* fix(cache): web UI can read what the display service caches again ledmatrix-web.service carried CacheDirectory=ledmatrix. With User= set to the installing user, systemd re-owns /var/cache/ledmatrix and everything in it to that user and its primary group whenever the directory's owner differs -- for a directory root created, on the first start. That erased the root:ledmatrix setgid layout the installers set up, so every file the display service (root) wrote afterwards was root:root 0660 and unreadable by the web interface: WARNING - Permission denied loading cache for display_current_state ... Since #547 install_service.sh renders the web unit from the template, so every fresh install hit this. Measured on one rig: 392 unreadable files, and the web UI's display status, on-demand state and plugin health empty. Existing installs only receive `git pull`, never a reinstalled unit, so the fix for them is in the code the root display service runs: - DiskCache.set gives each file the directory's group (when the directory is group-writable) and 0660 on the open descriptor before the rename, independent of setgid. This also closes a window where a fresh file was visible as mkstemp's 0600. - DiskCache.share_existing_files repairs files an older version left behind, once per process from the cleanup thread. It works through O_NOFOLLOW descriptors and skips hard links and other users' files: the directory is writable by the web user, and root must not be steered into changing a file outside it. For new installs, the web unit drops CacheDirectory=/CacheDirectoryMode=, and install_web_service.sh stops replacing an existing directory's ledmatrix group with the user's group. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(web): on-demand and current-display status read the display's latest state Found testing the cache-permission fix on a rig: once the web interface could read display_on_demand_state at all, /display/on-demand/status kept answering "active" for over 100 seconds while the file on disk said "idle". Both status routes read the display service's keys through the web process's memory tier, which serves the first copy it read for the full max_age (120s). Read them with memory_ttl=0, as every other cross-process reader (plugin health/metrics, the on-demand mailbox) already does. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(install): re-group the cache dir whenever the web user is outside its group install_web_service.sh replaced an existing cache directory's group only when it was root's. A directory in any other group the web user is not a member of -- root:ledmatrix, for a user who is not in ledmatrix -- was left alone, and every file root wrote there stayed unreadable to the web interface. Replace the group whenever the installing user is not in it. A directory whose group the user is already in (ledmatrix, or the user's own group where CacheDirectory= left it) is still left as it is: re-grouping a working directory strands the files already in it on the old group. When the group does change and root-owned JSON files carrying the old group are present, try-restart ledmatrix.service so DiskCache.share_existing_files re-groups them through its symlink- and hard-link-safe path, rather than a recursive chgrp. Verified under WSL's systemd for seven directory states (user group, ledmatrix member, ledmatrix non-member with and without root files, root:root, missing, unnamed gid); the previous version left the non-member case unchanged. Addresses CodeRabbit review on #593. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
LED Matrix Web Interface V3
Modern, production web interface for controlling the LED Matrix display.
Overview
This directory contains the active V3 web interface with the following features:
- Real-time display preview via Server-Sent Events (SSE)
- Plugin management and configuration
- System monitoring and logs
- Modern, responsive UI
- RESTful API
Directory Structure
web_interface/
├── app.py # Main Flask application
├── start.py # Startup script
├── run.sh # Shell runner script
├── requirements.txt # Python dependencies
├── blueprints/ # Flask blueprints
│ ├── api_v3.py # API endpoints
│ └── pages_v3.py # Page routes
├── templates/ # HTML templates
│ └── v3/
│ ├── base.html
│ ├── index.html
│ └── partials/
└── static/ # CSS/JS assets
└── v3/
├── app.css
├── app.js
├── manifest.json # PWA manifest
├── plugins_manager.js
├── icons/ # PWA / touch icons
├── js/ # Alpine, htmx, app shell, widgets, utils
└── vendor/ # codemirror, fontawesome
Running the Web Interface
Standalone (Development)
From the project root:
python3 web_interface/start.py
Or using the shell script:
./web_interface/run.sh
As a Service (Production)
The web interface can run as a systemd service that starts automatically based on the web_display_autostart configuration setting:
sudo systemctl start ledmatrix-web
sudo systemctl enable ledmatrix-web # Start on boot
Accessing the Interface
Once running, access the web interface at:
- Local: http://localhost:5000
- Network: http://:5000
Configuration
The web interface reads configuration from:
config/config.json- Main configurationconfig/config_secrets.json- API keys and secrets
API Documentation
The V3 API is mounted at /api/v3/ (app.py:144). For the complete
list and request/response formats, see
docs/REST_API_REFERENCE.md. Quick
reference for the most common endpoints:
Configuration
GET /api/v3/config/main- Get main configurationPOST /api/v3/config/main- Save main configurationGET /api/v3/config/secrets- Get secrets configurationPOST /api/v3/config/raw/main- Save raw main config (Config Editor)POST /api/v3/config/raw/secrets- Save raw secrets
Display & System Control
GET /api/v3/system/status- System statusPOST /api/v3/system/action- Control display (action body:start_display,stop_display,restart_display_service,restart_web_service,git_pull,reboot_system,shutdown_system,enable_autostart,disable_autostart)GET /api/v3/display/current- Current display frameGET /api/v3/display/on-demand/status- On-demand statusPOST /api/v3/display/on-demand/start- Trigger on-demand displayPOST /api/v3/display/on-demand/stop- Clear on-demand
Plugins
GET /api/v3/plugins/installed- List installed pluginsGET /api/v3/plugins/config?plugin_id=<id>- Get plugin configPOST /api/v3/plugins/config- Update plugin configurationGET /api/v3/plugins/schema?plugin_id=<id>- Get plugin schemaPOST /api/v3/plugins/toggle- Enable/disable pluginPOST /api/v3/plugins/install- Install from registryPOST /api/v3/plugins/install-from-url- Install from GitHub URLPOST /api/v3/plugins/uninstall- Uninstall pluginPOST /api/v3/plugins/update- Update plugin
Plugin Store
GET /api/v3/plugins/store/list- List available registry pluginsGET /api/v3/plugins/store/github-status- GitHub authentication statusPOST /api/v3/plugins/store/refresh- Refresh registry from GitHub
Real-time Streams (SSE)
SSE stream endpoints are defined directly on the Flask app
(app.py:607-619 — includes the CSRF exemption and rate-limit hookup
alongside the three route definitions), not on the api_v3 blueprint:
GET /api/v3/stream/stats- System statistics streamGET /api/v3/stream/display- Display preview streamGET /api/v3/stream/logs- Service logs stream
Development
When making changes to the web interface:
- Edit files in this directory
- Test changes by running
python3 web_interface/start.py - Restart the service if running:
sudo systemctl restart ledmatrix-web
Notes
- Templates and static files use the
v3/prefix to allow for future versions - The interface uses Flask blueprints for modular organization
- SSE streams provide real-time updates without polling