This container allows you to easily set up an OpenStreetMap PNG tile server given a `.osm.pbf` file. It is based on the [latest Ubuntu 18.04 LTS guide](https://switch2osm.org/manually-building-a-tile-server-18-04-lts/) from [switch2osm.org](https://switch2osm.org/) and therefore uses the default OpenStreetMap style.
## Setting up the server
First create a Docker volume to hold the PostgreSQL database that will contain the OpenStreetMap data:
docker volume create openstreetmap-data
Next, download an .osm.pbf extract from geofabrik.de for the region that you're interested in. You can then start importing it into PostgreSQL by running a container and mounting the file as `/data.osm.pbf`. For example:
Your tiles will now be available at `http://localhost:80/tile/{z}/{x}/{y}.png`. The demo map in `leaflet-demo.html` will then be available on `http://localhost:80`. Note that it will initially quite a bit of time to render the larger tiles for the first time.
Tiles that have already been rendered will be stored in `/var/lib/mod_tile`. To make sure that this data survives container restarts, you should create another volume for it:
docker volume create openstreetmap-rendered-tiles
docker run -p 80:80 -v openstreetmap-data:/var/lib/postgresql/10/main -v openstreetmap-rendered-tiles:/var/lib/mod_tile -d overv/openstreetmap-tile-server run
The import and tile serving processes use 4 threads by default, but this number can be changed by setting the `THREADS` environment variable. For example:
docker run -p 80:80 -e THREADS=24 -v openstreetmap-data:/var/lib/postgresql/10/main -d overv/openstreetmap-tile-server run
You can find an example of the import performance to expect with this image on the [OpenStreetMap wiki](https://wiki.openstreetmap.org/wiki/Osm2pgsql/benchmarks#debian_9_.2F_openstreetmap-tile-server).
If you encounter such entries in the log, it will mean that the default shared memory limit (64 MB) is too low for the container and it should be raised:
renderd[121]: ERROR: failed to render TILE ajt 2 0-3 0-3
renderd[121]: reason: Postgis Plugin: ERROR: could not resize shared memory segment "/PostgreSQL.790133961" to 12615680 bytes: ### No space left on device
To raise it use `--shm-size` parameter. For example:
docker run -p 80:80 -v openstreetmap-data:/var/lib/postgresql/10/main --shm-size="192m" -d overv/openstreetmap-tile-server run
For too high values you may notice excessive CPU load and memory usage. It might be that you will have to experimentally find the best values for yourself.
