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* [PATCH] gnu: Add Prosody service.
@ 2017-01-04 21:55 Clément Lassieur
  2017-01-05 10:34 ` Hartmut Goebel
  2017-01-07 21:29 ` Ludovic Courtès
  0 siblings, 2 replies; 19+ messages in thread
From: Clément Lassieur @ 2017-01-04 21:55 UTC (permalink / raw)
  To: guix-devel

* gnu/services/messaging.scm: New file.
* gnu/services/configuration.scm: New exported procedures.
* gnu/packages/messaging.scm (prosody)[arguments]: Add 'fix-makefile'
  phase.
  In 'wrap-programs' phase, add 'openssl' and 'coreutils' to 'PATH'.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add gnu/services/messaging.scm.
* doc/guix.texi (Messaging Services): New section.
---
 doc/guix.texi                  | 393 +++++++++++++++++++++-
 gnu/local.mk                   |   1 +
 gnu/packages/messaging.scm     |  48 ++-
 gnu/services/configuration.scm |   3 +
 gnu/services/messaging.scm     | 728 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 1157 insertions(+), 16 deletions(-)
 create mode 100644 gnu/services/messaging.scm

diff --git a/doc/guix.texi b/doc/guix.texi
index adc7fefca..1a092d169 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -29,7 +29,8 @@ Copyright @copyright{} 2016 John Darrington@*
 Copyright @copyright{} 2016 ng0@*
 Copyright @copyright{} 2016 Jan Nieuwenhuizen@*
 Copyright @copyright{} 2016 Julien Lepiller@*
-Copyright @copyright{} 2016 Alex ter Weele
+Copyright @copyright{} 2016 Alex ter Weele@*
+Copyright @copyright{} 2017 Clément Lassieur
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -204,6 +205,7 @@ Services
 * Desktop Services::            D-Bus and desktop services.
 * Database Services::           SQL databases.
 * Mail Services::               IMAP, POP3, SMTP, and all that.
+* Messaging Services::          Messaging services.
 * Kerberos Services::           Kerberos services.
 * Web Services::                Web servers.
 * Network File System::         NFS related services.
@@ -8094,6 +8096,7 @@ declaration.
 * Desktop Services::            D-Bus and desktop services.
 * Database Services::           SQL databases.
 * Mail Services::               IMAP, POP3, SMTP, and all that.
+* Messaging Services::          Messaging services.
 * Kerberos Services::           Kerberos services.
 * Web Services::                Web servers.
 * Network File System::         NFS related services.
@@ -11708,6 +11711,394 @@ remote servers.  Run @command{man smtpd.conf} for more information.
 @end table
 @end deftp
 
