pass ENV-Variables via ENVIRONMENTS file in .gitlab-ci.yml

.gitlab-ci.yml

 image: ${CI_REGISTRY_IMAGE}/buildimage
 before_script:
-  - export ARCH=all
-  - export VERSION="$(dpkg-parsechangelog -S version)"
-  - export PKGNAME="$(awk '/^Package:/ { print $2 }' debian/control)"
-  - echo $ARCH
-  - echo $VERSION
-  - echo $PKGNAME
+  - echo "ARCH=all" > ENVIRONMENTS
+  - echo "VERSION=$(dpkg-parsechangelog -S version)" >> ENVIRONMENTS
+  - echo "PKGNAME=$(awk '/^Package:/ { print $2 }' debian/control)" >> ENVIRONMENTS
 
 .build-package: &build-package
   stage: test
@@ -13,9 +10,6 @@ before_script:
     # will test, if we can build the package - this also runs the unittests
     # ecause we use python3-setuptools
     - dpkg-buildpackage -uc -us -b
-    - echo $ARCH
-    - echo $VERSION
-    - echo $PKGNAME
 
 test-others:
   <<: *build-package
@@ -30,9 +24,7 @@ build-master:
   <<: *build-package 
   stage: build
   after_script:
-    - echo $ARCH
-    - echo $VERSION
-    - echo $PKGNAME
+    - eval $(cat ENVIRONMENTS)
     - mkdir build
     - ls ../
     - mv ../${PKGNAME}_${VERSION}_${ARCH}.deb build/
@@ -49,6 +41,7 @@ test-and-deploy-master:
   dependencies:
     - build-master
   script:
+    - eval $(cat ENVIRONMENTS)
     - gdebi --non-interactive build/${PKGNAME}_${VERSION}_${ARCH}.deb
   environment:
     name: staging