Server (MapServer) does not support the gml coverage

Question

I'm testing WCS (2.0.1) through OGC compliance test and some of the test cases are getting failed with an error: The server does not support the gml coverage.

Test case id : cs2:get-kvp-core-req12

Assertion: req12: For all WCS request types, test the request version parameter has a fixed value of '2.0.1' by GetKVP.

Message d9183e2208_1: [MESSAGE] The server does not support the gml coverage.

Result: Failed

Any suggestions to solve this issue.

Answer 1

It would help a lot to mention where to get the test suite https://github.com/opengeospatial/ets-wcs20

and which exact test you run, and also study the test suite and try to analyze what is probably happening.

I did some fast research.

Failure message is referring to GML Coverage format. By WCS 2.0 core standard WCS 2.0 servers are not required to support this format:

while GML constitutes the canonical format for the definition of WCS, it is not required by this core that a concrete instance of a WCS service implements the GML coverage format

The failing test probably starts from this place in the core2main.xml:

<ctl:call-test name="wcs2:req12">
                        <ctl:with-param name="url" select="$url"/>
                        <ctl:with-param name="Capabilities" select="$response"/>
                        <ctl:with-param name="SupportsGML" select="$SupportsGML"/>
                    </ctl:call-test>

In the WCS 2.0 standard the test for requirement 12 is defined as:

A.1.12 Version number Test id: /conf/core/version-number Test Purpose: Requirement /req/core/version-number: For all WCS request types, the request version parameter shall have a fixed value of “2.0.1”.

Test method: For each request type, send valid requests to server under test. Modulate version parameter:

• Set parameter value to what is required. Verify that request succeeds.

• Set parameter value to a different value. Verify that request fails.

Overall test passes if all individual tests deliver the result expected.

I can't say why the test fails. Test should be testing version number and according to the message it fails because a non-mandatory support for GML coverages is missing. Perhaps the initial error happens already before when "SupportsGML" is tested. If test interprets that the answer is TRUE even it in definitely FALSE with MapServer then strange things could happen in the next tests.