+@node Messaging Services
+@subsubsection Messaging Services
+
+@cindex messaging
+@cindex jabber
+@cindex XMPP
+The @code{(gnu services messaging)} module provides Guix service
+definitions for messaging services: currently only Prosody is supported.
+
+@subsubheading Prosody Service
+
+@deffn {Scheme Variable} prosody-service-type
+This is the type for the @uref{http://prosody.im, Prosody XMPP
+communication server}.  Its value must be a @code{prosody-configuration}
+record as in this example:
+
+@example
+(service prosody-service-type
+         (prosody-configuration
+          (modules-enabled (cons "groups" %default-modules-enabled))
+          (int-components
+           (list
+            (int-component-configuration
+             (hostname "conference.example.net")
+             (plugin "muc")
+             (mod-muc (mod-muc-configuration)))))
+          (virtualhosts
+           (list
+            (virtualhost-configuration
+             (domain "example.net"))))))
+@end example
+
+See below for details about @code{prosody-configuration}.
+
+@end deffn
+
+By default, Prosody does not need much configuration.  Only one
+@code{virtualhosts} field is needed: it specifies the domain you wish
+Prosody to serve.
+
+Prosodyctl will help you generate X.509 certificates and keys:
+
+@example
+prosodyctl cert request example.net
+@end example
+
+The available configuration parameters follow.  Each parameter
+definition is preceded by its type; for example, @samp{string-list foo}
+indicates that the @code{foo} parameter should be specified as a list of
+strings.  Types starting with @code{maybe-} denote parameters that won't
+show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
+
+There is also a way to specify the configuration as a string, if you
+have an old @code{prosody.cfg.lua} file that you want to port over from
+some other system; see the end for more details.
+
+@c The following documentation was initially generated by
+@c (generate-documentation) in (gnu services messaging).  Manually maintained
+@c documentation is better, so we shouldn't hesitate to edit below as
+@c needed.  However if the change you want to make to this documentation
+@c can be done in an automated way, it's probably easier to change
+@c (generate-documentation) than to make it below and have to deal with
+@c the churn as Prosody updates.
+
+Available @code{prosody-configuration} fields are:
+
+@deftypevr {@code{prosody-configuration} parameter} package prosody
+The Prosody package.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} file-name data-path
+Location of the Prosody data storage directory.  See
+@url{http://prosody.im/doc/configure}.
+Defaults to @samp{"/var/lib/prosody"}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} file-name-list plugin-paths
+Additional plugin directories.  They are searched in all the specified
+paths in order.  See @url{http://prosody.im/doc/plugins_directory}.
+Defaults to @samp{()}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} string-list admins
+This is a list of accounts that are admins for the server.  Note that you
+must create the accounts separately.  See @url{http://prosody.im/doc/admins} and
+@url{http://prosody.im/doc/creating_accounts}.
+Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
+Defaults to @samp{()}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
+Enable use of libevent for better performance under high load.  See
+@url{http://prosody.im/doc/libevent}.
+Defaults to @samp{#f}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
+This is the list of modules Prosody will load on startup.  It looks for
+@code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
+Documentation on modules can be found at: @url{http://prosody.im/doc/modules}.
+Defaults to @samp{%default-modules-enabled}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
+@samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
+should you want to disable them then add them to this list.
+Defaults to @samp{()}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} file-name groups-file
+Path to a text file where the shared groups are defined.  If this path is
+empty then @samp{mod_groups} does nothing.  See
+@url{http://prosody.im/doc/modules/mod_groups}.
+Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
+Disable account creation by default, for security.  See
+@url{http://prosody.im/doc/creating_accounts}.
+Defaults to @samp{#f}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
+These are the SSL/TLS-related settings.  Most of them are disabled so to
+use Prosody's defaults.  If you do not completely understand these options, do
+not add them to your config, it is easy to lower the security of your server
+using them.  See @url{http://prosody.im/doc/advanced_ssl_config}.
+
+Available @code{ssl-configuration} fields are:
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
+This determines what handshake to use.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} file-name key
+Path to your private key file, relative to @code{/etc/prosody}.
+Defaults to @samp{"/etc/prosody/certs/key.pem"}.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} file-name certificate
+Path to your certificate file, relative to @code{/etc/prosody}.
+Defaults to @samp{"/etc/prosody/certs/cert.pem"}.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} file-name capath
+Path to directory containing root certificates that you wish Prosody to
+trust when verifying the certificates of remote servers.
+Defaults to @samp{"/etc/ssl/certs"}.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-file-name cafile
+Path to a file containing root certificates that you wish Prosody to trust.
+Similar to @code{capath} but with all certificates concatenated together.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
+A list of verification options (these mostly map to OpenSSL's
+@code{set_verify()} flags).
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
+A list of general options relating to SSL/TLS.  These map to OpenSSL's
+@code{set_options()}.  For a full list of options available in LuaSec, see the
+LuaSec source.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
+How long a chain of certificate authorities to check when looking for a
+trusted root certificate.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
+An OpenSSL cipher string.  This selects what ciphers Prosody will offer to
+clients, and in what order.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
+A path to a file containing parameters for Diffie-Hellman key exchange.  You
+can create such a file with:
+@code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-string curve
+Curve for Elliptic curve Diffie-Hellman. Prosody's default is
+@samp{"secp384r1"}.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
+A list of "extra" verification options.
+@end deftypevr
+
+@deftypevr {@code{ssl-configuration} parameter} maybe-string password
+Password for encrypted private keys.
+@end deftypevr
+
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
+Whether to force all client-to-server connections to be encrypted or not.
+See @url{http://prosody.im/doc/modules/mod_tls}.
+Defaults to @samp{#f}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
+Whether to force all server-to-server connections to be encrypted or not.
+See @url{http://prosody.im/doc/modules/mod_tls}.
+Defaults to @samp{#f}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
+Whether to require encryption and certificate authentication.  This
+provides ideal security, but requires servers you communicate with to support
+encryption AND present valid, trusted certificates.  See
+@url{http://prosody.im/doc/s2s#security}.
+Defaults to @samp{#f}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
+Many servers don't support encryption or have invalid or self-signed
+certificates.  You can list domains here that will not be required to
+authenticate using certificates.  They will be authenticated using DNS.  See
+@url{http://prosody.im/doc/s2s#security}.
