JID mathes one of the ACLs that are second elements in each tuple in list. If it is matched, then the first element of matched tuple is returned else ``\texttt{deny}'' is returned. Example: \begin{verbatim} {access, configure, [{allow, admin}]}. {access, something, [{deny, badmans}, {allow, all}]}. \end{verbatim} Following access rules pre-defined: \begin{description} \item[\texttt{all}] Always return ``\texttt{allow}'' \item[\texttt{none}] Always return ``\texttt{deny}'' \end{description} \subsubsection{Shapers Configuration} \label{sec:configshaper} With shapers is possible to bound connection traffic. The declarations of shapers in config file have following syntax: \begin{verbatim} {shaper, , }. \end{verbatim} Currently implemented only one kind of shaper: \texttt{maxrate}. It have following syntax: \begin{verbatim} {maxrate, } \end{verbatim} where \texttt{} means maximum allowed incomig rate in bytes/second. E.\,g.\ to define shaper with name ``\texttt{normal}'' and maximum allowed rate 1000\,bytes/s, add following line in config: \begin{verbatim} {shaper, normal, {maxrate, 1000}}. \end{verbatim} \subsubsection{Listened Sockets} \label{sec:configlistened} Option \texttt{listen} defines list of listened sockets and what services runned on them. Each element of list is a tuple with following elements: \begin{itemize} \item Port number; \item Module that serves this port; \item Function in this module that starts connection (likely will be removed); \item Options to this module. \end{itemize} Currently three modules are implemented: \begin{description} \item[\texttt{ejabberd\_c2s}] This module serves C2S connections. Following options defined: \begin{description} \item[\texttt{\{access, \}}] This option defines access of users to this C2S port. Default value is ``\texttt{all}''. \item[\texttt{\{shaper, \}}] This option is like previous, but use shapers instead of ``\texttt{allow}'' and ``\texttt{deny}''. Default value is ``\texttt{none}''. \end{description} \item[\texttt{ejabberd\_s2s\_in}] This module serves incoming S2S connections. \item[\texttt{ejabberd\_service}] This module serves connections to \Jabber{} services (i.\,e.\ that use the \texttt{jabber:component:accept} namespace). \end{description} For example, the following configuration defines that C2S connections are listened on port 5222 and denied for user ``\texttt{bad}'', S2S on port 5269 and that service \texttt{conference.jabber.org} must be connected to port 8888 with a password ``\texttt{secret}''. Also all users except admins have traffic limit 1000\,b/s. \begin{verbatim} {acl, blocked, {user, "bad"}}. {access, c2s, [{deny, blocked}, {allow, all}]}. {shaper, normal, {maxrate, 1000}}. {access, c2s_shaper, [{none, admin}, {normal, all}]}. {listen, [{5222, ejabberd_c2s, start, [{access, c2s}, {shaper, c2s_shaper}]}, {5269, ejabberd_s2s_in, start, []}, {8888, ejabberd_service, start, [{host, "conference.jabber.org", [{password, "secret"}]}]} ]}. \end{verbatim} \subsubsection{Modules} \label{sec:configmodules} Option \texttt{modules} defines the list of modules that will be loaded after \ejabberd{} startup. Each list element is a tuple where first element is a name of a module and second is list of options to this module. See section~\ref{sec:modules} for detailed information on each module. Example: \begin{verbatim} {modules, [ {mod_register, []}, {mod_roster, []}, {mod_configure, []}, {mod_disco, []}, {mod_stats, []}, {mod_vcard, []}, {mod_offline, []}, {mod_echo, [{host, "echo.localhost"}]}, {mod_private, []}, {mod_time, [{iqdisc, no_queue}]}, {mod_version, []} ]}. \end{verbatim} \subsection{Online Configuration and Monitoring} \label{sec:onlineconfig} To perform online reconfiguration of \ejabberd{} you will need to have \modconfigure{} loaded (see section~\ref{sec:modconfigure}). It is also highly recommended to load \moddisco{} as well (see section~\ref{sec:moddisco}), because \modconfigure{} is highly integrated with it. Additionally it is recommended to use a disco- and xdata-capable client