[!74] [CI] Configure ccache in .gitlab-ci.yml

Merge branch 'configure-ccache-in-ci' into 'master'

This supercedes relying on configuration in the Docker images, see [#29]

See merge request [joe/pacxx-docker!74]

  [#29]: gitlab.dune-project.org/joe/pacxx-docker/issues/29
  [joe/pacxx-docker!74]: gitlab.dune-project.org/joe/pacxx-docker/merge_requests/74

.gitlab-ci.yml

@@ -13,6 +13,10 @@ stages:
 - test
 - deploy
 
+# we can't simply pass PATH as a variable since that would ignore values set
+# in the image
+.ccache: &ccache export PATH="/usr/lib/ccache:$PATH" CCACHE_DIR=/cache/ccache; ccache -s
+
 .dind: &dind
   image: registry.dune-project.org/joe/registry-cli/docker:master
   services:
@@ -151,6 +155,7 @@ pacxx-build-native:
   variables:
     GIT_STRATEGY: none
   script:
+  - *ccache
   - cat llvm/repoversions
   - mkdir build
   - cd build
@@ -159,6 +164,8 @@ pacxx-build-native:
   - cd ..
   - make DESTDIR=$(pwd) -C build -j$(nproc) install
   - cp llvm/repoversions opt/pacxx/
+  after_script:
+  - *ccache
   artifacts:
     paths:
     - opt/pacxx/
@@ -174,6 +181,7 @@ pacxx-build-cuda:
   variables:
     GIT_STRATEGY: none
   script:
+  - *ccache
   - cat llvm/repoversions
   - mkdir build
   - cd build
@@ -182,6 +190,8 @@ pacxx-build-cuda:
   - cd ..
   - make DESTDIR=$(pwd) -C build -j$(nproc) install
   - cp llvm/repoversions opt/pacxx/
+  after_script:
+  - *ccache
   artifacts:
     paths:
     - opt/pacxx/
@@ -273,10 +283,13 @@ stop-mkimage:
   variables:
     GIT_STRATEGY: none
   before_script:
+  - *ccache
   - cat /opt/pacxx/repoversions
   - cat samples/repoversions
   - mkdir bsamples
   - cd bsamples
+  after_script:
+  - *ccache
   tags:
   - hpc2seci
   artifacts:
@@ -323,9 +336,12 @@ samples-build-cuda-make-release:
     GIT_STRATEGY: none
     PACXX_FORCE_DEFAULT_RT: 1
   before_script:
+  - *ccache
   - cat /opt/pacxx/repoversions
   - cat samples/repoversions
   - cd bsamples
+  after_script:
+  - *ccache
 
 test-native-norv-debug:
   <<: *test