Release v1.1.2: publish container image + add security workflows

- Bump VERSION to 1.1.2 (no app behavior change from 1.1.1).
- release.yml: add workflow_dispatch so images can be published manually from
  the Actions tab in addition to on version tags.
- Add CodeQL code scanning (Python + JavaScript), free for public repos.
- Add Dependabot config for GitHub Actions and pip updates.

This is the first release to publish a multi-arch image to GHCR
(ghcr.io/allennpit/ads-bit).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.dockerignore

@@ -3,6 +3,7 @@ __pycache__
 *.pyc
 *.pyo
 config.json
+data/
 screenshots/
 .claude/
 CLAUDE.md

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,29 @@
+---
+name: Bug report
+about: Report something that isn't working
+title: "[Bug] "
+labels: bug
+---
+
+**Describe the bug**
+A clear description of what's wrong.
+
+**To reproduce**
+Steps to reproduce the behavior:
+1. …
+2. …
+
+**Expected behavior**
+What you expected to happen.
+
+**Screenshots / logs**
+If applicable, add screenshots or server log output.
+
+**Environment**
+- ADS-Bit version (admin header or `GET /api/config`):
+- Install method: [ ] bare metal  [ ] Docker  [ ] Podman
+- OS / Python version:
+- Receiver / feed (e.g. dump1090, readsb) and how it's reached:
+
+**Additional context**
+Anything else that might help.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,18 @@
+---
+name: Feature request
+about: Suggest an idea or improvement
+title: "[Feature] "
+labels: enhancement
+---
+
+**What problem does this solve?**
+A clear description of the need or pain point.
+
+**Proposed solution**
+What you'd like to happen.
+
+**Alternatives considered**
+Any other approaches you thought about.
+
+**Additional context**
+Mockups, examples, or references.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,19 @@
+## Summary
+
+<!-- What does this PR change, and why? -->
+
+## Related issues
+
+<!-- e.g. Closes #123 -->
+
+## How was this tested?
+
+<!-- Commands run, manual steps, screenshots. For Docker changes, note that
+     `docker build` succeeds. -->
+
+## Checklist
+
+- [ ] Server starts and the change works locally (`python3 server.py`)
+- [ ] If admin assets changed, bumped the `?v=` cache-bust token in `admin/admin.html`
+- [ ] If behavior/version changed, updated `VERSION` and `CHANGELOG.md`
+- [ ] No secrets or local config committed (`config.json` stays ignored)

.github/dependabot.yml

@@ -0,0 +1,17 @@
+version: 2
+updates:
+  # Keep GitHub Actions pinned versions current.
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: weekly
+    commit-message:
+      prefix: "ci"
+
+  # Keep Python dependencies current.
+  - package-ecosystem: pip
+    directory: "/"
+    schedule:
+      interval: weekly
+    commit-message:
+      prefix: "deps"

.github/workflows/ci.yml

@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  python:
+    name: Python checks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+      - name: Byte-compile server
+        run: python -m compileall -q server.py
+      - name: Validate example config is valid JSON
+        run: python -c "import json; json.load(open('config.json.example'))"
+
+  docker:
+    name: Docker build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build image
+        run: docker build -t ads-bit:ci .

.github/workflows/codeql.yml

@@ -0,0 +1,35 @@
+name: CodeQL
+
+# Static security analysis (free for public repositories). Scans the Python
+# backend and the vanilla-JS frontend on pushes, PRs, and weekly.
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  schedule:
+    - cron: "23 5 * * 1"
+
+jobs:
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      contents: read
+      actions: read
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [python, javascript]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v3
+        with:
+          languages: ${{ matrix.language }}
+      - name: Analyze
+        uses: github/codeql-action/analyze@v3
+        with:
+          category: "/language:${{ matrix.language }}"

.github/workflows/release.yml

@@ -0,0 +1,59 @@
+name: Release
+
+# Build and publish a multi-arch image to GitHub Container Registry (GHCR)
+# whenever a version tag is pushed (e.g. v1.1.2). Lets users run a prebuilt
+# image — including on Raspberry Pi (arm64) — without building locally.
+
+on:
+  push:
+    tags: ["v*"]
+  workflow_dispatch:
+    inputs:
+      version:
+        description: "Image tag to publish (e.g. 1.1.2); leave blank for just :latest"
+        required: false
+        default: ""
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  image:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Compute lowercase image name
+        id: img
+        run: echo "name=ghcr.io/${GITHUB_REPOSITORY,,}" >> "$GITHUB_OUTPUT"
+
+      - uses: docker/setup-qemu-action@v3
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Docker metadata (tags & labels)
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ steps.img.outputs.name }}
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=raw,value=${{ inputs.version }},enable=${{ github.event_name == 'workflow_dispatch' && inputs.version != '' }}
+            type=raw,value=latest
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.gitignore

