T145: Migrate vyos history, migrate vyatta, ipsec-gre and restructure of configuration overview (#69)

* T1457: restructure configuration overview for the beginner user

* T1457: install: restructure note about deprecated install system

* T1457: migrate vyos history from the wiki

* T1457: Migrate from vyatta: Migrated from the wiki

* T1457: VPN: Migrate gre-ipsec from the wiki

1 files changed, 129 insertions, 17 deletions

diff --git a/docs/configuration-overview.rst b/docs/configuration-overview.rst
index 3024c277..f7a3b078 100644
--- a/docs/configuration-overview.rst
+++ b/docs/configuration-overview.rst
@@ -63,9 +63,12 @@ The current configuration can be viewed using the show configuration command.
   }
   vyos@vyos:~$
 
-Because configuration changes are made using `set` and `delete` commands, the
-commands to generate the active configuration can also be displayed using the
-`show configuration commands` command.
+By default the configuration is display'ed in a hierarchy like the example above, 
+this is only one of the possible ways to display the configuration.
+
+When the configuration is generated and the device is configured, these changes are added 
+with a corresponding set of `set` and `delete` commands, as for this you could also display
+the current configuration using these `set` commands using the `show configuration commands` command.
 
 .. code-block:: sh
 
@@ -85,28 +88,39 @@ commands to generate the active configuration can also be displayed using the
   set system syslog global facility protocols level 'debug'
   vyos@vyos:~$
 
-Configuration changes made do not take effect until committed using the commit
-command in configuration mode.
+Both these commands are for beeing executed when in operational mode, these commands does not work within the configuration mode.
+
+Navigating in Configuration Mode 
+---------------------------------
+When entering the configuration mode you are navigating inside the tree structure exported in the overview above,
+to enter configuration mode enter the command `configure` when in operational mode
 
 .. code-block:: sh
 
-  vyos@vyos# commit
+  vyos@vyos$ configure
   [edit]
-  vyos@vyos# exit
-  Warning: configuration changes have not been saved.
-  vyos@vyos:~$
+  cyos@vyos# 
 
-In order to preserve configuration changes upon reboot, the configuration must
-also be saved once applied. This is done using the save command in
-configuration mode.
+.. note:: Prompt changes from `$` to `#`. To exit configuration mode, type `exit`.
 
-.. code-block:: sh
+All commands executed here is relative to the configuration level you have entered, everything is possible to do from the top level
+but commands will be quite lengthy when manually typing them.
 
-  vyos@vyos# save
-  Saving configuration to '/config/config.boot'...
-  Done
+To change the current hierarchy level use the command: `edit`
+
+.. code-block:: sh
+  
   [edit]
-  vyos@vyos#
+  vyos@vyos# edit interfaces ethernet eth0 
+
+  [edit interfaces ethernet eth0]
+  vyos@vyos# 
+
+You are now in a sublevel relative to `interfaces ethernet eth0`, 
+all commands executed from this point on are relative to this sublevel.
+to exit back to the top of the hierarchy use the `top` command or the `exit` command.
+This brings you back to the top of the hierarchy.
+
 
 The show command within configuration mode will show the current configuration
 indicating line changes with a + for additions and a - for deletions.
@@ -136,6 +150,87 @@ indicating line changes with a + for additions and a - for deletions.
   [edit]
   vyos@vyos#
 
+it is also possible to display all `set` commands within configuration mode using `show | commands`
+
+.. code-block:: sh
+
+  vyos@vyos# show interfaces iethernet eth0 | commands
+  set address dhcp
+  set hw-id 00:0c:29:44:3b:0f
+
+these command is also relative to the level you are inside and only relevant configuration blocks will be displayed when entering a sub-level
+
+.. code-block:: sh
+
+  [edit interfaces ethernet eth0]
+  vyos@vyos# show
+   address dhcp
+   hw-id 00:0c:29:44:3b:0f
+
+exiting from the configuration mode is done via the `exit` command from the top level, executing `exit` from within a sub-level takes you back to the top level.
+
+.. code-block:: sh
+
+  [edit interfaces ethernet eth0]
+  vyos@vyos# exit
+  [edit]
+  vyos@vyos# exit
+  Warning: configuration changes have not been saved.
+  vyos@vyos:~$
+
+
+
+
+Managing the configuration
+--------------------------
+
+The configuration is managed by the use of `set` and `delete` commands from within configuration mode
+Configuration commands are flattend from the tree into 'one-liner' commands shown in `show configuration commands` from operation mode
+
+these commands are also relative to the level where they are executed and all redundant information from the current level is removed from the command entered
+
+.. code-block:: sh
+
+  [edit]
+  vyos@vyos# set interface ethernet eth0 address 1.2.3.4/24
+
+  [edit interfaces ethernet eth0]
+  vyos@vyos# set address 1.2.3.4/24
+
+These two commands are essential the same, just executed from different levels in the hierarchy  
+
+To delete a configuration entry use the `delete` command, this also deletes all sub-levels under the current level you've specified in the `delete` command.
+Deleting a entry could also mean to reset it back to its default value if the element is mandatory, in each case it will be removed from the configuration file
+
+.. code-block:: sh
+
+  [edit interfaces ethernet eth0]
+  vyos@vyos#  delete address 1.2.3.4/24
+
+Configuration changes made do not take effect until committed using the commit
+command in configuration mode.
+
+.. code-block:: sh
+
+  vyos@vyos# commit
+  [edit]
+  vyos@vyos# exit
+  Warning: configuration changes have not been saved.
+  vyos@vyos:~$
+
+In order to preserve configuration changes upon reboot, the configuration must
+also be saved once applied. This is done using the save command in
+configuration mode.
+
+.. code-block:: sh
+
+  vyos@vyos# save
+  Saving configuration to '/config/config.boot'...
+  Done
+  [edit]
+  vyos@vyos#
+
+ 
 Configuration mode can not be exited while uncommitted changes exist. To exit
 configuration mode without applying changes, the exit discard command can be
 used.
@@ -209,3 +304,20 @@ or TFTP.
   Saving configuration to 'tftp://192.168.0.100/vyos-test.config.boot'...
   ######################################################################## 100.0%
   Done
+
+Operational info from config mode
+---------------------------------
+
+When inside configuration mode you are not directly able to execute operational commands,
+access to these commands are possible trough the use of the `run [command]` command.
+from this command you will have access to everything accessable from operational mode,
+Command completeion and syntax help with `?` and `[tab]` wil also work.
+
+.. code-block:: sh
+  
+  [edit]
+  vyos@vyos# run show interfaces
+  Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
+  Interface        IP Address                        S/L  Description
+  ---------        ----------                        ---  -----------
+  eth0             0.0.0.0/0                         u/u