I took a look at the docker tools, and it looks like we can build an “everything” docker image, or a docker image per test suite. The process is slightly annoying, perhaps we want to publish our versions of the tests to an OSGEO Maven repo.
We don’t really care about “everything” in terms of ETS, so it might help to narrow the problem if we can exclude and prioritise tests suites (either for the "everything" case, or for per-suite docker images).
As a starting point for discussion, here is my opinion, noting that some of the DGIWG and NSG stuff might be "special case". From (one of) the pom.xml:
<ets-wcs10.version>1.13</ets-wcs10.version> - Priority 2
<ets-wcs11.version>1.12</ets-wcs11.version> - Priority 2
<ets-wcs20.version>1.12</ets-wcs20.version> - Priority 2
<ets-wfs10.version>1.12</ets-wfs10.version> - Priority 2
<ets-wfs11.version>1.32</ets-wfs11.version> - Priority 2
<ets-wfs20.version>1.29</ets-wfs20.version> - Priority 1
<ets-wfs30.version>0.1-SNAPSHOT</ets-wfs30.version> - Priority 4
<ets-wms11.version>1.16</ets-wms11.version> - Priority 1
<ets-wms13.version>1.24</ets-wms13.version> - Priority 1
<ets-wmts10.version>1.1</ets-wmts10.version> - Priority 3
<ets-csw202.version>1.17</ets-csw202.version> - Priority 3
<ets-cat30.version>1.1</ets-cat30.version> - No support?
<ets-gml32.version>1.25</ets-gml32.version> - Priority 4
<ets-gpkg10.version>1.0</ets-gpkg10.version> - Priority 3
<ets-gpkg12.version>0.3</ets-gpkg12.version> - Priority 4
<ets-kml22.version>1.12</ets-kml22.version> - Priority 3
<ets-kml2.version>0.5</ets-kml2.version> - No support?
<ets-owc10.version>0.1</ets-owc10.version> - No support?
<ets-sensorml10.version>0.8</ets-sensorml10.version> - No support
<ets-sensorml20.version>0.8</ets-sensorml20.version> - No support
<ets-sfs11.version>1.6</ets-sfs11.version> - No support
<ets-sfs12.version>1.4</ets-sfs12.version> - No support
<ets-sos10.version>1.13</ets-sos10.version> - No support
<ets-sos20.version>1.13</ets-sos20.version> - No support
<ets-sps10.version>1.7</ets-sps10.version> - No support
<ets-sps20.version>1.10</ets-sps20.version> - No support
<ets-sta10.version>1.0</ets-sta10.version> - No support
<ets-wms-client13.version>1.3</ets-wms-client13.version> - Priority 4
<ets-wps10.version>0.6</ets-wps10.version> - Priority 3
<ets-wfs20-dgiwg.version>0.4</ets-wfs20-dgiwg.version> - No support?
<ets-wms13-dgiwg.version>0.4</ets-wms13-dgiwg.version> - No support?
<ets-wms13-nsg.version>0.1</ets-wms13-nsg.version> - No support?
<ets-wfs20-nsg.version>0.3</ets-wfs20-nsg.version> - No support?
<ets-wmts10-nsg.version>0.2</ets-wmts10-nsg.version> - No support?
<ets-gpkg12-nsg.version>0.3</ets-gpkg12-nsg.version> - No support?
<ets-cat20-dgiwg10.version>0.1-SNAPSHOT</ets-cat20-dgiwg10.version> - No support?