wmts-kvp-to-restful

Purpose

WMTS-KVP-to-RESTful is a WMTS RESTful proxy that rewrites WMTS KVP requests to WMTS RESTful requests.

Template used: original-path/{layer}/{tilematrixset}/{tilematrix}/{tilecol}/{tilerow}.{translated format}

Example

/tiles/service/wmts?layer=brtachtergrondkaart&style=default&tilematrixset=EPSG:28992&Service=WMTS&Request=GetTile&Version=1.0.0&Format=image/png&TileMatrix=04&TileCol=7&TileRow=8

becomes

/tiles/service/wmts/brtachtergrondkaart/EPSG:28992/04/7/8.png

A request that cannot be rewriten is passed through unhandled.

Geowebcache issue

The WMTS-KVP-to-RESTful proxy will try to solve the issue with Geowebcache WMTS KVP generated requests. The issue is that the tilematrix values generated contain the tilematrixset as a prefix. This something that doesn't match well with a WMTS RESTful request. This is a issue that some are experiencing and that we ourself have experienced, especially when services are migrated from Geowebcache to a new WMTS server (like mapproxy).

An invalid WMTS RESTful path would generate, the WMTS KVP request:

/ws/raadpleegdiensten/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=grb_bsk_grijs&STYLE=&TILEMATRIXSET=BPL72VL&TILEMATRIX=BPL72VL:11&TILEROW=1072&TILECOL=730&FORMAT=image/png

becomes

/ws/raadpleegdiensten/wmts/grb_bsk_grijs/BPL72VL/BPL72VL:11/730/1072.png

With an incorrect tilematrix value of BPL72VL:11 instead of 11. Through a regex the prefix will be stripped from the tilematrix value.

Tech

test

go test ./...

run

go run . -host=https://geodata.nationaalgeoregister.nl -t=./example/WMTSCapabilities.template.xml -l=true

build

go build .

WMTS Capabilities

WMTS requests come in 3 flavours: GetTile, GetCapabilities and GetFeatureInfo requests. While the main focus of the wmts-kvp-to-restful application is rewriting the GetTile request, the other two requesttypes still part of the WMTS KVP spec. So when starting the application there is the option in setting an template for the WMTS GetCapabilities request.

-t=./path/to/template/WMTSCapabilities.template.xml

An example of this template can be found in the example dir.

docker

docker build -t pdok/wmts-kvp-to-restful .
docker run -v /example:/example --name wmts-proxy -d -p 9001:9001 pdok/wmts-kvp-to-restful /wmts-kvp-to-restful -host=https://geodata.nationaalgeoregister.nl -t=./example/WMTSCapabilities.template.xml -l=true
docker stop wmts-proxy
docker rm wmts-proxy

docker-compose

docker-compose up
docker-compose down