Add support for symlink'd interfaces file

Also minor changes to avoid crash on empty file or syntax error

1 files changed, 17 insertions, 3 deletions

diff --git a/interfaces-model.lua b/interfaces-model.lua
index 2d9ff6d..156e1b5 100644
--- a/interfaces-model.lua
+++ b/interfaces-model.lua
@@ -7,7 +7,7 @@ fs = require("acf.fs")
 format = require("acf.format")
 
 local servicename = "networking"
-local filename = "/etc/network/interfaces"
+local interfacesfile = "/etc/network/interfaces"
 
 local array
 
@@ -15,6 +15,20 @@ local array
 -- Depending on the address family and corresponding method, different options are valid
 local iface = require("alpine-baselayout/interfaces-definitions")
 
+local followlink = function(path)
+	local where = path
+	while fs.is_link(where) do
+		local link = posix.readlink(where)
+		if link and not string.find(link, "^/") then
+			link = posix.dirname(where).."/"..link
+		end
+		where = link
+	end
+	return where
+end
+
+local filename = followlink(interfacesfile)
+
 -- Create an interface structure with all options
 local get_blank_iface = function ()
 	local f =  {}
@@ -86,7 +100,7 @@ end
 -- This function parses the interfaces file and creates array
 local unpack_interfaces = function ()
 	if array == nil then
-		local filecontent = fs.read_file(filename)
+		local filecontent = fs.read_file(filename) or ""
 		-- make sure it has a terminating \n
 		filecontent  = string.gsub (filecontent, "([^\n])$", "%1\n")
 
@@ -110,7 +124,7 @@ local unpack_interfaces = function ()
 				interface.name.value = name or ""
 				interface.family.value = family or ""
 				interface.method.value = method or ""
-			elseif #array then
+			elseif #array > 0 then
 				-- it must be some kind of parameter
 				local param, val =
 					string.match(line, "(%S+)%s*(.*)$")