@@ -15,6 +15,7 @@ __pycache__/
 
 # Claude Code
 .claude/
+CLAUDE.md
 
 # Gitea token
 .gitea-token
@@ -26,3 +27,6 @@ Thumbs.db
 # Local config — contains the admin password hash and session secret.
 # Fresh installs start from config.json.example (see CONFIG.md).
 config.json
+
+# Docker config volume (holds the live config.json with secrets)
+data/

CHANGELOG.md

@@ -0,0 +1,61 @@
+# Changelog
+
+All notable changes to this project are documented here. The format is based
+on [Keep a Changelog](https://keepachangelog.com/), and this project adheres to
+[Semantic Versioning](https://semver.org/).
+
+## [1.1.2] - 2026-06-10
+
+First release with a published container image and security tooling. No
+application behavior changes from 1.1.1.
+
+### Added
+- Prebuilt multi-arch (amd64 + arm64) container image published to GitHub
+  Container Registry: `ghcr.io/allennpit/ads-bit`.
+- CodeQL code-scanning workflow (Python + JavaScript) and Dependabot updates
+  for GitHub Actions and pip.
+- `workflow_dispatch` trigger on the release workflow for manual image builds.
+
+## [1.1.1] - 2026-06-10
+
+### Added
+- `/health` endpoint (status, version, receiver/flight counts) plus a Docker
+  `HEALTHCHECK`.
+- `ADSBIT_CONFIG` environment variable to override the config file path.
+
+### Changed
+- Docker first-run now works with no manual steps: `config.json` is auto-seeded
+  from `config.json.example` by `docker-entrypoint.sh` and persisted on a
+  `./data` directory mount (removing the single-file bind-mount footgun).
+- Network auto-scan skips subnets larger than `/20` (e.g. a Docker bridge
+  `172.17.0.0/16`) so discovery no longer stalls startup on Docker hosts.
+- `SIGTERM`/`SIGINT` (`docker stop`, `systemctl stop`) shut down cleanly
+  without a stack trace.
+
+## [1.1.0] - 2026-06-09
+
+### Added
+- In-app pixel editor for sprites (admin → Sprites → EDIT): pencil, eraser,
+  color picker, fill bucket, line/rectangle/ellipse shapes, rectangular
+  select with move/cut/copy/paste, reference-image overlay, brush size &
+  opacity, custom + recent palettes, zoom/pan, grid, undo/redo.
+- Receiver health dashboard: live per-receiver status (receiving / no data /
+  unreachable), connection testing, a select → save → apply flow, selectable
+  scan results, and a per-interface scan selector.
+- Version surfaced at startup, via `GET /api/config`, and in the admin header.
+
+### Fixed
+- Server crash when restarting receiver connections: cancelled receiver tasks
+  no longer tear down the main event loop.
+
+## [1.0] - 2026-01
+
+### Added
+- Initial release: retro SNES-style side-view ADS-B flight tracker with custom
+  pixel-art sprites, directional backgrounds, weather, sun/moon, admin panel,
+  first-run setup wizard, and Docker/Podman support.
+
+[1.1.2]: https://github.com/AllenNPIT/ADS-Bit/releases/tag/v1.1.2
+[1.1.1]: https://github.com/AllenNPIT/ADS-Bit/releases/tag/v1.1.1
+[1.1.0]: https://github.com/AllenNPIT/ADS-Bit/releases/tag/v1.1.0
+[1.0]: https://github.com/AllenNPIT/ADS-Bit/releases/tag/v1.0

