1. What is LuCI
LuCI is the Web UI framework for OpenWrt, with core features:
-
Based on Lua + uhttpd + ubus/uci
-
Configuration-driven (does not directly modify files, but modifies UCI)
-
Light coupling, plugin support (package)
2. Overall Architecture Diagram
3. Core Components
|
Layer |
Role |
Common Content |
|
uhttpd |
HTTP Entry |
/etc/config/uhttpd |
|
Lua/dispatcher |
URL Router → Controller |
/usr/lib/lua/luci/dispatcher.lua |
|
Controller |
Handles requests & calls UCI/ubus |
/usr/lib/lua/luci/controller/… |
|
Model |
Read/Write UCI / RPCD |
/usr/lib/lua/luci/model/… |
|
View |
Render HTML |
/usr/lib/lua/luci/view/… |
|
UCI |
Persistent configuration data |
/etc/config/… |
|
ubus/rpcd |
API layer interacting with the system |
wifi, firewall, system |
4. Request Handling Process (Example: “Save Wi-Fi Configuration”)
(1) Browser clicks “Save” → POST
(2) uhttpd forwards to LuCI dispatcher
(3) Dispatcher finds the corresponding Controller
(4) Controller calls Model to write UCI: wifi.ssid=”MyAP”
(5) Submit UCI → uci commit wireless
(6) Controller triggers system action (ubus call hostapd reload)
(7) Returns JSON / HTML page
Features: All configurations do not directly modify files, but go through UCI + commit
5. Configuration Persistence Mechanism
- Edit = uci set
- Save & Apply = uci commit + reload/restart
- Modifies the /etc/config/* files (unified entry, convenient for scripts/CLI/GUI to share)
6. Plugin Extension Mechanism (How to Add a Page)
Adding new functionality generally requires three things:
/usr/lib/lua/luci/controller/myapp.lua ← Routing + Control Logic
/usr/lib/lua/luci/model/cbi/myapp/.lua ← Model file for calling UCI
/usr/lib/lua/luci/view/myapp/.htm ← Page template
After registering the route, restart uhttpd/LuCI to display the UI module.
7. Why LuCI is Suitable for Routers/Embedded Systems
- Runs on low RAM/Flash (Lua is lightweight)
- Unified system configuration model (UCI)
- RPC-oriented (can seamlessly collaborate with CLI/scripts/daemon)
- Plugin structure adapts to ODM/OEM scenarios