feat: Add support for meshchat_local.lua (#47)

Package upgrades do not update the `meshchatconfig.lua` because
it is tagged as a configuration file. This prevents settings
from being lost, but makes it difficult to add new settings
in future releases. This change establishes the `meshchat_local.lua`
file for local administrators to configure there MeshChat.

During installation of a package if a `meshchat_local.lua` is not
found, then a copy of `meshchatconfig.lua` is copied and
sanitized of the `app_version` and `protocol_version` settings.

Signed-off-by: Gerard Hickey <hickey@kinetic-compute.com>

README.md

@@ -13,4 +13,6 @@ If you are looking for a feature to be implemented or find a bug, please
 be sure to [create an issue](https://github.com/hickey/meshchat/issues/new)
 in the project so that it can be prioritized.
 
+Current documentation for MeshChat can be found at:
 
+    https://hickey.github.io/meshchat

docs/Install.md

@@ -10,8 +10,31 @@ system will be started within a couple of seconds.
 
 Usually there is not really any configuration that needs to be done, but
 review of the [configuration settings](../module/meshchatconfig.html) is
-suggested. To make any configuration changes one needs to log into the
-node using SSH and edit the file `/www/cgi-bin/meshchatconfig.lua`.
+suggested.
+
+Starting with `v2.12.0` the configuration of MeshChat occurs in the file
+`/www/cgi-bin/meshchat_local.lua`. Any configuration settings that need
+to be modified need to be entered into the `meshchat_local.lua` file and
+not in the `meshchatconfig.lua` file that previous version used to
+configure MeshChat. Making changes to `meshchatconfig.lua` will be lost
+when MeshChat is upgraded or downgraded. Making changes to the configuration
+still requires one to SSH into the node and edit `meshchat_local.lua`
+directly.
+
+## Setting the MeshChat Zone Name
+
+MeshChat uses a zone name to locate other MeshChat servers running with
+the same zone name. Once servers are added to the same zone name, they
+will automatically synchronize their message databases with one another.
+Setting the zone name is done in the AREDN node adminstration settings
+under the advertised services.
+
+After a new install of MeshChat the installation will randomly generate
+a zone name and register it with the AREDN node. The service name
+(i.e. zone name) can be changed to the desired zone name used by other
+MeshChat servers. Once the service name has been saved, it is best to
+reboot the AREDN node to insure that MeshChat is restarted with the
+correct zone name.
 
 ## Installing MeshChat on Linux
 

meshchatconfig.lua

@@ -1,4 +1,14 @@
 --[[
+	STOP STOP STOP DO NOT EDIT THIS FILE
+
+	This file is used to set default values for MeshChat and should NOT
+	be edited. Edits made to this file WILL BE LOST when upgrading or
+	downgrading MeshChat. All the values below can be overridden by
+	adding them to the meshchat_local.lua file located in the same
+	directory as this file.
+
+	EDIT THIS FILE AT YOUR PERIL. YOU HAVE BEEN WARNED.
+
 
 	Part of AREDN -- Used for creating Amateur Radio Emergency Data Networks
 	Copyright (C) 2022 Tim Wilkinson
@@ -77,3 +87,5 @@ extra_nodes                = {}
 protocol_version           = "1.02"
 app_version                = "master"
 default_channel            = ""
+
+require("meshchat_local")

package/meshchat/preinst

@@ -4,4 +4,16 @@
 
 mkdir -p /www/meshchat
 
+# if there is not a meshchat_local.lua, then prepare one
+if [ ! -f /www/cgi-bin/meshchat_local.lua ]; then
+    if [ -f /www/cgi-bin/meshchatconfig.lua ]; then
+        cp /www/cgi-bin/meshchatconfig.lua /www/cgi-bin/meshchat_local.lua
+
+        # remove vars that should not be in meshchat_local.lua
+        sed -i "/^protocol_version/d; /^app_version/d" /www/cgi-bin/meshchat_local.lua
+    else
+        touch /www/cgi-bin/meshchat_local.lua
+    fi
+fi
+
 exit 0