System: add basic system mgmt entries like host-/domainname

docs/ch12-system.rst

@@ -1,6 +1,183 @@
 System
 ======
 
+After a basic system setup by setting up `Interface Addresses`_, VyOS should
+be ready for further configuration which is described in this chapter.
+
+Host Information
+----------------
+
+This section describes the system's host information and how to configure them,
+it covers the following topics:
+
+* Host name
+* Domain
+* IP address
+* Default gateway
+* Aliases
+
+Host Name
+^^^^^^^^^
+
+A hostname is the label (name) assigned to a network device (a host) on a
+network and is used to distinguish one device from another on specific networks
+or over the internet.
+
+Set a system host name:
+
+.. code-block:: sh
+
+  set system host-name <hostname>
+
+**NOTE:** Only letters, numbers and hyphens are allowed.
+
+Show host name:
+
+.. code-block:: sh
+
+  show system host-name
+
+Delete host name:
+
+.. code-block:: sh
+
+  delete system host-name <hostname>
+
+Example: Set system hostname to 'RT01':
+
+.. code-block:: sh
+
+  set system host-name RT01
+  commit
+  show system host-name
+    host-name RT01
+
+Domain Name
+^^^^^^^^^^^
+
+A domainname is the label (name) assigned to a computer network and is thus
+unique!
+
+Set the system's domain:
+
+.. code-block:: sh
+
+  set system domain-name <domain>
+
+**NOTE:** Only letters, numbers, hyphens and periods are allowed.
+
+Show domain:
+
+.. code-block:: sh
+
+  show system domain-name
+
+Remove domain name:
+
+.. code-block:: sh
+
+  set system delete domain-name <domain>
+
+Example: Set system domain to example.com:
+
+.. code-block:: sh
+
+  set system domain-name example.com
+  commit
+  show system domain-name
+    domain-name example.com
+
+Static host mappings
+^^^^^^^^^^^^^^^^^^^^
+
+How to assign IPs to interfaces is described in chapter `Interface Addresses`_.
+This section shows how to statically map a system IP to its host name for
+local (meaning on this VyOS instance) DNS resolution:
+
+.. code-block:: sh
+
+  set system static-host-mapping host-name <hostname> inet <IP address>
+
+Show static mapping:
+
+.. code-block:: sh
+
+  show system static-host-mapping
+
+Example: Create a static mapping between the system's hostname `RT01` and
+IP address `10.20.30.41`:
+
+.. code-block:: sh
+
+  set system static-host-mapping host-name RT01 inet 10.20.30.41
+  commit
+  show system static-host-mapping
+    host-name RT01 {
+        inet 10.20.30.41
+    }
+
+Aliases
+*******
+
+One or more system aliases (static mappings) can be defined:
+
+.. code-block:: sh
+
+  set system static-host-mapping host-name <hostname> alias <alias>
+
+Show aliases:
+
+.. code-block:: sh
+
+  show system static-mapping
+
+Delete alias:
+
+.. code-block:: sh
+
+  delete system static-host-mapping host-name <hostname> alias <alias>
+
+Example: Set alias `router1` for system with hostname `RT01`:
+
+.. code-block:: sh
+
+  set system static-host-mapping host-name RT01 alias router1
+  commit
+  show system static-host-mapping
+    host-name RT01 {
+        alias router1
+        inet 10.20.30.41
+    }
+
+Default Gateway/Route
+^^^^^^^^^^^^^^^^^^^^^
+
+In the past (VyOS 1.1.8) used a gateway-address configured in the system tree
+(`set system gateway-address <IP address>`) this is no longer supported and
+existing configurations are migrated to the new CLI commands.
+
+It is replaced by inserting a static route into the routing table using:
+
+.. code-block:: sh
+
+  set protocols static route 0.0.0.0/0 next-hop <gateway ip>
+
+Delete default route fomr the system
+
+.. code-block:: sh
+
+  delete protocols static route 0.0.0.0/0
+
+Show default route:
+
+.. code-block:: sh
+
+  vyos@vyos$ show ip route 0.0.0.0
+  Routing entry for 0.0.0.0/0
+    Known via "static", distance 1, metric 0, best
+    Last update 3d00h23m ago
+    * 172.16.34.6, via eth1
+
 System Users
 ------------