such as \footahref{http://www.jabber.ru/projects/tkabber/index\_en.html}{Tkabber} (which was developed synchronously with \ejabberd{}, its CVS version supports most of \ejabberd{} features). On disco query \ejabberd{} returns following items: \begin{itemize} \item Identity of server. \item List of features, including defined namespaces. \item List of JIDs from route table. \item List of disco-nodes described in following subsections. \end{itemize} \begin{figure}[htbp] \centering \insimg{disco.png} \caption{Tkabber Discovery window} \label{fig:disco} \end{figure} \subsubsection{Node \texttt{config}: Global Configuration} Under this node the following nodes exists: \paragraph{Node \texttt{config/hostname}} Via \ns{jabber:x:data} queries to this node possible to change host name of this \ejabberd{} server. (See figure~\ref{fig:hostname}) (Currently this works correctly only after a restart) \begin{figure}[htbp] \centering \insimg{confhostname.png} \caption{Editing of hostname} \label{fig:hostname} \end{figure} \paragraph{Node \texttt{config/acls}} Via \ns{jabber:x:data} queries to this node it is possible to edit ACLs list. (See figure~\ref{fig:acls}) \begin{figure}[htbp] \centering \insimg{confacls.png} \caption{Editing of ACLs} \label{fig:acls} \end{figure} \paragraph{Node \texttt{config/access}} Via \ns{jabber:x:data} queries to this node it is possible to edit access rules. \paragraph{Node \texttt{config/remusers}} Via \ns{jabber:x:data} queries to this node it is possible to remove users. If removed user is online, then he will be disconnected. Also user-related data (e.g. his roster) is removed (but appropriate module must be loaded). \subsubsection{Node \texttt{online users}: List of Online Users} \subsubsection{Node \texttt{all users}: List of Registered User} \begin{figure}[htbp] \centering \insimg{discoallusers.png} \caption{Discovery all users} \label{fig:discoallusers} \end{figure} \subsubsection{Node \texttt{outgoing s2s}: List of Outgoing S2S connections} \subsubsection{Node \texttt{running nodes}: List of Running \ejabberd{} Nodes} \begin{figure}[htbp] \centering \insimg{discorunnodes.png} \caption{Discovery running nodes} \label{fig:discorunnodes} \end{figure} \subsubsection{Node \texttt{stopped nodes}: List of Stopped Nodes} TBD \section{Distribution} \label{sec:distribution} \subsection{How it works} \label{sec:howitworks} A \Jabber{} domain is served by one or more \ejabberd{} nodes. These nodes can be run on different machines that are connected via a network. They all must have the ability to connect to port 4369 of all another nodes, and must have the same magic cookie (see Erlang/OTP documentation, in other words the file \texttt{\~{}ejabberd/.erlang.cookie} must be the same on all nodes). This is needed because all nodes exchange information about connected users, S2S connections, registered services, etc\ldots Each \ejabberd{} node must run following modules: \begin{itemize} \item router; \item local router. \item session manager; \item S2S manager; \end{itemize} \subsubsection{Router} This module is the main router of \Jabber{} packets on each node. It routes them based on their destinations domains. It has two tables: local and global routes. First, domain of packet destination searched in local table, and if it found, then the packet is routed to appropriate process. If no, then it searches in global table, and is routed to the appropriate \ejabberd{} node or process. If itdoes not exists in either table, then it sent to the S2S manager. \subsubsection{Local Router} This module routes packets which have a destination domain equal to this server name. If destination JID has a node, then it routed to the session manager, else it is processed depending on it's content. \subsubsection{Session Manager} This module routes packets to local users. It searches for what user resource packet must be sended via presence table. If this resource is connected to this node, it is routed to C2S process, if it connected via another node, then the packet is sent