[3880] Minimalistic description in the User's Guide added

doc/guide/Makefile.am

@@ -7,7 +7,7 @@ dist_html_DATA = $(HTMLDOCS) kea-guide.css
 
 DOCBOOK = kea-guide.xml intro.xml quickstart.xml install.xml admin.xml config.xml
 DOCBOOK += keactrl.xml dhcp4-srv.xml dhcp6-srv.xml logging.xml ddns.xml hooks.xml
-DOCBOOK += libdhcp.xml lfc.xml stats.xml
+DOCBOOK += libdhcp.xml lfc.xml stats.xml ctrl-channel.xml
 
 EXTRA_DIST = $(DOCBOOK)
 DISTCLEANFILES = $(HTMLDOCS) $(DOCS) kea-messages.xml

doc/guide/ctrl-channel.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+<!ENTITY mdash  "&#x2014;" >
+<!ENTITY % version SYSTEM "version.ent">
+%version;
+]>
+
+  <chapter id="ctrl-channel">
+    <title>Management API</title>
+    <para>
+      @todo: To be implemented in ticket 3880.
+    </para>
+
+  </chapter>

doc/guide/dhcp4-srv.xml

@@ -2793,6 +2793,36 @@ temporarily override a list of interface names and listen on all interfaces.
         </table>
     </section>
 
+    <section id="dhcp4-ctrl-channel">
+      <title>Management API for the DHCPv4 server</title>
+      <para>
+        Management API has been introduced in Kea 0.9.2. It allows issuing specific
+        management commands, like statistics retrieval, reconfiguration or shutdown.
+        For more details, see <xref linkend="ctrl-channel" />. Currently the only
+        supported communication channel type is UNIX stream socket. By default there
+        are no sockets open. To instruct Kea to open a socket, the following entry
+        in the configuration file can be used:
+<screen>
+"Dhcp4": {
+    "control-socket": {
+        "socket-type": "unix",
+        "socket-name": <userinput>"/path/to/the/unix/socket"</userinput>
+    },
+
+    "subnet4": [
+        ...
+    ],
+    ...
+}
+</screen>
+      </para>
+
+      <para>
+        Communication over control channel is conducted using JSON structures.
+        See the Control Channel section in the Kea Developer's Guide for more details.
+      </para>
+    </section>
+
     <section id="dhcp4-std">
       <title>Supported DHCP Standards</title>
       <para>The following standards are currently supported:</para>

doc/guide/kea-guide.xml

@@ -75,6 +75,8 @@
 
   <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="stats.xml" />
 
+  <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="ctrl-channel.xml" />
+
   <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="libdhcp.xml" />
 
   <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="logging.xml" />