+Defaults to @samp{()}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
+Even if you leave @code{s2s-secure-auth?} disabled, you can still require
+valid certificates for some domains by specifying a list here.  See
+@url{http://prosody.im/doc/s2s#security}.
+Defaults to @samp{()}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} string authentication
+Select the authentication backend to use.  The default provider stores
+passwords in plaintext and uses Prosody's configured data storage to store the
+authentication data.  If you do not trust your server please see
+@url{http://prosody.im/doc/modules/mod_auth_internal_hashed} for information
+about using the hashed backend.  See also
+@url{http://prosody.im/doc/authentication}
+Defaults to @samp{"internal_plain"}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} maybe-string log
+Set logging options.  Advanced logging configuration is not yet supported
+by the GuixSD Prosody Service.  See @url{http://prosody.im/doc/logging}.
+Defaults to @samp{"*syslog"}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} file-name pidfile
+File to write pid in.  See @url{http://prosody.im/doc/modules/mod_posix}.
+Defaults to @samp{"/var/run/prosody/prosody.pid"}.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
+A host in Prosody is a domain on which user accounts can be created.  For
+example if you want your users to have addresses like
+@samp{"john.smith@@example.com"} then you need to add a host
+@samp{"example.com"}.  All options in this list will apply only to this host.
+
+Note: the name "virtual" host is used in configuration to avoid confusion with
+the actual physical host that Prosody is installed on.  A single Prosody
+instance can serve many domains, each one defined as a VirtualHost entry in
+Prosody's configuration.  Conversely a server that hosts a single domain would
+have just one VirtualHost entry.
+
+See @url{http://prosody.im/doc/configure#virtual_host_settings}.
+
+Available @code{virtualhost-configuration} fields are:
+
+all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, plus:
+@deftypevr {@code{virtualhost-configuration} parameter} string domain
+Domain you wish Prosody to serve.
+@end deftypevr
+
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
+Components are extra services on a server which are available to clients,
+usually on a subdomain of the main server (such as
+@samp{"mycomponent.example.com"}).  Example components might be chatroom
+servers, user directories, or gateways to other protocols.
+
+Internal components are implemented with Prosody-specific plugins.  To add an
+internal component, you simply fill the hostname field, and the plugin you wish
+to use for the component.
+
+See @url{http://prosody.im/doc/components}.
+Defaults to @samp{()}.
+
+Available @code{int-component-configuration} fields are:
+
+all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, plus:
+@deftypevr {@code{int-component-configuration} parameter} string hostname
+Hostname of the component.
+@end deftypevr
+
+@deftypevr {@code{int-component-configuration} parameter} string plugin
+Plugin you wish to use for the component.
+@end deftypevr
+
+@deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
+Multi-user chat (MUC) is Prosody's module for allowing you to create
+hosted chatrooms/conferences for XMPP users.
+
+General information on setting up and using MUC chatrooms can be found in our
+"Chatrooms" documentation (@url{http://prosody.im/doc/chatrooms}), which you
+should read if you are new to XMPP chatrooms.
+
+See also @url{http://prosody.im/doc/modules/mod_muc}.
+
+Available @code{mod-muc-configuration} fields are:
+
+@deftypevr {@code{mod-muc-configuration} parameter} string name
+The name to return in service discovery responses.
+Defaults to @samp{"Prosody Chatrooms"}.
+@end deftypevr
+
+@deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
+If @samp{#t}, this will only allow admins to create new chatrooms.
+Otherwise anyone can create a room.  The value @samp{"local"} restricts room
+creation to users on the service's parent domain.  E.g. @samp{user@@example.com}
+can create rooms on @samp{rooms.example.com}.  The value @samp{"admin"}
+restricts to service administrators only.
+Defaults to @samp{#f}.
+@end deftypevr
+
+@deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
+Maximum number of history messages that will be sent to the member that has
+just joined the room.
+Defaults to @samp{20}.
+@end deftypevr
+
+@end deftypevr
+
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
+External components use XEP-0114, which most standalone components
+support.  To add an external component, you simply fill the hostname field.  See
+@url{http://prosody.im/doc/components}.
+Defaults to @samp{()}.
+
+Available @code{ext-component-configuration} fields are:
+
+all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, plus:
+@deftypevr {@code{ext-component-configuration} parameter} string component-secret
+Password which the component will use to log in.
+@end deftypevr
+
+@deftypevr {@code{ext-component-configuration} parameter} string hostname
+Hostname of the component.
+@end deftypevr
+
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
+Port(s) Prosody listens on for component connections.
+@end deftypevr
+
+@deftypevr {@code{prosody-configuration} parameter} string component-interface
+Interface Prosody listens on for component connections.
+Defaults to @samp{"127.0.0.1"}.
+@end deftypevr
+
+It could be that you just want to get a @code{prosody.cfg.lua}
+up and running.  In that case, you can pass an
+@code{opaque-prosody-configuration} record as the value of
+@code{prosody-service-type}.  As its name indicates, an opaque configuration
+does not have easy reflective capabilities.
+Available @code{opaque-prosody-configuration} fields are:
+
+@deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
+The prosody package.
+@end deftypevr
+
+@deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
+The contents of the @code{prosody.cfg.lua} to use.
+@end deftypevr
+
+For example, if your @code{prosody.cfg.lua} is just the empty
+string, you could instantiate a prosody service like this:
+
+@example
+(service prosody-service-type
+         (opaque-prosody-configuration
+          (prosody.cfg.lua "")))
+@end example
+
 @node Kerberos Services
 @subsubsection Kerberos Services
 @cindex Kerberos
diff --git a/gnu/local.mk b/gnu/local.mk
index 2e714ac28..86aad8e76 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -414,6 +414,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/services/lirc.scm				\
   %D%/services/mail.scm				\
   %D%/services/mcron.scm			\
+  %D%/services/messaging.scm			\
   %D%/services/networking.scm			\
   %D%/services/nfs.scm			\
   %D%/services/shepherd.scm			\
diff --git a/gnu/packages/messaging.scm b/gnu/packages/messaging.scm
index 95c265b98..6f1025d36 100644
--- a/gnu/packages/messaging.scm
+++ b/gnu/packages/messaging.scm
@@ -7,7 +7,7 @@
 ;;; Copyright © 2015 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2016 ng0 <ng0@libertad.pw>
 ;;; Copyright © 2016 Andy Patterson <ajpatter@uwaterloo.ca>
-;;; Copyright © 2016 Clément Lassieur <clement@lassieur.org>
+;;; Copyright © 2016, 2017 Clément Lassieur <clement@lassieur.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -39,6 +39,7 @@
   #:use-module (gnu packages aidc)
   #:use-module (gnu packages autotools)
   #:use-module (gnu packages avahi)
+  #:use-module (gnu packages base)
   #:use-module (gnu packages check)
   #:use-module (gnu packages crypto)
   #:use-module (gnu packages cyrus-sasl)
@@ -535,6 +536,14 @@ end-to-end encryption support; XML console.")
              (substitute* "configure"
                (("exit 1") ""))
              #t))
+         (add-after 'unpack 'fix-makefile
+           (lambda _
+             (substitute* "Makefile"
+               ;; prosodyctl needs to read the configuration file.
+               (("^INSTALLEDCONFIG =.*") "INSTALLEDCONFIG = /etc/prosody\n")
+               ;; prosodyctl needs a place to put auto-generated certificates.
