Running the following command:

docker run --rm -it --name simple-webdav -v /data -p 6060:6060 \
-e WD_PORT=6060      \
-e WD_PREFIX='/dav'   \
-e WD_SCOPE='/data'  \
-e WD_AUTH='false'    \
-e WD_MODIFY='true'  \ 
-e WD_DEBUG='true'   \
 hacdias/webdav ''

The WD_AUTH and WD_PREFIX seem to be parsed correctly and the problem i experienced was that the WD_MODIFY and WD_SCOPE were not working, after doing some analysis, the problem might occur because the Permission is nested within Config, while this works for parsing in the default way with flags and config file, it does not work with environment variables.

Possible solution i tried that might work would be to use something like v.BindEnv("field"), looking at the tests of the library used for loading configurations, specifically this one: https://github.com/spf13/viper/blob/cc53fac037475edaec5cd2cae73e6c3cc5caef9e/viper_test.go#L967, seems to fix this nesting issue however that feature is still not shipped.

And as it states in their documentation here, that with AutomaticEnv only loads the value when a v.Get("FIELD") is called, and they probably do not call it for the nested structures, when they get the keys it only reads the 'outside' values during unmarshaling.