services: prosody: Allow to add raw content to the config file.

* doc/guix.texi (Messaging Services): Update accordingly.
* gnu/services/messaging.scm (prosody-configuration)[raw-content]: New field.
(raw-content?, serialize-raw-content): New procedures.

doc/guix.texi

@@ -14170,7 +14170,7 @@ 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}, @code{http-max-content-size}, @code{http-external-url}, plus:
+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}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
 @deftypevr {@code{virtualhost-configuration} parameter} string domain
 Domain you wish Prosody to serve.
 @end deftypevr
@@ -14192,7 +14192,7 @@ 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}, @code{http-max-content-size}, @code{http-external-url}, plus:
+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}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
 @deftypevr {@code{int-component-configuration} parameter} string hostname
 Hostname of the component.
 @end deftypevr
@@ -14245,7 +14245,7 @@ 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}, @code{http-max-content-size}, @code{http-external-url}, plus:
+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}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
 Password which the component will use to log in.
 @end deftypevr
@@ -14265,6 +14265,10 @@ Interface Prosody listens on for component connections.
 Defaults to @samp{"127.0.0.1"}.
 @end deftypevr
 
+@deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
+Raw content that will be added to the configuration file.
+@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

gnu/services/messaging.scm

@@ -176,6 +176,12 @@
   (serialize-string-list field-name val))
 (define-maybe file-name)
 
+(define (raw-content? val)
+  (not (eq? val 'disabled)))
+(define (serialize-raw-content field-name val)
+  (format #t "~a" val))
+(define-maybe raw-content)
+
 (define-configuration mod-muc-configuration
   (name
    (string "Prosody Chatrooms")
@@ -533,7 +539,12 @@ See also @url{http://prosody.im/doc/modules/mod_muc}."
     (hostname
      (string (configuration-missing-field 'ext-component 'hostname))
      "Hostname of the component."
-     ext-component)))
+     ext-component)
+
+    (raw-content
+     (maybe-raw-content 'disabled)
+     "Raw content that will be added to the configuration file."
+     common)))
 
 ;; Serialize Virtualhost line first.
 (define (serialize-virtualhost-configuration config)