+               (("^INSTALLEDDATA =.*") "INSTALLEDDATA = /var/lib/prosody\n"))
+             #t))
          (add-after 'install 'wrap-programs
            (lambda* (#:key inputs outputs #:allow-other-keys)
              ;; Make sure all executables in "bin" find the required Lua
@@ -546,27 +555,36 @@ end-to-end encryption support; XML console.")
                                               (if (string-prefix? "lua" label)
                                                   directory #f)))
                                            inputs)))
-                    (path  (string-join
-                            (map (lambda (path)
-                                   (string-append path "/share/lua/5.1/?.lua;"
-                                                  path "/share/lua/5.1/?/?.lua"))
-                                 (cons out deps))
-                            ";"))
-                    (cpath (string-join
-                            (map (lambda (path)
-                                   (string-append path "/lib/lua/5.1/?.so;"
-                                                  path "/lib/lua/5.1/?/?.so"))
-                                 (cons out deps))
-                            ";")))
+                    (lua-path (string-join
+                               (map (lambda (path)
+                                      (string-append
+                                       path "/share/lua/5.1/?.lua;"
+                                       path "/share/lua/5.1/?/?.lua"))
+                                    (cons out deps))
+                               ";"))
+                    (lua-cpath (string-join
+                                (map (lambda (path)
+                                       (string-append
+                                        path "/lib/lua/5.1/?.so;"
+                                        path "/lib/lua/5.1/?/?.so"))
+                                     (cons out deps))
+                                ";"))
+                    (openssl (assoc-ref inputs "openssl"))
+                    (coreutils (assoc-ref inputs "coreutils"))
+                    (path (map (lambda (dir)
+                                 (string-append dir "/bin"))
+                               (list openssl coreutils))))
                (for-each (lambda (file)
                            (wrap-program file
-                             `("LUA_PATH"  ";" = (,path))
-                             `("LUA_CPATH" ";" = (,cpath))))
+                             `("LUA_PATH"  ";" = (,lua-path))
+                             `("LUA_CPATH" ";" = (,lua-cpath))
+                             `("PATH" ":" prefix ,path)))
                          (find-files bin ".*"))
                #t))))))
     (inputs
      `(("libidn" ,libidn)
        ("openssl" ,openssl)
+       ("coreutils" ,coreutils) ; For chmod in certificate generation.
        ("lua" ,lua-5.1)
        ("lua5.1-expat" ,lua5.1-expat)
        ("lua5.1-socket" ,lua5.1-socket)
diff --git a/gnu/services/configuration.scm b/gnu/services/configuration.scm
index 94c5f2155..a98db64fa 100644
--- a/gnu/services/configuration.scm
+++ b/gnu/services/configuration.scm
@@ -28,10 +28,13 @@
   #:use-module (srfi srfi-35)
   #:export (configuration-field
             configuration-field-name
+            configuration-field-type
             configuration-missing-field
             configuration-field-error
             configuration-field-serializer
             configuration-field-getter
+            configuration-field-default-value-thunk
+            configuration-field-documentation
             serialize-configuration
             define-configuration
             validate-configuration
diff --git a/gnu/services/messaging.scm b/gnu/services/messaging.scm
new file mode 100644
index 000000000..833b64514
--- /dev/null
+++ b/gnu/services/messaging.scm
@@ -0,0 +1,728 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu services messaging)
+  #:use-module (gnu packages messaging)
+  #:use-module (gnu packages admin)
+  #:use-module (gnu services)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu services configuration)
+  #:use-module (gnu system shadow)
+  #:use-module (guix gexp)
+  #:use-module (guix records)
+  #:use-module (guix packages)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-35)
+  #:use-module (ice-9 match)
+  #:export (prosody-service-type
+            prosody-configuration
+            opaque-prosody-configuration
+
+            virtualhost-configuration
+            int-component-configuration
+            ext-component-configuration
+
+            mod-muc-configuration
+            ssl-configuration
+
+            %default-modules-enabled))
+
+;;; Commentary:
+;;;
+;;; Messaging services.
+;;;
+;;; Code:
+
+(define (id ctx . parts)
+  (datum->syntax ctx (apply symbol-append (map syntax->datum parts))))
+
+(define-syntax define-maybe
+  (lambda (x)
+    (syntax-case x ()
+      ((_ stem)
+       (with-syntax
+           ((stem?                (id #'stem #'stem #'?))
+            (maybe-stem?          (id #'stem #'maybe- #'stem #'?))
+            (serialize-stem       (id #'stem #'serialize- #'stem))
+            (serialize-maybe-stem (id #'stem #'serialize-maybe- #'stem)))
+         #'(begin
+             (define (maybe-stem? val)
+               (or (eq? val 'disabled) (stem? val)))
+             (define (serialize-maybe-stem field-name val)
+               (when (stem? val) (serialize-stem field-name val)))))))))
+
+(define-syntax define-all-configurations
+  (lambda (stx)
+    (define (make-pred arg)
+      (lambda (field target)
+        (and (memq (syntax->datum target) `(common ,arg)) field)))
+    (syntax-case stx ()
+      ((_ stem (field (field-type def) doc target) ...)
+       (with-syntax (((new-field-type ...)
+                      (map (lambda (field-type target)
+                             (if (and (eq? 'common (syntax->datum target))
+                                      (not (string-prefix?
+                                            "maybe-"
+                                            (symbol->string
+                                             (syntax->datum field-type)))))
+                                 (id #'stem #'maybe- field-type) field-type))
+                           #'(field-type ...) #'(target ...)))
+                     ((new-def ...)
+                      (map (lambda (def target)
+                             (if (eq? 'common (syntax->datum target))
+                                 #''disabled def))
+                           #'(def ...) #'(target ...)))
+                     ((new-doc ...)
+                      (map (lambda (doc target)
+                             (if (eq? 'common (syntax->datum target))
+                                 "" doc))
+                           #'(doc ...) #'(target ...))))
+         #`(begin
+             (define common-fields
+               '(#,@(filter-map (make-pred #f) #'(field ...) #'(target ...))))
+             (define-configuration prosody-configuration
+               #,@(filter-map (make-pred 'global)
+                              #'((field (field-type def) doc) ...)
+                              #'(target ...)))
+             (define-configuration virtualhost-configuration
+               #,@(filter-map (make-pred 'virtualhost)
+                              #'((field (new-field-type new-def) new-doc) ...)
+                              #'(target ...)))
+             (define-configuration int-component-configuration
+               #,@(filter-map (make-pred 'int-component)
+                              #'((field (new-field-type new-def) new-doc) ...)
+                              #'(target ...)))
+             (define-configuration ext-component-configuration
+               #,@(filter-map (make-pred 'ext-component)
+                              #'((field (new-field-type new-def) new-doc) ...)
+                              #'(target ...)))))))))
+
+(define (uglify-field-name field-name)
+  (let ((str (symbol->string field-name)))
+    (string-join (string-split (if (string-suffix? "?" str)