CLAUDE.md

@@ -1,151 +0,0 @@
-# CLAUDE.md
-
-This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
-
-## Project Overview
-
-ADS-Bit is a retro SNES-style side-view flight tracker that displays ADS-B aircraft data with custom pixel art sprites.
-
-## Running the Server
-
-```bash
-# Start the server (port configured in config.json, default 2001)
-python3 server.py
-
-# Or use the startup script
-./start.sh
-```
-
-Access at http://localhost:{web_port} (configured in config.json)
-
-## Architecture
-
-### Components
-
-- **server.py** - Python WebSocket server using aiohttp
-  - Reads configuration from config.json
-  - Auto-scans for ADS-B receivers or connects to configured IPs
-  - Parses SBS/BaseStation format messages from receivers (port 30003)
-  - Polls dump1090 JSON API (`/dump1090/data/aircraft.json`) every 5s for ADS-B emitter categories
-  - Broadcasts flight data (including emitter category) to WebSocket clients every 1 second
-  - Cleans up flights not seen in 60 seconds
-  - Serves static files, admin panel, setup wizard, and APIs
-  - Authentication via bcrypt password hashing and session cookies
-
-- **config.json** - Configuration file for receiver and location settings
-  - See CONFIG.md for full documentation
-
-- **ads-bit.js** - JavaScript rendering engine (Canvas-based)
-  - Handles WebSocket connection and flight data updates
-  - Renders 10 FPS retro-style canvas animation
-  - Layer order (bottom to top): sky gradient → clouds → sun → moon → directional background → grid → aircraft → labels
-  - Directional backgrounds include horizon, so low sun/moon is realistically occluded
-  - Aircraft sprites flip horizontally when heading west (track 90°-270°)
-  - View direction rotates between N/E/S/W (arrow keys or A/D), changing the background
-
-- **index.html** - Main HTML interface with embedded styles
-
-- **admin/** - Admin panel (login + tabbed settings UI)
-  - Theme management: rename display names, upload per-direction background PNGs, create new themes
-  - Display names stored in `config.json` `theme_names` map (folder name -> display name)
-  - Receivers tab: live per-receiver health (via `GET /api/admin/receiver-status` and `POST /api/admin/test-receivers`), a select → SAVE & APPLY → auto-test flow, selectable scan results, and a per-interface scan selector
-  - Version (from `server.py` `VERSION`) is surfaced via public `GET /api/config` and shown in the admin header
-  - **pixel-editor.js** - In-app Canvas2D pixel editor (Sprites tab "EDIT" button)
-    - Edits sprites at native 500x333; tools: pencil, eraser, color picker, fill bucket, pan, line, rectangle, ellipse (outline/filled), rectangular select
-    - Select & move: marquee + floating layer, drag/arrow-nudge, Ctrl+C/X/V clipboard, Delete, Enter/Esc commit
-    - Zoom/pan, undo/redo (snapshot-per-stroke), grid overlay, brush size & opacity, retro + custom (localStorage) + recent palettes, adjustable reference-image overlay
-    - Exports a 500x333 PNG via `srcCanvas.toBlob` and POSTs to the existing `/api/admin/sprites/{type}` upload endpoint (no new server route)
-    - Keyboard: B/E/I/F/L/R/O/M tools, Space=pan, +/-/0 zoom, Ctrl+Z/Y undo/redo, Ctrl+C/X/V, arrows nudge, G grid, Esc close
-  - **Asset cache-busting:** `admin.html` references `admin.css`/`admin.js`/`pixel-editor.js` with a `?v=YYYYMMDD[x]` query — bump it whenever those files change so browsers reload them
-
-- **setup/** - First-run setup wizard (multi-step configuration)
-
-### Sprite Assets
-
-All PNG sprites face right (eastward) and are flipped in-canvas for westbound aircraft:
-- 9 aircraft types: smallProp, regionalJet, narrowBody, wideBody, heavy, helicopter, balloon, glider, uav
-- Directional backgrounds: north.png, south.png, east.png, west.png (1536x1024, shown based on view direction)
-- Celestial: sun.png, moon_6_phases.png (2x3 sprite sheet)
-- Weather: happycloud.png (clear), raincloud.png (rain/snow)
-
-### Aircraft Type Detection Logic
