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Interactive Viewer

map_data_viewer launches a local Flask web server with a Leaflet-based map UI. It lets you inspect and edit parsed features, view their OSM tags, draw manual annotations, and plan paths — without needing ROS2.

Live demo

A read-only demo of the viewer (Buchlovice dataset) runs at https://vras-robotour.github.io/map_data/demo/ — no install needed. It is rebuilt automatically from the current code on every push. Editing, OSM fetching, path planning, and the tracker require running map_data_viewer locally.

Running the Viewer

# After colcon build and sourcing the workspace:
map_data_viewer

# Explicit data directory and port:
map_data_viewer --data-dir /path/to/data --port 8080

# Standalone (outside a colcon workspace):
python -m map_data.viewer.app --data-dir ./data

Then open http://127.0.0.1:5000 in a browser.

Trusted networks only

By default the viewer has no authentication and its API can read and write files in the data directory. Keep the default --host 127.0.0.1; only bind to other interfaces (e.g. --host 0.0.0.0) on networks where you trust every machine, and see Deployment Security below for options to lock it down further.

Command-line Flags

Flag Default Description
--data-dir <path> package data/ folder Directory to load .mapdata/.gpx files from and save new ones to
--host <address> 127.0.0.1 Address the Flask server binds to
--port <port> 5000 Port the Flask server binds to
--telemetry-rate <Hz> 2.0 Tracker telemetry broadcast rate; see Tracker

Deployment Security

The viewer is safe by default: it binds to 127.0.0.1 (loopback only), rejects file paths that try to escape the data directory, and never unpickles untrusted data. When you run it with --host 0.0.0.0 (or any other non-loopback address) so a robot or a teammate's machine can reach it, keep in mind that anyone who can reach the port has full use of the API — no authentication is required by default. Concretely, that surface includes:

  • Creating/overwriting files in the data directory (/api/fetch_area, /api/upload_gpx, /api/upload_mapdata, and annotation/edit endpoints).
  • Spawning a wormhole send subprocess (/api/create_wormhole).
  • Triggering outbound Overpass API queries on your behalf (/api/fetch_area, .gpx loads).

Only bind to 0.0.0.0 on networks you trust (e.g. an isolated robot LAN). For extra protection on top of that, two environment variables are available:

Variable Default Effect
MAP_DATA_ACCESS_TOKEN unset (auth disabled) When set, every HTTP request and SocketIO connection must supply this exact token, or it's rejected with 401.
MAP_DATA_CORS_ORIGINS unset (same-origin only) Controls which origins may open a SocketIO connection to the server.

MAP_DATA_ACCESS_TOKEN — opt-in, off by default so existing setups and tests are unaffected. When set, the token can be supplied any of three ways:

  • Header: X-Access-Token: <token> (the natural choice for headless/robot API clients).
  • Query parameter: http://host:5000/?access_token=<token>.
  • Cookie: map_data_access_token, set automatically after a request authenticates via the query parameter above — this lets the browser UI authenticate once by visiting the URL with ?access_token=... and have the browser carry that cookie on all subsequent same-origin page, static asset, API, and SocketIO requests. No login UI is involved.

The cookie is set without Secure (so it also works over plain HTTP on a LAN) — if the network itself isn't trusted, put a TLS-terminating reverse proxy in front of the viewer rather than relying on the token alone.

MAP_DATA_CORS_ORIGINS — controls SocketIO's cors_allowed_origins. Left unset, only the request's own origin is allowed (safe default, and it works out of the box for local dev regardless of which port you pick, since it's derived per-request rather than hardcoded). Set it to a comma-separated list of allowed origins to widen access (e.g. when serving the frontend from a different host/port), or to * to explicitly allow any origin. * is never the default — it must be requested explicitly.

Example hardened robot deployment:

export MAP_DATA_ACCESS_TOKEN=$(openssl rand -hex 32)
export MAP_DATA_CORS_ORIGINS=http://192.168.1.50:5000
map_data_viewer --host 0.0.0.0 --data-dir /path/to/data

Tile Layer API Keys

The index page reads THUNDERFOREST_API_KEY and SEZNAM_API_KEY from the environment and makes them available to the page for the corresponding optional basemap tile layers. Export the relevant variable before launching the viewer to enable it:

export THUNDERFOREST_API_KEY=your_key_here
export SEZNAM_API_KEY=your_key_here
map_data_viewer

Both are optional — without them the viewer still works, using the built-in OpenStreetMap and Satellite base layers (see Viewer).

Loading Map Data

The viewer loads files from its data directory (default: the package data/ folder, overridable with --data-dir). Supported file formats:

  • .mapdata — pre-parsed map files created by create_mapdata. Loaded immediately with no network request.
  • .gpx — raw GPS tracks. The viewer parses them on load by fetching OSM data for the track bounds.

You can also drag and drop a .gpx file directly onto the map.

Modes

The viewer has three modes, switched via the tabs in the top-right corner:

Mode Description
Viewer Inspect features, manage layers, draw manual annotations.
Planner Design missions and plan paths using graph-based or all-terrain algorithms.
Tracker Monitor a live robot via ROS2 telemetry. Requires a running ROS2 context.