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:
If the container exits without errors, then your data has been successfully imported and you are now ready to run the tile server.
## Running the server
Run the server like this:
docker run -p 80:80 -v openstreetmap-data:/var/lib/postgresql/10/main -d overv/openstreetmap-tile-server run
Your tiles will now be available at http://localhost:80/tile/{z}/{x}/{y}.png. If you open `leaflet-demo.html` in your browser, you should be able to see the tiles served by your own machine. Note that it will initially quite a bit of time to render the larger tiles for the first time.
## Preserving rendered tiles
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
## Performance tuning
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
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[126]: ERROR: failed to render TILE ajt 6 32-39 16-23,
renderd[126]: reason: Postgis Plugin: ERROR: could not resize shared memory segment
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.