to session manager on that node. \subsubsection{S2S Manager} This module routes packets to other \Jabber{} servers. First, it checks if an open S2S connection from the domain of the packet source to the domain of packet destination already exists. If it is open on another node, then it routes the packet to S2S manager on that node, if it is open on this node, then it is routed to the process that serves this connection, and if a connection does not exist, then it is opened and registered. \appendix{} \section{Built-in Modules} \label{sec:modules} \subsection{Common Options} \label{sec:modcommonopts} Following options used by many modules, so they described in separate section. \subsubsection{Option \texttt{iqdisc}} Many modules define handlers for processing IQ queries of different namespaces to this server or to user (e.\,g.\ to \texttt{myjabber.org} or to \texttt{user@myjabber.org}). This option defines processing discipline of these queries. Possible values are: \begin{description} \item[\texttt{no\_queue}] All queries of namespace with this processing discipline processed immediately. This also means that no other packets can be processed until finished this. Hence this discipline is not recommended if processing of query can take relative many time. \item[\texttt{one\_queue}] In this case created separate queue for processing IQ queries of namespace with this discipline, and processing of this queue done in parallel with processing of other packets. This discipline is most recommended. \item[\texttt{parallel}] In this case for all packets of namespace with this discipline spawned separate Erlang process, so all this packets processed in parallel. Although spawning of Erlang process have relative low cost, this can broke server normal work, because Erlang have limit of 32000 processes. \end{description} Example: \begin{verbatim} {modules, [ ... {mod_time, [{iqdisc, no_queue}]}, ... ]}. \end{verbatim} \subsubsection{Option \texttt{host}} Some modules may act as services, and wants to have different domain name. This option explicitly defines this name. Example: \begin{verbatim} {modules, [ ... {mod_echo, [{host, "echo.myjabber.org"}]}, ... ]}. \end{verbatim} \subsection{\modregister{}} \label{sec:modregister} \subsection{\modroster{}} \label{sec:modroster} \subsection{\modconfigure{}} \label{sec:modconfigure} \subsection{\moddisco{}} \label{sec:moddisco} \subsection{\modstats{}} \label{sec:modstats} This module adds support of \footahref{http://www.jabber.org/jeps/jep-0039.html}{JEP-0039} (Statistics Gathering). Options: \begin{description} \item[\texttt{iqdisc}] \ns{http://jabber.org/protocol/stats} IQ queries processing discipline. \end{description} TBD about access. \subsection{\modvcard{}} \label{sec:modvcard} \subsection{\modoffline{}} \label{sec:modoffline} \subsection{\modecho{}} \label{sec:modecho} \subsection{\modprivate{}} \label{sec:modprivate} This module adds support of \footahref{http://www.jabber.org/jeps/jep-0049.html}{JEP-0049} (Private XML Storage). Options: \begin{description} \item[\texttt{iqdisc}] \ns{jabber:iq:private} IQ queries processing discipline. \end{description} \subsection{\modtime{}} \label{sec:modtime} This module answers UTC time on \ns{jabber:iq:time} queries. Options: \begin{description} \item[\texttt{iqdisc}] \ns{jabber:iq:time} IQ queries processing discipline. \end{description} \subsection{\modversion{}} \label{sec:modversion} This module answers \ejabberd{} version on \ns{jabber:iq:version} queries. Options: \begin{description} \item[\texttt{iqdisc}] \ns{jabber:iq:version} IQ queries processing discipline. \end{description} \section{I18n/L10n} \label{sec:i18nl10n} Many modules supports \texttt{xml:lang} attribute inside IQ queries. E.\,g.\ on figure~\ref{fig:discorus} (compare with figure~\ref{fig:disco}) showed reply on following query: \begin{verbatim} \end{verbatim} \begin{figure}[htbp] \centering \insimg{discorus.png} \caption{Discovery result when \texttt{xml:lang='ru'}} \label{fig:discorus} \end{figure} \end{document}