add test for using '--overlay-tool unionfs' option for eessi_container.sh

Author: boegel

.github/workflows/test_eessi_container_script.yml

@@ -21,6 +21,7 @@ jobs:
         - shell
         - container
         - resume
+        - unionfs
         # FIXME disabled because '--access rw' is not working in CI environment
         #- readwrite
         #- save
@@ -135,6 +136,13 @@ jobs:
 
                 tar tfv test-save.tar | grep "overlay-upper/${fn}"
 
+              # test use of --overlay-tool unionfs
+              elif [[ ${{matrix.SCRIPT_TEST}} == 'unionfs' ]]; then
+                container="docker://ghcr.io/eessi/build-node:debian12"
+                ./eessi_container.sh --verbose --container ${container} --access rw --overlay-tool unionfs --mode run ls -ld /cvmfs*/software.eessi.io/* 2>&1 | tee ${outfile}
+                grep "/cvmfs/software.eessi.io/versions" $outfile
+                grep "/cvmfs_ro/software.eessi.io/versions" $outfile
+
               else
                   echo "Unknown test case: ${{matrix.SCRIPT_TEST}}" >&2
                   exit 1