Potential Service Initialization Race Condition #1246
Description
Hello!
When porting an older app (Mapproxy v1.12 , Python 2.7) to a more modern version (Mapproxy v3.1.1, Python 3.12), I noticed that the Coordinate-System Picker for a given WMS layer wasn't respecting what I had set in my YAML.
Somewhat minimal YAML to reproduce:
services:
demo:
wms:
md:
title: "foo"
abstract: "bar"
online_resource: https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9
srs:
- "EPSG:3857"
image_formats:
- "image/jpeg"
wmts:
restful: true
kvp: true
restful_template: /{Layer}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.{InfoFormat}
sources:
esri_world_imagery:
type: tile
grid: default
url: https://services.arcgisonline.com/arcgis/rest/services/World_Imagery/MapServer/WMTS/tile/1.0.0/World_Imagery/default/default/%(z)s/%(y)s/%(x)s.%(format)s
caches:
esri_cache:
sources: [esri_world_imagery]
grids: [default]
cache:
type: file
layers:
- name: '0'
title: World Imagery
sources: [esri_cache]
grids:
default:
base: GLOBAL_WEBMERCATOR
bbox: [-19971868.8804, -20037507.0672, 19971868.8804, 20037507.0672]
Produces a Demo Page with the following CRS options:
- EPSG:3857
- EPSG:4258
- EPSG:4326
- EPSG:900913
- CRS:84
The WMS capabilities doc and actual WMS server seem correct in only listing/allowing CRS:84 & EPSG:3857.
After a good bit of digging, I tracked down where I think the issue is occurring in ServiceConfiguration.services of "mapproxy/config/loader.py". The Demo service gets initialized before the WMS service and srs = self.context.globals.get_value('srs', ...) ends up getting set to the defaults defined in "mapproxy/config/defaults.py"
When placing the the Demo Service somewhere after WMS in the YAML, the options work as expected. i.e.
services:
wms:
md:
title: "foo"
abstract: "bar"
online_resource: https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9
srs:
- "EPSG:3857"
image_formats:
- "image/jpeg"
wmts:
restful: true
kvp: true
restful_template: /{Layer}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.{InfoFormat}
demo:
# ...I'm not sure if this oddity happens in the newer versions or if it even is a "bug" rather than user-error, but I though I'd mention it here just in case.