pretty-hostname: add package to manage a "pretty" hostname

admin/pretty-hostname/Makefile

@@ -0,0 +1,35 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=pretty-hostname
+PKG_VERSION:=1
+
+PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/pretty-hostname
+  SECTION:=admin
+  CATEGORY:=Administration
+  DEPENDS:=+uci
+  TITLE:=Manage a "pretty" hostname in addition to the actual one
+endef
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)
+endef
+
+define Build/Configure
+endef
+
+define Build/Compile
+endef
+
+define Package/pretty-hostname/install
+	$(INSTALL_DIR) $(1)/bin
+	$(INSTALL_BIN) ./files/pretty-hostname $(1)/bin/
+
+	$(INSTALL_DIR) $(1)/usr/lib/lua
+	$(INSTALL_DATA) ./files/pretty_hostname.lua $(1)/usr/lib/lua/
+endef
+
+$(eval $(call BuildPackage,pretty-hostname))

admin/pretty-hostname/files/pretty-hostname

@@ -0,0 +1,34 @@
+#!/bin/sh
+
+set -e
+
+case $# in
+0)
+	uci -q get 'system.@system[0].pretty_hostname' || uci get 'system.@system[0].hostname'
+	;;
+1)
+	local pretty_hostname="$1"
+	# Remove invalid characters and leading/trailing spaces
+	local hostname="$(echo -n "$pretty_hostname" | sed -r -e 's/[^a-zA-Z0-9-]//g' -e 's/-+/-/g' -e 's/^-//')"
+	hostname="${hostname:0:63}"
+	hostname="$(echo -n "$hostname" | sed -e 's/-$//')"
+
+	if [ -z "$hostname" ]; then
+		hostname='localhost'
+	fi
+
+	if [ "$hostname" = "$pretty_hostname" ]; then
+		uci -q delete "system.@system[0].pretty_hostname"
+	else
+		uci set "system.@system[0].pretty_hostname=$pretty_hostname"
+	fi
+
+	uci set "system.@system[0].hostname=$hostname"
+	uci commit system
+
+	echo "$hostname" > /proc/sys/kernel/hostname
+	;;
+*)
+	echo 'Usage: pretty-hostname [ hostname ]'
+	exit 1
+esac

admin/pretty-hostname/files/pretty_hostname.lua

@@ -0,0 +1,43 @@
+local assert = assert
+local string = string
+
+module 'pretty_hostname'
+
+local function get_system(uci)
+	local system
+	uci:foreach('system', 'system',
+		function(s)
+			system = s
+			return false
+		end
+	)
+	return assert(system, 'unable to find system section')
+end
+
+function get(uci)
+	local system = get_system(uci)
+
+	return system.pretty_hostname or system.hostname
+end
+
+function set(uci, pretty_hostname)
+	local system = get_system(uci)['.name']
+
+	local hostname = string.gsub(pretty_hostname, '[^a-zA-Z0-9%-]', '')
+	hostname = string.gsub(hostname, '%-+', '-')
+	hostname = string.gsub(hostname, '^%-', '')
+	hostname = string.sub(hostname, 1, 63)
+	hostname = string.gsub(hostname, '%-$', '')
+
+	if hostname == '' then
+		hostname = 'localhost'
+	end
+
+	if hostname == pretty_hostname then
+		uci:delete('system', system, 'pretty_hostname')
+	else
+		uci:set('system', system, 'pretty_hostname', pretty_hostname)
+	end
+
+	uci:set('system', system, 'hostname', hostname)
+end