ots

OpenStreetMap Tile Server (OTS)

OTS is a server that loads OpenStreetMap data file (*.osm.pbf) into memory then generates map tiles for HTTP requests.

Compile & Packaging

• checkout source codes

$ git clone https://github.com/OutOfBedlam/ots.git

$ cd ots

• compiled executable binary will be created in ./tmp

$ make

Start OTS as tile-rendering-server and OSM data-server in a process

You need to download osm.pbf file from OpenStreetMap sites
https://wiki.openstreetmap.org/wiki/Planet.osm#Country_and_area_extracts

Current version of OTS loads whole map data into memory, so make sure your osm.pbf file is size enough to fit system memory.

./tmp/ots server -p 1918 -i ./tmp/my-area.osm.pbf 

sequenceDiagram
autonumber
   Note over Browser, OTS: HTTP (ex: leaflet.js)
   Browser ->>+ OTS : http://server_addr/tiles/{z}/{x}/{y}.png
   OTS->>OTS: Convert coords
   OTS->>OTS: Retrieve map data
   OTS->>OTS: Gen image
   OTS ->>- Browser: .png

Start tile-rendering-server and data-server

• start a process as a data-server

./tmp/ots server -p 1918 -i ./tmp/my-area.osm.pbf 

• start tile-rendering-server

Specify the endpoint of data-server instead of *.osm.pbf file with -i

./tmp/ots server -p 1919 -i tcp://127.0.0.1:1918

• then web browser can retrieve map tiles as following flow

Web browser --> 127.0.0.1:1919 (rendering server) --> 127.0.0.1:1918 (data server)

sequenceDiagram
autonumber
   Note over Browser, Render-Server: HTTP (ex: leaflet.js)
   Browser ->>+ Render-Server : http://server_addr/tiles/{z}/{x}/{y}.png
   Render-Server->>Render-Server: Convert coords
   Render-Server ->>+ Data-Server : request map data with lat/lon bounds
   Note over Render-Server, Data-Server: GRPC
   Data-Server ->>- Render-Server: map data (osm features)
   Render-Server->>Render-Server: Gen image
   Render-Server ->>- Browser: .png

Configuration file

edit and copy server-config-sample.hcl, keep file extension as *.hcl. then apply the path with -c argument.

./tmp/ots server -c <config_file.hcl>

config file items

rendering server only items

All items in config file can be override by command line arguments. the name of argument is same as config item with double dash --. For example, to override port number ots -c my-config.hcl --port=2929, port number 2929 will be applied.

Where to download *.osm.pbf files

ex) Download south korean osm.pbf file

• https://download.geofabrik.de/asia/south-korea.html

• OSM data up to 2022-04-17T20:21:54Z. File size: 148 MB;

• https://wiki.openstreetmap.org/wiki/Planet.osm#Country_and_area_extracts

References about osm.pbf files

• https://wiki.openstreetmap.org/wiki/Elements

• https://wiki.openstreetmap.org/wiki/PBF_Format

• Nodes : https://wiki.openstreetmap.org/wiki/Node

• Ways : https://wiki.openstreetmap.org/wiki/Way

• Relations : https://wiki.openstreetmap.org/wiki/Relation