+                                   (substring str 0 (1- (string-length str)))
+                                   str)
+                               #\-)
+                 "_")))
+
+(define (serialize-field field-name val)
+  (format #t "~a = ~a;\n" (uglify-field-name field-name) val))
+(define (serialize-field-list field-name val)
+  (serialize-field field-name
+                   (with-output-to-string
+                     (lambda ()
+                       (format #t "{\n")
+                       (for-each (lambda (x)
+                                   (format #t "~a;\n" x))
+                                 val)
+                       (format #t "}")))))
+
+(define (serialize-boolean field-name val)
+  (serialize-field field-name (if val "true" "false")))
+(define-maybe boolean)
+
+(define (string-or-boolean? val)
+  (or (string? val) (boolean? val)))
+(define (serialize-string-or-boolean field-name val)
+  (if (string? val)
+      (serialize-string field-name val)
+      (serialize-boolean field-name val)))
+
+(define (non-negative-integer? val)
+  (and (exact-integer? val) (not (negative? val))))
+(define (serialize-non-negative-integer field-name val)
+  (serialize-field field-name val))
+(define-maybe non-negative-integer)
+
+(define (non-negative-integer-list? val)
+  (and (list? val) (and-map non-negative-integer? val)))
+(define (serialize-non-negative-integer-list field-name val)
+  (serialize-field-list field-name val))
+(define-maybe non-negative-integer-list)
+
+(define (enclose-quotes s)
+  (format #f "\"~a\"" s))
+(define (serialize-string field-name val)
+  (serialize-field field-name (enclose-quotes val)))
+(define-maybe string)
+
+(define (string-list? val)
+  (and (list? val)
+       (and-map (lambda (x)
+                  (and (string? x) (not (string-index x #\,))))
+                val)))
+(define (serialize-string-list field-name val)
+  (serialize-field-list field-name (map enclose-quotes val)))
+(define-maybe string-list)
+
+(define (module-list? val)
+  (string-list? val))
+(define (serialize-module-list field-name val)
+  (serialize-string-list field-name (cons "posix" val)))
+(define-maybe module-list)
+
+(define (file-name? val)
+  (and (string? val)
+       (string-prefix? "/" val)))
+(define (serialize-file-name field-name val)
+  (serialize-string field-name val))
+(define-maybe file-name)
+
+(define (file-name-list? val)
+  (and (list? val) (and-map file-name? val)))
+(define (serialize-file-name-list field-name val)
+  (serialize-string-list field-name val))
+(define-maybe file-name)
+
+(define-configuration mod-muc-configuration
+  (name
+   (string "Prosody Chatrooms")
+   "The name to return in service discovery responses.")
+
+  (restrict-room-creation
+   (string-or-boolean #f)
+   "If @samp{#t}, this will only allow admins to create new chatrooms.
+Otherwise anyone can create a room.  The value @samp{\"local\"} restricts room
+creation to users on the service's parent domain.  E.g. @samp{user@@example.com}
+can create rooms on @samp{rooms.example.com}.  The value @samp{\"admin\"}
+restricts to service administrators only.")
+
+  (max-history-messages
+   (non-negative-integer 20)
+   "Maximum number of history messages that will be sent to the member that has
+just joined the room."))
+(define (serialize-mod-muc-configuration field-name val)
+  (serialize-configuration val mod-muc-configuration-fields))
+(define-maybe mod-muc-configuration)
+
+(define-configuration ssl-configuration
+  (protocol
+   (maybe-string 'disabled)
+   "This determines what handshake to use.")
+
+  (key
+   (file-name "/etc/prosody/certs/key.pem")
+   "Path to your private key file, relative to @code{/etc/prosody}.")
+
+  (certificate
+   (file-name "/etc/prosody/certs/cert.pem")
+   "Path to your certificate file, relative to @code{/etc/prosody}.")
+
+  (capath
+   (file-name "/etc/ssl/certs")
+   "Path to directory containing root certificates that you wish Prosody to
+trust when verifying the certificates of remote servers.")
+
+  (cafile
+   (maybe-file-name 'disabled)
+   "Path to a file containing root certificates that you wish Prosody to trust.
+Similar to @code{capath} but with all certificates concatenated together.")
+
+  (verify
+   (maybe-string-list 'disabled)
+   "A list of verification options (these mostly map to OpenSSL's
+@code{set_verify()} flags).")
+
+  (options
+   (maybe-string-list 'disabled)
+   "A list of general options relating to SSL/TLS.  These map to OpenSSL's
+@code{set_options()}.  For a full list of options available in LuaSec, see the
+LuaSec source.")
+
+  (depth
+   (maybe-non-negative-integer 'disabled)
+   "How long a chain of certificate authorities to check when looking for a
+trusted root certificate.")
+
+  (ciphers
+   (maybe-string 'disabled)
+   "An OpenSSL cipher string.  This selects what ciphers Prosody will offer to
+clients, and in what order.")
+
+  (dhparam
+   (maybe-file-name 'disabled)
+   "A path to a file containing parameters for Diffie-Hellman key exchange.  You
+can create such a file with:
+@code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}")
+
+  (curve
+   (maybe-string 'disabled)
+   "Curve for Elliptic curve Diffie-Hellman. Prosody's default is
+@samp{\"secp384r1\"}.")
+
+  (verifyext
+   (maybe-string-list 'disabled)
+   "A list of \"extra\" verification options.")
+
+  (password
+   (maybe-string 'disabled)
+   "Password for encrypted private keys."))
+(define (serialize-ssl-configuration field-name val)
+  (format #t "ssl = {\n")
+  (serialize-configuration val ssl-configuration-fields)
+  (format #t "};\n"))
+(define-maybe ssl-configuration)
+
+(define %default-modules-enabled
+  '("roster"
+    "saslauth"
+    "tls"
+    "dialback"
+    "disco"
+    "private"
+    "vcard"
+    "version"
+    "uptime"
+    "time"
+    "ping"
+    "pep"
+    "register"
+    "admin_adhoc"))
+
+;; Guile bug.  Use begin wrapper, because otherwise virtualhost-configuration
+;; is assumed to be a function.  See
+;; https://www.gnu.org/software/guile/manual/html_node/R6RS-Incompatibilities.html
+(begin
+  (define (virtualhost-configuration-list? val)
+    (and (list? val) (and-map virtualhost-configuration? val)))
+  (define (serialize-virtualhost-configuration-list l)
+    (for-each
+     (lambda (val) (serialize-virtualhost-configuration val)) l))
+
+  (define (int-component-configuration-list? val)
+    (and (list? val) (and-map int-component-configuration? val)))
+  (define (serialize-int-component-configuration-list l)
+    (for-each
+     (lambda (val) (serialize-int-component-configuration val)) l))
+
+  (define (ext-component-configuration-list? val)
+    (and (list? val) (and-map ext-component-configuration? val)))
+  (define (serialize-ext-component-configuration-list l)
+    (for-each
+     (lambda (val) (serialize-ext-component-configuration val)) l))
+
+  (define-all-configurations prosody-configuration
+    (prosody
+     (package prosody)
+     "The Prosody package."
+     global)
+
+    (data-path
+     (file-name "/var/lib/prosody")
+     "Location of the Prosody data storage directory.  See
+@url{http://prosody.im/doc/configure}."
+     global)
+
+    (plugin-paths
+     (file-name-list '())
+     "Additional plugin directories.  They are searched in all the specified
+paths in order.  See @url{http://prosody.im/doc/plugins_directory}."
+     global)
+
+    (admins
+     (string-list '())
+     "This is a list of accounts that are admins for the server.  Note that you
+must create the accounts separately.  See @url{http://prosody.im/doc/admins} and
+@url{http://prosody.im/doc/creating_accounts}.
+Example: @code{(admins '(\"user1@@example.com\" \"user2@@example.net\"))}"
+     common)
+
+    (use-libevent?
+     (boolean #f)
+     "Enable use of libevent for better performance under high load.  See
+@url{http://prosody.im/doc/libevent}."
+     common)
+
+    (modules-enabled
+     (module-list %default-modules-enabled)
+     "This is the list of modules Prosody will load on startup.  It looks for