-
-Two-tier system: real ADS-B emitter categories when available, heuristic fallback otherwise.
-
-#### Tier 1: ADS-B Emitter Category (from dump1090 JSON API)
-
-The server polls `http://{receiver_ip}/dump1090/data/aircraft.json` every 5 seconds. The SBS/BaseStation protocol (port 30003) does **not** include emitter category, but the dump1090/readsb JSON API exposes the raw ADS-B transponder category field. When available, this is authoritative and always preferred over heuristics.
-
-Mapping from DO-260B emitter categories to sprite types:
-| ADS-B Category | Description | Sprite |
-|---|---|---|
-| A1 | Light (< 15,500 lbs) | smallProp |
-| A2 | Small (15,500 - 75,000 lbs) | regionalJet |
-| A3 | Large (75,000 - 300,000 lbs) | narrowBody |
-| A4 | High vortex large (B757) | narrowBody |
-| A5 | Heavy (> 300,000 lbs) | wideBody or heavy (by altitude/speed) |
-| A6 | High performance (> 5g, > 400 kts) | narrowBody |
-| A7 | Rotorcraft | helicopter |
-| B1 | Glider / sailplane | glider |
-| B2 | Lighter-than-air | balloon |
-| B4 | Skydiver drop plane | smallProp |
-| B6 | UAV | uav |
-
-Once an emitter category is received for an aircraft, it is locked in and heuristic re-evaluation is skipped.
-
-#### Tier 2: Heuristic Fallback (when no emitter category available)
-
-Priority order when ADS-B category is not available (some transponders don't broadcast it):
-1. **Helicopter callsigns**: known operator prefixes (LFE, MED, CHP, PHI, ERA, BHS) or keywords (LIFE, MERCY, COPTER, etc.)
-2. **Heavy/Wide body callsigns**: major airline ICAO prefixes (CPA, UAE, ETH, QTR, SIA, AAL, DAL, UAL, FDX, UPS, etc.) + altitude/speed thresholds
-3. **Altitude/speed extremes**: altitude > 42000 ft or speed > 550 kts = heavy; > 40000 ft or > 500 kts = wideBody
-4. **N-number (US GA registration)**: pattern `N` + digit + 2-4 alphanumerics = smallProp (or narrowBody if above 25000 ft)
-5. **Regional airline callsigns**: SKW, RPA, ASH, PDT, CHQ, ENY, JIA, CPZ
-6. **Speed/altitude heuristics**: speed < 60 + alt < 5000 = helicopter; alt < 18000 + speed < 300 = smallProp or regionalJet
-7. **Altitude-only**: < 10000 ft = smallProp, < 25000 ft = regionalJet, higher = narrowBody
-8. **Default**: narrowBody (re-evaluated when better data arrives)
-
-Important: `speed=0` or `altitude=0` means data not yet received, not actual zero. The system re-categorizes when better data arrives (speed > 0 and callsign present).
-
-### View Direction Controls
-
-The viewer can rotate between cardinal directions (N/E/S/W), showing aircraft in a 90° field of view:
-- **Keyboard**: Left/Right arrow keys or A/D keys
-- **UI**: Arrow buttons on the interface
-- Each direction displays a unique background image (north.png, east.png, south.png, west.png)
-- Sun and moon positions are calculated based on actual azimuth and only appear when in the current field of view
-
-### External APIs
-
-- **Open-Meteo**: Weather and sunrise/sunset data (updates every 10 minutes)
-- **ADS-B Receivers**: SBS/BaseStation protocol on port 30003 (flight data)
-- **dump1090 JSON API**: `http://{receiver}/dump1090/data/aircraft.json` on port 80 (emitter categories, polled every 5s)
-
-## Dependencies
-
-Python packages required:
-- aiohttp (web server and WebSocket)
-- netifaces (network interface scanning)
-- bcrypt (password hashing)
-
-No package.json - frontend is vanilla JavaScript with no build step.
-
-## Key Code Patterns
-
-- Canvas version parameter on assets (`?v=36`) for cache busting
-- Aircraft direction: `const isFacingLeft = flight.track > 90 && flight.track < 270`
-- Moon phases use sprite sheet cropping with 2x3 grid (3 columns, 2 rows)
-- Flight data stored in global `flights` dict keyed by ICAO hex code
-
-## Debugging
-
-```bash
-# Check for running server instances
-ps aux | grep server.py
-
-# Kill all instances
-pkill -9 -f server.py
-
-# Test receiver connectivity (replace with your receiver IP)
-nc -zv <receiver_ip> 30003
-```

