services: Add a service for opendht.

* gnu/services/networking.scm (maybe-number?, maybe-string?): New procedures.
(<opendht-configuration>): New configuration record.
(%opendht-accounts): New variable.
(opendht-configuration->command-line-arguments): New procedure.
(opendht-shepherd-service, opendht-service-type): New variables.
* doc/guix.texi (Networking Services): Document the new service.

1 files changed, 93 insertions, 0 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index a10943f2d5..a8ee27cae7 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -16688,6 +16688,99 @@ must be @code{'()} or @code{'("internal")}.
 detailed discussion of each configuration field.
 @end deftp
 
+@cindex opendht, distributed hash table network service
+@cindex dhtproxy, for use with jami
+@defvr {Scheme Variable} opendht-service-type
+This is the type of the service running a @uref{https://opendht.net,
+OpenDHT} node, @command{dhtnode}.  The daemon can be used to host your
+own proxy service to the distributed hash table (DHT), for example to
+connect to with Jami, among other applications.
+
+@quotation Important
+When using the OpenDHT proxy server, the IP addresses it ``sees'' from
+the clients should be addresses reachable from other peers.  In practice
+this means that a publicly reachable address is best suited for a proxy
+server, outside of your private network.  For example, hosting the proxy
+server on a IPv4 private local network and exposing it via port
+forwarding could work for external peers, but peers local to the proxy
+would have their private addresses shared with the external peers,
+leading to connectivity problems.
+@end quotation
+
+The value of this service is a @code{opendht-configuration} object, as
+described below.
+@end defvr
+
+@deftp {Data Type} opendht-configuration
+This is the data type for the OpenDHT service configuration.
+
+@c The fields documentation has been auto-generated using the
+@c configuration->documentation procedure from
+@c (gnu services configuration).
+Available @code{opendht-configuration} fields are:
+
+@deftypevr {@code{opendht-configuration} parameter} package opendht
+The @code{opendht} package to use.
+
+@end deftypevr
+
+@deftypevr {@code{opendht-configuration} parameter} boolean peer-discovery?
+Whether to enable the multicast local peer discovery mechanism.
+
+Defaults to @samp{#f}.
+
+@end deftypevr
+
+@deftypevr {@code{opendht-configuration} parameter} boolean enable-logging?
+Whether to enable logging messages to syslog.  It is disabled by default
+as it is rather verbose.
+
+Defaults to @samp{#f}.
+
+@end deftypevr
+
+@deftypevr {@code{opendht-configuration} parameter} boolean debug?
+Whether to enable debug-level logging messages.  This has no effect if
+logging is disabled.
+
+Defaults to @samp{#f}.
+
+@end deftypevr
+
+@deftypevr {@code{opendht-configuration} parameter} maybe-string bootstrap-host
+The node host name that is used to make the first connection to the
+network.  A specific port value can be provided by appending the
+@code{:PORT} suffix.  By default, it uses the Jami bootstrap nodes, but
+any host can be specified here.  It's also possible to disable
+bootsrapping by setting this to the @code{'disabled} symbol.
+
+Defaults to @samp{"bootstrap.jami.net:4222"}.
+
+@end deftypevr
+
+@deftypevr {@code{opendht-configuration} parameter} maybe-number port
+The UDP port to bind to.  When set to @code{'disabled}, an available
+port is automatically selected.
+
+Defaults to @samp{4222}.
+
+@end deftypevr
+
+@deftypevr {@code{opendht-configuration} parameter} maybe-number proxy-server-port
+Spawn a proxy server listening on the specified port.
+
+Defaults to @samp{disabled}.
+
+@end deftypevr
+
+@deftypevr {@code{opendht-configuration} parameter} maybe-number proxy-server-port-tls
+Spawn a proxy server listening to TLS connections on the specified port.
+
+Defaults to @samp{disabled}.
+
+@end deftypevr
+@end deftp
+
 @cindex Tor
 @defvr {Scheme Variable} tor-service-type
 This is the type for a service that runs the @uref{https://torproject.org,