+@code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
+Documentation on modules can be found at: @url{http://prosody.im/doc/modules}.
+Defaults to @samp{%default-modules-enabled}."
+     common)
+
+    (modules-disabled
+     (string-list '())
+     "@samp{\"offline\"}, @samp{\"c2s\"} and @samp{\"s2s\"} are auto-loaded, but
+should you want to disable them then add them to this list."
+     common)
+
+    (groups-file
+     (file-name "/var/lib/prosody/sharedgroups.txt")
+     "Path to a text file where the shared groups are defined.  If this path is
+empty then @samp{mod_groups} does nothing.  See
+@url{http://prosody.im/doc/modules/mod_groups}."
+     common)
+
+    (allow-registration?
+     (boolean #f)
+     "Disable account creation by default, for security.  See
+@url{http://prosody.im/doc/creating_accounts}."
+     common)
+
+    (ssl
+     (maybe-ssl-configuration (ssl-configuration))
+     "These are the SSL/TLS-related settings.  Most of them are disabled so to
+use Prosody's defaults.  If you do not completely understand these options, do
+not add them to your config, it is easy to lower the security of your server
+using them.  See @url{http://prosody.im/doc/advanced_ssl_config}."
+     common)
+
+    (c2s-require-encryption?
+     (boolean #f)
+     "Whether to force all client-to-server connections to be encrypted or not.
+See @url{http://prosody.im/doc/modules/mod_tls}."
+     common)
+
+    (s2s-require-encryption?
+     (boolean #f)
+     "Whether to force all server-to-server connections to be encrypted or not.
+See @url{http://prosody.im/doc/modules/mod_tls}."
+     common)
+
+    (s2s-secure-auth?
+     (boolean #f)
+     "Whether to require encryption and certificate authentication.  This
+provides ideal security, but requires servers you communicate with to support
+encryption AND present valid, trusted certificates.  See
+@url{http://prosody.im/doc/s2s#security}."
+     common)
+
+    (s2s-insecure-domains
+     (string-list '())
+     "Many servers don't support encryption or have invalid or self-signed
+certificates.  You can list domains here that will not be required to
+authenticate using certificates.  They will be authenticated using DNS.  See
+@url{http://prosody.im/doc/s2s#security}."
+     common)
+
+    (s2s-secure-domains
+     (string-list '())
+     "Even if you leave @code{s2s-secure-auth?} disabled, you can still require
+valid certificates for some domains by specifying a list here.  See
+@url{http://prosody.im/doc/s2s#security}."
+     common)
+
+    (authentication
+     (string "internal_plain")
+     "Select the authentication backend to use.  The default provider stores
+passwords in plaintext and uses Prosody's configured data storage to store the
+authentication data.  If you do not trust your server please see
+@url{http://prosody.im/doc/modules/mod_auth_internal_hashed} for information
+about using the hashed backend.  See also
+@url{http://prosody.im/doc/authentication}"
+     common)
+
+    ;; TODO: Handle more complicated log structures.
+    (log
+     (maybe-string "*syslog")
+     "Set logging options.  Advanced logging configuration is not yet supported
+by the GuixSD Prosody Service.  See @url{http://prosody.im/doc/logging}."
+     common)
+
+    (pidfile
+     (file-name "/var/run/prosody/prosody.pid")
+     "File to write pid in.  See @url{http://prosody.im/doc/modules/mod_posix}."
+     global)
+
+    (virtualhosts
+     (virtualhost-configuration-list
+      (list (virtualhost-configuration
+             (domain "localhost"))))
+     "A host in Prosody is a domain on which user accounts can be created.  For
+example if you want your users to have addresses like
+@samp{\"john.smith@@example.com\"} then you need to add a host
+@samp{\"example.com\"}.  All options in this list will apply only to this host.
+
+Note: the name \"virtual\" host is used in configuration to avoid confusion with
+the actual physical host that Prosody is installed on.  A single Prosody
+instance can serve many domains, each one defined as a VirtualHost entry in
+Prosody's configuration.  Conversely a server that hosts a single domain would
+have just one VirtualHost entry.
+
+See @url{http://prosody.im/doc/configure#virtual_host_settings}."
+     global)
+
+    (int-components
+     (int-component-configuration-list '())
+     "Components are extra services on a server which are available to clients,
+usually on a subdomain of the main server (such as
+@samp{\"mycomponent.example.com\"}).  Example components might be chatroom
+servers, user directories, or gateways to other protocols.
+
+Internal components are implemented with Prosody-specific plugins.  To add an
+internal component, you simply fill the hostname field, and the plugin you wish
+to use for the component.
+
+See @url{http://prosody.im/doc/components}."
+     global)
+
+    (ext-components
+     (ext-component-configuration-list '())
+     "External components use XEP-0114, which most standalone components
+support.  To add an external component, you simply fill the hostname field.  See
+@url{http://prosody.im/doc/components}."
+     global)
+
+    (component-secret
+     (string (configuration-missing-field 'ext-component 'component-secret))
+     "Password which the component will use to log in."
+     ext-component)
+
+    (component-ports
+     (non-negative-integer-list '(5347))
+     "Port(s) Prosody listens on for component connections."
+     global)
+
+    (component-interface
+     (string "127.0.0.1")
+     "Interface Prosody listens on for component connections."
+     global)
+
+    (domain
+     (string (configuration-missing-field 'virtualhost 'domain))
+     "Domain you wish Prosody to serve."
+     virtualhost)
+
+    (hostname
+     (string (configuration-missing-field 'int-component 'hostname))
+     "Hostname of the component."
+     int-component)
+
+    (plugin
+     (string (configuration-missing-field 'int-component 'plugin))
+     "Plugin you wish to use for the component."
+     int-component)
+
+    (mod-muc
+     (maybe-mod-muc-configuration 'disabled)
+     "Multi-user chat (MUC) is Prosody's module for allowing you to create
+hosted chatrooms/conferences for XMPP users.
+
+General information on setting up and using MUC chatrooms can be found in our
+\"Chatrooms\" documentation (@url{http://prosody.im/doc/chatrooms}), which you
+should read if you are new to XMPP chatrooms.
+
+See also @url{http://prosody.im/doc/modules/mod_muc}."
+     int-component)
+
+    (hostname
+     (string (configuration-missing-field 'ext-component 'hostname))
+     "Hostname of the component."
+     ext-component)))
+
+;; Serialize Virtualhost line first.
+(define (serialize-virtualhost-configuration config)
+  (define (rest? field)
+    (not (memq (configuration-field-name field)
+               '(domain))))
+  (let ((domain (virtualhost-configuration-domain config))
+        (rest (filter rest? virtualhost-configuration-fields)))
+    (format #t "VirtualHost \"~a\"\n" domain)
+    (serialize-configuration config rest)))
+
+;; Serialize Component line first.
+(define (serialize-int-component-configuration config)
+  (define (rest? field)
+    (not (memq (configuration-field-name field)
+               '(hostname plugin))))
+  (let ((hostname (int-component-configuration-hostname config))
+        (plugin (int-component-configuration-plugin config))
+        (rest (filter rest? int-component-configuration-fields)))
+    (format #t "Component \"~a\" \"~a\"\n" hostname plugin)
+    (serialize-configuration config rest)))
+
+;; Serialize Component line first.
+(define (serialize-ext-component-configuration config)
+  (define (rest? field)
+    (not (memq (configuration-field-name field)
+               '(hostname))))
+  (let ((hostname (ext-component-configuration-hostname config))
+        (rest (filter rest? ext-component-configuration-fields)))
+    (format #t "Component \"~a\"\n" hostname)
+    (serialize-configuration config rest)))
+
+;; Serialize virtualhosts and components last.
+(define (serialize-prosody-configuration config)