CONTRIBUTING.md

@@ -0,0 +1,59 @@
+# Contributing to ADS-Bit
+
+Thanks for your interest in improving ADS-Bit! Contributions of all kinds —
+bug reports, features, sprites, themes, docs — are welcome.
+
+## Development setup
+
+ADS-Bit is a Python (aiohttp) backend with a vanilla-JavaScript frontend.
+There is **no build step** for the frontend.
+
+```bash
+git clone <your-fork-url>
+cd ADS-Bit
+pip install -r requirements.txt      # Python 3.9–3.11 recommended (see note below)
+cp config.json.example config.json   # optional; the setup wizard runs otherwise
+python3 server.py                     # serves on http://localhost:2001
+```
+
+Or with Docker (no local Python needed):
+
+```bash
+docker compose up -d
+```
+
+> **Python version note:** the `netifaces` dependency can be hard to build on
+> Python 3.12+. Use Python 3.9–3.11, or just use the Docker image (Python 3.11).
+
+## Project layout
+
+- `server.py` — aiohttp server: receiver connections, flight state, APIs, auth.
+- `ads-bit.js` / `index.html` — Canvas-based retro viewer.
+- `admin/` — admin panel, including the in-browser `pixel-editor.js`.
+- `setup/` — first-run setup wizard.
+- `images/`, `backgrounds/` — sprite and theme assets.
+
+## Conventions
+
+- **Frontend assets are cache-busted** via a `?v=YYYYMMDD[x]` query in
+  `admin/admin.html`. If you change `admin.css`, `admin.js`, or
+  `pixel-editor.js`, bump that token so browsers reload them.
+- The `VERSION` constant in `server.py` is the single source of truth; bump it
+  for releases and add a `CHANGELOG.md` entry.
+- Keep the retro aesthetic (Press Start 2P, blue/gold palette) for UI work.
+- Match the style of surrounding code; no frontend framework or build tooling.
+
+## Submitting changes
+
+1. Fork and create a topic branch (`feature/…`, `fix/…`, `chore/…`).
+2. Make focused commits with clear messages.
+3. Verify locally: the server starts, the page loads, and your change works.
+   For Docker changes, confirm `docker build` succeeds.
+4. Open a pull request describing what changed and how you tested it.
+
+CI will byte-compile the server, validate `config.json.example`, and build the
+Docker image on every PR.
+
+## Reporting bugs / requesting features
+
+Use the issue templates. For security issues, see [SECURITY.md](SECURITY.md).

Dockerfile

@@ -13,9 +13,16 @@ RUN pip install --no-cache-dir -r requirements.txt && \
     rm -rf /var/lib/apt/lists/*
 
 COPY . .
+RUN chmod +x /app/docker-entrypoint.sh
 
 EXPOSE 2001
 
-ENV PYTHONUNBUFFERED=1
+# Persist config on a mounted volume by default (see docker-compose.yml).
+ENV PYTHONUNBUFFERED=1 \
+    ADSBIT_CONFIG=/app/data/config.json
 
-CMD ["python3", "server.py"]
+# Liveness probe against the unauthenticated /health endpoint.
+HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 \
+    CMD python3 -c "import urllib.request,sys; sys.exit(0 if urllib.request.urlopen('http://127.0.0.1:2001/health',timeout=4).status==200 else 1)" || exit 1
+
+ENTRYPOINT ["/app/docker-entrypoint.sh"]

README.md

@@ -1,5 +1,9 @@
 # ADS-Bit
 
+[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)
+[![Release](https://img.shields.io/github/v/release/AllenNPIT/ADS-Bit)](https://github.com/AllenNPIT/ADS-Bit/releases)
+[![CI](https://github.com/AllenNPIT/ADS-Bit/actions/workflows/ci.yml/badge.svg)](https://github.com/AllenNPIT/ADS-Bit/actions/workflows/ci.yml)
+
 A retro SNES-style side-view flight tracker that displays ADS-B aircraft data with custom pixel art sprites.
 
