README
¶
ownmap
Please note, this project is still being developed and hasn't reached a point where APIs are stable yet. This means that for the moment, interfaces, file formats, APIs can change without any notice.
The aim of this project is to be able to provide a 1-file program that can generate "slippy" map tiles from openstreetmap PBF files. Ideally it should be able to run (at least serving map tiles) on low-end hard, with a Raspberry Pi-level computer being the target (ideally the Raspberry Pi Zero, but that might be a stretch considering how powerful the hardware is).
The project contains:
- A custom data file format, for storing data in simple, on-disk files, for quick retrieval and map tile creation. (No database creation required.)
- Support for different style types: a custom in-built style and partial support for MapBoxGL styles (with the idea to also support CartoCSS in the future).
- A rasterer: for drawing tile images, given the data and style.
- A web server, for handling a request for fetching a tile, with a given style, and returning the drawn style.
Screenshots
With the default, inbuilt style:
With the "Bright" style from OpenMapTiles.org:
Limitations
Amongst others:
- Coastlines are not handled.
- Limited support for styling.
Dev setup
First you need to download an OSM extract in PBF format. Any compatible files from any website offering them will do. Geofabrik offers some good extracts with small areas you can try out quickly.
Then you should place the downloaded file in data/sample-pbf-file.pbf. Alternatively, you could place a symlink here to another file on the disk.
Then run make run_dev_import. This will read the pbf file and create a ownmapdb file. This contains information from the pbf file, but also sorts the items and contains an index to find things more efficiently given a geographic area. The importer has a progress indicator, so you can calculate roughly how long it will take.
You can then run make run_dev_server__basic_style. This will start a web server. In the logs you can see the address that it is serving on. Open up a web browser and go to that address. You will see an interactive slippy map with tiles being served from your tileserver.
Here's an example. You will need wget, go, and make installed.
mkdir -p data
wget -O data/sample-pbf-file.pbf https://download.geofabrik.de/europe/united-kingdom/england/buckinghamshire-latest.osm.pbf
make run_dev_import
make run_dev_server__basic_style
# now open your web browser and navigate to http://localhost:9000
Profiling
go tool pprof --web ownmap-app /path/to/profile/cpu.pprof > profile_out.html
Directories