+  (define (rest? field)
+    (not (memq (configuration-field-name field)
+               '(virtualhosts int-components ext-components))))
+  (let ((rest (filter rest? prosody-configuration-fields)))
+    (serialize-configuration config rest))
+  (serialize-virtualhost-configuration-list
+   (prosody-configuration-virtualhosts config))
+  (serialize-int-component-configuration-list
+   (prosody-configuration-int-components config))
+  (serialize-ext-component-configuration-list
+   (prosody-configuration-ext-components config)))
+
+(define-configuration opaque-prosody-configuration
+  (prosody
+   (package prosody)
+   "The prosody package.")
+
+  (prosody.cfg.lua
+   (string (configuration-missing-field 'opaque-prosody-configuration
+                                        'prosody.cfg.lua))
+   "The contents of the @code{prosody.cfg.lua} to use."))
+
+(define (prosody-shepherd-service config)
+  "Return a <shepherd-service> for Prosody with CONFIG."
+  (let* ((prosody (if (opaque-prosody-configuration? config)
+                      (opaque-prosody-configuration-prosody config)
+                      (prosody-configuration-prosody config)))
+         (prosodyctl-bin (file-append prosody "/bin/prosodyctl"))
+         (prosodyctl-action (lambda args
+                              #~(lambda _
+                                  (zero? (system* #$prosodyctl-bin #$@args))))))
+    (list (shepherd-service
+           (documentation "Run the Prosody XMPP server")
+           (provision '(prosody))
+           (requirement '(networking syslogd user-processes))
+           (start (prosodyctl-action "start"))
+           (stop (prosodyctl-action "stop"))))))
+
+(define %prosody-accounts
+  (list (user-group (name "prosody") (system? #t))
+        (user-account
+         (name "prosody")
+         (group "prosody")
+         (system? #t)
+         (comment "Prosody daemon user")
+         (home-directory "/var/empty")
+         (shell (file-append shadow "/sbin/nologin")))))
+
+(define (prosody-activation config)
+  "Return the activation gexp for CONFIG."
+  (let* ((config-dir "/etc/prosody")
+         (default-certs-dir "/etc/prosody/certs")
+         (data-path (prosody-configuration-data-path config))
+         (pidfile-dir (dirname (prosody-configuration-pidfile config)))
+         (config-str
+          (if (opaque-prosody-configuration? config)
+              (opaque-prosody-configuration-prosody.cfg.lua config)
+              (with-output-to-string
+                (lambda ()
+                  (serialize-prosody-configuration config)))))
+         (config-file (plain-file "prosody.cfg.lua" config-str)))
+    #~(begin
+        (define %user (getpw "prosody"))
+
+        (mkdir-p #$config-dir)
+        (chown #$config-dir (passwd:uid %user) (passwd:gid %user))
+        (copy-file #$config-file (string-append #$config-dir
+                                                "/prosody.cfg.lua"))
+
+        (mkdir-p #$default-certs-dir)
+        (chown #$default-certs-dir (passwd:uid %user) (passwd:gid %user))
+        (chmod #$default-certs-dir #o750)
+
+        (mkdir-p #$data-path)
+        (chown #$data-path (passwd:uid %user) (passwd:gid %user))
+        (chmod #$data-path #o750)
+
+        (mkdir-p #$pidfile-dir)
+        (chown #$pidfile-dir (passwd:uid %user) (passwd:gid %user)))))
+
+(define prosody-service-type
+  (service-type (name 'prosody)
+                (extensions
+                 (list (service-extension shepherd-root-service-type
+                                          prosody-shepherd-service)
+                       (service-extension account-service-type
+                                          (const %prosody-accounts))
+                       (service-extension activation-service-type
+                                          prosody-activation)))))
+
+;; A little helper to make it easier to document all those fields.
+(define (generate-documentation)
+  (define documentation
+    `((prosody-configuration
+       ,prosody-configuration-fields
+       (ssl ssl-configuration)
+       (virtualhosts virtualhost-configuration)
+       (int-components int-component-configuration)
+       (ext-components ext-component-configuration))
+      (ssl-configuration ,ssl-configuration-fields)
+      (int-component-configuration ,int-component-configuration-fields
+                                   (mod-muc mod-muc-configuration))
+      (ext-component-configuration ,ext-component-configuration-fields)
+      (mod-muc-configuration ,mod-muc-configuration-fields)
+      (virtualhost-configuration ,virtualhost-configuration-fields)
+      (opaque-prosody-configuration ,opaque-prosody-configuration-fields)))
+  (define (generate configuration-name)
+    (match (assq-ref documentation configuration-name)
+      ((fields . sub-documentation)
+       (format #t "\nAvailable @code{~a} fields are:\n\n" configuration-name)
+       (when (memq configuration-name
+                   '(virtualhost-configuration
+                     int-component-configuration
+                     ext-component-configuration))
+         (format #t "all these @code{prosody-configuration} fields: ~a, plus:\n"
+                 (string-join (map (lambda (s)
+                                     (format #f "@code{~a}" s)) common-fields)
+                              ", ")))
+       (for-each
+        (lambda (f)
+          (let ((field-name (configuration-field-name f))
+                (field-type (configuration-field-type f))
+                (field-docs (string-trim-both
+                             (configuration-field-documentation f)))
+                (default (catch #t
+                           (configuration-field-default-value-thunk f)
+                           (lambda _ 'nope))))
+            (define (escape-chars str chars escape)
+              (with-output-to-string
+                (lambda ()
+                  (string-for-each (lambda (c)
+                                     (when (char-set-contains? chars c)
+                                       (display escape))
+                                     (display c))
+                                   str))))
+            (define (show-default? val)
+              (or (string? default) (number? default) (boolean? default)
+                  (and (list? val) (and-map show-default? val))))
+            (format #t "@deftypevr {@code{~a} parameter} ~a ~a\n~a\n"
+                    configuration-name field-type field-name field-docs)
+            (when (show-default? default)
+              (format #t "Defaults to @samp{~a}.\n"
+                      (escape-chars (format #f "~s" default)
+                                    (char-set #\@ #\{ #\})
+                                    #\@)))
+            (for-each generate (or (assq-ref sub-documentation field-name) '()))
+            (format #t "@end deftypevr\n\n")))
+        (filter (lambda (f)
+                  (not (string=? "" (configuration-field-documentation f))))
+                fields)))))
+  (generate 'prosody-configuration)
+  (format #t "It could be that you just want to get a @code{prosody.cfg.lua}
+up and running.  In that case, you can pass an
+@code{opaque-prosody-configuration} record as the value of
+@code{prosody-service-type}.  As its name indicates, an opaque configuration
+does not have easy reflective capabilities.")
+  (generate 'opaque-prosody-configuration)
+  (format #t "For example, if your @code{prosody.cfg.lua} is just the empty
+string, you could instantiate a prosody service like this:
+
+@example
+(service prosody-service-type
+         (opaque-prosody-configuration
+          (prosody.cfg.lua \"\")))
+@end example"))
+
+;;; messaging.scm ends here
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 19+ messages in thread
* RFH: Add prosody service
@ 2016-11-26 17:15 Clément Lassieur
  2016-11-26 17:20 ` [PATCH] gnu: " Clément Lassieur
                   ` (3 more replies)
  0 siblings, 4 replies; 19+ messages in thread
From: Clément Lassieur @ 2016-11-26 17:15 UTC (permalink / raw)
  To: guix-devel