 ![ADS-Bit Screenshot](screenshots/screenshot.png)
@@ -41,17 +45,33 @@ On first run, visit http://localhost:2001 and the setup wizard will guide you th
 
 - [Docker](https://docs.docker.com/get-docker/) with Compose V2, **or** [Podman](https://podman.io/) with `podman-compose`
 
-### First Run
+### Run the prebuilt image (no clone needed)
+
+Once a release is published, a multi-arch image (amd64 + arm64, e.g. Raspberry Pi)
+is available from GitHub Container Registry:
 
 ```bash
-# Create a config file (the setup wizard runs if you skip this)
+docker run -d --name ads-bit --network host --restart unless-stopped \
-cp config.json.example config.json
+  -e ADSBIT_CONFIG=/app/data/config.json \
+  -v "$PWD/data:/app/data" \
+  ghcr.io/allennpit/ads-bit:latest
+```
 
-# Build and start
+Then open http://localhost:2001 and complete the setup wizard.
+
+### Build from source
+
+```bash
+# Build and start — no config step needed
 docker compose up -d
 ```
 
-The web UI is available at http://localhost:2001.
+A config file is created automatically in `data/` on first run, then the
+browser **setup wizard** walks you through receiver, location, and password
+setup. The web UI is available at http://localhost:2001.
+
+A `/health` endpoint (used by the container healthcheck) reports status,
+version, and receiver/flight counts: `curl http://localhost:2001/health`.
 
 ### Useful Commands
 
@@ -82,15 +102,15 @@ The following paths are bind-mounted from the repo directory and persist across
 
 | Path | Contents |
 |------|----------|
-| `config.json` | Server configuration and credentials |
+| `data/` | Server configuration and credentials (`config.json`, auto-seeded) |
 | `images/` | Aircraft and UI sprites (including uploads) |
 | `backgrounds/` | Theme background images (including custom themes) |
 
-Host networking (`network_mode: host`) is used so the server can auto-scan your LAN for ADS-B receivers.
+Host networking (`network_mode: host`) is used so the server can auto-scan your LAN for ADS-B receivers. Auto-scan skips oversized subnets (larger than /20, e.g. a Docker bridge `172.17.0.0/16`); if your receiver lives on such a network, set it explicitly via the admin Receivers tab.
 
 ## Requirements
 
-- Python 3.8+
+- Python 3.9–3.11 (3.12+ may require build tools for `netifaces`; the Docker image uses 3.11)
 - ADS-B receiver providing SBS/BaseStation format on port 30003 (dump1090, readsb, etc.)
 - Modern web browser with Canvas support
 

SECURITY.md

@@ -0,0 +1,35 @@
+# Security Policy
+
+## Supported Versions
+
+| Version | Supported |
+|---------|-----------|
+| 1.1.x   | ✅        |
+| < 1.1   | ❌        |
+
+## Reporting a Vulnerability
+
+Please **do not** open a public issue for security vulnerabilities.
+
+Instead, use GitHub's private vulnerability reporting:
+**Security → Report a vulnerability** on the repository.
+
+Include as much detail as you can:
+- Affected version (see the version in the admin header or `GET /api/config`)
+- Steps to reproduce / proof of concept
+- Impact and any suggested remediation
+
+You can expect an acknowledgement within a few days. Please allow reasonable
+time for a fix before any public disclosure.
+
+## Security Notes for Operators
+
+ADS-Bit is intended for trusted LANs, not direct exposure to the public
+internet. If you must expose it:
+
+- Set a strong admin password (changed from the setup default).
+- Put it behind HTTPS via a reverse proxy or tunnel (e.g. Caddy, nginx,
+  Tailscale). The built-in server speaks plain HTTP.
+- Never commit your `config.json` — it contains the admin password hash and
+  session secret. It is git-ignored by default; fresh installs start from
+  `config.json.example`.

docker-compose.yml

@@ -6,9 +6,11 @@ services:
     restart: unless-stopped
     environment:
       - PYTHONUNBUFFERED=1
+      - ADSBIT_CONFIG=/app/data/config.json
     volumes:
-      # Persist config (copy config.json.example to config.json before first run)
+      # Config persists here; auto-seeded from config.json.example on first run
-      - ./config.json:/app/config.json
+      # (a directory mount, so a fresh `docker compose up` just works).
+      - ./data:/app/data
       # Persist custom sprite uploads
       - ./images:/app/images
       # Persist custom theme backgrounds

docker-entrypoint.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+# Seed a config file on first run so `docker compose up` works on a fresh
+# clone with no manual steps. The config lives on a mounted data volume so it
+# persists across container rebuilds.
+set -e
+
+: "${ADSBIT_CONFIG:=/app/config.json}"
+CONFIG_DIR=$(dirname "$ADSBIT_CONFIG")
+mkdir -p "$CONFIG_DIR"
+
+if [ ! -f "$ADSBIT_CONFIG" ]; then
+    echo "[entrypoint] No config at $ADSBIT_CONFIG — seeding from config.json.example"
+    cp /app/config.json.example "$ADSBIT_CONFIG"
+fi
+
+exec python3 server.py

server.py

@@ -17,10 +17,16 @@ from aiohttp import web, ClientSession, ClientTimeout
 import netifaces
 import bcrypt
 
