[ci] adapt to images from docker-ci repository

.gitlab-ci.yml

 stages:
   - trigger pipelines
 
+variables:
+  IMAGE_REGISTRY_URL: $CI_REGISTRY/dumux-repositories/dumux-docker-ci
+
 # rules for the default triggers:
-# - pipelines are triggered for commits to master, tags, merge requests
-# - Within merge requests, we require to start the pipeline manually
-#   by clicking play for the trigger
+# - pipelines are triggered for commits to master, tags, merge requests, external triggers
+# - Within merge requests, we require to start the pipeline manually by clicking play for the trigger
 .default-trigger:
   stage: trigger pipelines
   trigger:
@@ -17,12 +19,7 @@ stages:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"
       when: manual
 
-debian11-gcc9-cpp20:
-  extends: .default-trigger
-  variables:
-    IMAGE: registry.dune-project.org/docker/ci/dune:2.7-debian-11-gcc-9-20
-
-ubuntu18.04-clang6-cpp17:
+full-dune-2.7-gcc:
   extends: .default-trigger
   variables:
-    IMAGE: registry.dune-project.org/docker/ci/dune:2.7-ubuntu-18.04-clang-6-17
+    IMAGE: $IMAGE_REGISTRY_URL/full:dune-2.7-gcc-ubuntu-20.04

.gitlab-ci/default.yml

 default:
   image: $IMAGE
 
-cache:
-  key: ${CI_COMMIT_REF_SLUG}-$IMAGE
-  paths:
-    - dep_modules
-
 stages:
   - build
   - test
@@ -17,39 +12,31 @@ workflow:
 build lecture:
   stage: build
   before_script:
-    - mkdir -p dep_modules
-    - pushd dep_modules
-    - >
-      if [ ! -d dune-foamgrid ]; then
-        git clone -b releases/2.7 --depth 1 https://gitlab.dune-project.org/extensions/dune-foamgrid.git;
-        dunecontrol --opts=/duneci/dune.opts --only=dune-foamgrid all;
-      fi
-    - >
-      if [ ! -d dune-alugrid ]; then
-        git clone -b releases/2.7 --depth 1 https://gitlab.dune-project.org/extensions/dune-alugrid.git;
-        dunecontrol --opts=/duneci/dune.opts --make-options="-j8" --only=dune-alugrid all;
+    - |
+      if [ ! "${DUMUX_BRANCH}" ]; then
+        DUMUX_BRANCH=master;
+      else
+        echo "Received branch name ${DUMUX_BRANCH} from upstream"
       fi
-    - >
-      if [ ! -d dumux ]; then
-        git clone -b master --depth 1 https://git.iws.uni-stuttgart.de/dumux-repositories/dumux.git;
-        dunecontrol --opts=/duneci/dune.opts --only=dumux all
-      fi
-    - popd
+    - echo "Checking out branch ${DUMUX_BRANCH} in dumux"
+    - git clone -b ${DUMUX_BRANCH} --depth 1 https://git.iws.uni-stuttgart.de/dumux-repositories/dumux.git
+    - dunecontrol --opts=$DUNE_OPTS_FILE --only=dumux all
   script:
-    - cd ..
-    - dunecontrol --opts=/duneci/dune.opts --only=dumux-lecture all
-    - cd dumux-lecture/build-cmake
-    - make -k -j 8 build_tests
+    - dunecontrol --opts=$DUNE_OPTS_FILE --current all
+    - dunecontrol --opts=$DUNE_OPTS_FILE --current bexec make -k -j4 build_tests
   artifacts:
     paths:
       - build-cmake
+      - dumux
     expire_in: 3 hours
 
 test lecture:
   stage: test
   script:
-    - cd build-cmake
-    - duneci-ctest -j4 --no-tests=error
+    - dunecontrol --opts=$DUNE_OPTS_FILE --current bexec dune-ctest -j4 --output-on-failure
   needs:
     - job: build lecture
       artifacts: true
+  artifacts:
+    reports:
+      junit: junit/dumux-lecture-cmake.xml