Run build job recipes in parallel

Reduce number of CPUs available to DIND runner

.gitlab-ci.yml

@@ -2,7 +2,7 @@ variables:
   DUNE_CONTROL_PATH: /opt/dune:$CI_PROJECT_DIR
   DUNECONTROL: ./dune-common/bin/dunecontrol
   CPUS_MULTICORE: 4
-  CPUS_DIND: 3
+  CPUS_DIND: 2
   DOCKER_LOGIN:
     docker login -u $DOCKER_HUB_USER -p $DOCKER_HUB_PW
   DUNE_ENV_IMAGE:
@@ -10,6 +10,8 @@ variables:
   CMAKE_FLAGS:
     -DDUNE_PYTHON_VIRTUALENV_SETUP=True
     -DDUNE_PYTHON_ALLOW_GET_PIP=True
+  MAKE_FLAGS:
+    -j $CPUS_MULTICORE
 
 image: $DUNE_ENV_IMAGE
 
@@ -86,7 +88,7 @@ build:system-tests: &build-tests
   script:
     - CMAKE_FLAGS="$CMAKE_FLAGS"
       $DUNECONTROL --only=dorie configure
-    - $DUNECONTROL --only=dorie make build_system_tests
+    - $DUNECONTROL --only=dorie make $MAKE_FLAGS build_system_tests
     - $DUNECONTROL --only=dorie make doc
   artifacts:
     name: "$CI_JOB_NAME"
@@ -100,7 +102,7 @@ build:unit-tests:
     - CMAKE_FLAGS="$CMAKE_FLAGS
                    -DCMAKE_BUILD_TYPE=Debug"
       $DUNECONTROL --only=dorie configure
-    - $DUNECONTROL --only=dorie make build_unit_tests
+    - $DUNECONTROL --only=dorie make $MAKE_FLAGS build_unit_tests
 
 build:debug: &debug
   stage: build
@@ -111,7 +113,7 @@ build:debug: &debug
         -DCMAKE_BUILD_TYPE=Debug 
         -DCMAKE_CXX_FLAGS_DEBUG='-Werror'"
       $DUNECONTROL --only=dorie configure
-    - $DUNECONTROL --only=dorie make build_unit_tests
+    - $DUNECONTROL --only=dorie make $MAKE_FLAGS build_unit_tests
 
 build:debug-clang:
   <<: *debug
@@ -124,7 +126,7 @@ build:debug-clang:
         -DCMAKE_CXX_COMPILER=clang++
         -DCMAKE_CXX_FLAGS_DEBUG='-Werror'"
       $DUNECONTROL --only=dorie configure
-    - $DUNECONTROL --only=dorie make build_unit_tests
+    - $DUNECONTROL --only=dorie make $MAKE_FLAGS build_unit_tests
 
 
 # --- Tests ---