-VERSION = "1.1.0"
+VERSION = "1.1.2"
 
 WEB_DIR = Path(__file__).parent
-CONFIG_FILE = WEB_DIR / "config.json"
+# Config path is overridable (handy for containers persisting config on a
+# named volume); defaults to config.json next to this script for bare-metal.
+CONFIG_FILE = Path(os.environ.get("ADSBIT_CONFIG") or (WEB_DIR / "config.json"))
+
+# Smallest subnet prefix (largest network) we'll auto-scan: /20 = 4094 hosts.
+# Anything bigger (e.g. a docker /16) is skipped to keep scans fast and safe.
+MIN_SCAN_PREFIX = 20
 
 # Track server start time
 SERVER_START_TIME = time.time()
@@ -414,6 +420,15 @@ async def scan_for_receivers():
                 if ip and netmask and not ip.startswith('127.'):
                     try:
                         network = ipaddress.IPv4Network(f"{ip}/{netmask}", strict=False)
+                        # Skip subnets too large to scan quickly (e.g. a docker
+                        # bridge /16 = 65k hosts). Without this, AUTO discovery
+                        # hammers the network and stalls startup on any host with
+                        # Docker or a large/16. Use MANUAL or a custom subnet for
+                        # receivers that live on such networks.
+                        if network.prefixlen < MIN_SCAN_PREFIX:
+                            print(f"Skipping {network} on {iface}: too large "
+                                  f"({network.num_addresses} hosts) for auto-scan")
+                            continue
                         found.extend(await _scan_subnet(network, port))
                     except ValueError as e:
                         print(f"Invalid network {ip}/{netmask}: {e}")
@@ -984,9 +999,10 @@ async def handle_admin_scan_receivers(request):
             return web.json_response(
                 {"error": f"Invalid subnet: {subnet}"}, status=400)
 
-        if network.prefixlen < 20:
+        if network.prefixlen < MIN_SCAN_PREFIX:
             return web.json_response(
-                {"error": "Subnet too large (max /20 = 4096 hosts)"}, status=400)
+                {"error": f"Subnet too large (max /{MIN_SCAN_PREFIX} = "
+                          f"{2 ** (32 - MIN_SCAN_PREFIX) - 2} hosts)"}, status=400)
 
         port = config['receiver_port']
         found = await _scan_subnet(network, port)
@@ -1172,6 +1188,17 @@ async def handle_http(request):
     return web.Response(status=404, text="Not Found")
 
 
+async def handle_health(request):
+    """GET /health - liveness/readiness probe (no auth, no secrets)."""
+    return web.json_response({
+        "status": "ok",
+        "version": VERSION,
+        "receivers": len(receivers),
+        "flights": len(flights),
+        "uptime_seconds": int(time.time() - SERVER_START_TIME),
+    })
+
+
 # ---------------------------------------------------------------------------
 # Application setup
 # ---------------------------------------------------------------------------
@@ -1184,6 +1211,7 @@ async def start_http_server():
     app.router.add_get('/ws', websocket_handler)
 
     # Public API
+    app.router.add_get('/health', handle_health)
     app.router.add_get('/api/receiver-location', handle_receiver_location)
     app.router.add_get('/api/config', handle_config)
 
@@ -1282,4 +1310,11 @@ async def main():
 
 
 if __name__ == "__main__":
-    asyncio.run(main())
+    # Make SIGTERM (docker stop, systemctl stop) raise KeyboardInterrupt like
+    # SIGINT does, so shutdown is clean and quiet instead of a stack trace.
+    import signal
+    signal.signal(signal.SIGTERM, signal.default_int_handler)
+    try:
+        asyncio.run(main())
+    except (KeyboardInterrupt, SystemExit):
+        print("ADS-Bit server shutting down.")