Hello,

I'm actually working on the Prosody service, and I am struggling with a
few things.  What I did works, but some configurations are probably
missing.  I'm not sure I'm doing it the right way, so I would appreciate
a few comments before I go further.

Here is how a typical .lua Prosody configuration file looks like:

-- global section --

global-1 = ...
global-2 = ...
common-1 = ...
common-2 = ...
common-3 = ...

-- virtualhosts section --

Virtualhost domain1
  common-1 = ...
  common-2 = ...
  common-3 = ...

Virtualhost domain2
  common-1 = ...
  common-2 = ...
  common-3 = ...

Settings that are in the global section apply to all virtualhosts.
Settings under each Virtualhost entry apply only to that virtualhost.

So in Scheme, I implemented this as a prosody-configuration
(representing the whole file), containing:
  - global settings,
  - common settings,
  - a list of virtualhost-configuration.

Here are my problems.

A. A virtualhost-configuration has a lot in common with
   prosody-configuration, and I don't want to repeat stuff.

B. Common settings should have a default value in prosody-configuration,
   and be disabled by default in the list of virtualhost-configurations.

I found two ways to solve this:

1. One uses "eval" to transform the input of "define-configuration" into
   a list that I can build from other lists.

2. The other uses a macro that takes define-configuration's input, plus
   a tag (called target) describing whether it's a global, common, or
   virtualhost specific field.  Then the macro calls
   define-configuration many times, each time with a subset of the
   original input, filtered with a specific tag ("global",
   "virtualhost") plus the "common" tag.
   (Its name is define-all-configurations.)

I prefer the first one because it is more readable, but I have been said
in this thread:
http://lists.gnu.org/archive/html/guix-devel/2016-11/msg00993.html
that it is bad programming style.

So I will send two patches, one with the first way and the other with
the second way.  Maybe none of them will be good, don't hesitate to tell
me.  I'm willing to do any changes you'll want.

I did not talk about Components so to simplify things, but its quite
like a Virtualhost, in that it can have common settings too.

There's another issue: how to represent fields that we don't want to
serialize (see problem B).  I define a macro (define-maybe) that adds to
a field the possibility to have the value 'disabled.  But there are
plenty of other ways to do, I could do differently, just tell me.  There
is this thread talking about it:
http://lists.gnu.org/archive/html/guix-devel/2016-11/msg01024.html.

-- 
Clément Lassieur

^ permalink raw reply	[flat|nested] 19+ messages in thread
end of thread, other threads:[~2017-01-08 22:40 UTC | newest]

Thread overview: 19+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-04 21:55 [PATCH] gnu: Add Prosody service Clément Lassieur
2017-01-05 10:34 ` Hartmut Goebel
2017-01-05 10:50   ` ng0
2017-01-07 22:10     ` Clément Lassieur
2017-01-07 21:14   ` Clément Lassieur
2017-01-07 21:29 ` Ludovic Courtès
2017-01-08 19:06   ` Clément Lassieur
2017-01-08 19:08     ` [PATCH 1/3] " Clément Lassieur
2017-01-08 19:08       ` [PATCH 2/3] gnu: prosody: Fix inputs Clément Lassieur
2017-01-08 22:38         ` Ludovic Courtès
2017-01-08 19:08       ` [PATCH 3/3] gnu: prosody: Make config and data files visible to 'prosodyctl' Clément Lassieur
2017-01-08 22:38         ` Ludovic Courtès
2017-01-08 22:40       ` [PATCH 1/3] gnu: Add Prosody service Ludovic Courtès
  -- strict thread matches above, loose matches on Subject: below --
2016-11-26 17:15 RFH: Add prosody service Clément Lassieur
2016-11-26 17:20 ` [PATCH] gnu: " Clément Lassieur
2016-11-26 23:41   ` Leo Famulari
2016-11-27 10:04     ` Clément Lassieur
2016-11-26 17:20 ` Clément Lassieur
2016-11-26 21:28 ` Clément Lassieur
2016-11-26 21:30 ` Clément Lassieur

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