[gdal-dev] WFS requests failing with /vsicurl/ against QGIS Server: missing Content-Length header

[Jorge Gustavo Rocha]

Hi,

I'm getting errors with WFS calls to QGIS Server using /vsicurl/. 
Against Geoserver I didn't notice this issue.

I can work on a solution, if the problem is on the QGIS Server side. I 
would love to have a second opinion on this.

What I have found:

1) The is no Content-Length: header in QGIS Server answer:

curl -L -I 
"https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016"
HTTP/1.1 200 OK
Date: Mon, 29 May 2023 22:12:32 GMT
Server: Apache/2.4.41 (Ubuntu)
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: POST, GET, OPTIONS, DELETE, PUT
Access-Control-Max-Age: 1000
Access-Control-Allow-Headers: x-requested-with, Content-Type, origin, 
authorization, accept, client-security-token
Content-Type: text/xml; subtype=gml/2.1.2; charset=utf-8

2) The is a Content-Length: header in Geoserver answer:

curl -L -I 
"https://wssig3.azores.gov.pt/geoserver/ows?service=WFS&request=GetFeature&typename=ef:EnvironmentalMonitoringFacility&version=2.0.0&srsname=EPSG:5015"
HTTP/1.1 200 OK
X-Frame-Options: SAMEORIGIN
Content-Type: application/gml+xml; version=3.2
Content-Disposition: inline; filename=features.xml
Content-Length: 494599
Server: Jetty(9.4.18.v20190429)

Example of testing calls:

This works (without vsicurl):
ogrinfo 
"https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016"
INFO: Open of 
`https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016'
       using driver `GML' successful.
1: ponto_cotado

This does not work:
ogrinfo 
"/vsicurl/https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016" 
--debug on
HTTP: libcurl/7.81.0 OpenSSL/3.0.2 zlib/1.2.11 brotli/1.0.9 zstd/1.4.8 
libidn2/2.3.2 libpsl/0.21.0 (+libidn2/2.3.2) libssh/0.9.6/openssl/zlib 
nghttp2/1.43.0 librtmp/2.3 OpenLDAP/2.5.14
VSICURL: HEAD did not provide file size. Retrying with GET
VSICURL: 
GetFileSize(https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016): 
response_code=200, curl error msg=Failure writing output to destination
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
VSICURL: 
GetFileList(/vsicurl/https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin)
VSICURL: HEAD did not provide file size. Retrying with GET
VSICURL: 
GetFileSize(https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5011): 
response_code=200, curl error msg=Failure writing output to destination
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
ogrinfo failed - unable to open 
'/vsicurl/https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016'.
DGNv8: Driver cleanup

Using docker, I can not use /vsicurl/ with WFS too:
docker run -ti --rm osgeo/gdal ogrinfo 
"/vsicurl/https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016" 
--debug on
HTTP: libcurl/7.81.0 OpenSSL/3.0.2 zlib/1.2.11 brotli/1.0.9 zstd/1.4.8 
libidn2/2.3.2 libpsl/0.21.0 (+libidn2/2.3.2) libssh/0.9.6/openssl/zlib 
nghttp2/1.43.0 librtmp/2.3 OpenLDAP/2.5.13
VSICURL: HEAD did not provide file size. Retrying with GET
VSICURL: 
GetFileSize(https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016): 
response_code=200, curl error msg=Failure writing output to destination
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
VSICURL: 
GetFileList(/vsicurl/https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin)
VSICURL: HEAD did not provide file size. Retrying with GET
VSICURL: 
GetFileSize(https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5011): 
response_code=200, curl error msg=Failure writing output to destination
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
VSICURL: Request at offset 0, after end of file
ogrinfo failed - unable to open 
'/vsicurl/https://irig-madeira.pt/postgresql/drote/public/baram_2020/cgi-bin/qgis_mapserv.fcgi?service=WFS&version=2.0.0&request=GetFeature&typename=ponto_cotado&srsname=EPSG:5016'.

For a Geoserver layer, vsicurl is working:

ogrinfo 
"https://wssig3.azores.gov.pt/geoserver/ows?service=WFS&request=GetFeature&typename=ef:EnvironmentalMonitoringFacility&version=2.0.0&srsname=EPSG:5015"
INFO: Open of 
`https://wssig3.azores.gov.pt/geoserver/ows?service=WFS&request=GetFeature&typename=ef:EnvironmentalMonitoringFacility&version=2.0.0&srsname=EPSG:5015'
       using driver `GML' successful.
1: EnvironmentalMonitoringFacility

Can I assume that the problem is the missing Content-Length header in 
QGIS Server WFS answer? Should I file a bug about this in QGIS?

Regards,

Jorge

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OSGeo Portugal
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