Add basic application framework and example application to show interaction between events an NBI

Depends on:

• !340 (merged)
• !344 (merged)
• !349 (merged)
• !342 (merged)

.gitlab/ci/.build-container.yml

@@ -9,14 +9,14 @@
 build-testing-image:
     script:
         - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
-        - docker build -t "$GOSDN_TESTING_IMAGE" -f "${CI_PROJECT_DIR}/controller/Dockerfile" --target "installer" --build-arg "GOLANG_VERSION=$GOLANG_VERSION" --build-arg "BUILDARGS=$BUILDARGS" --build-arg "GITLAB_PROXY=${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/" .
+        - docker buildx build -t "$GOSDN_TESTING_IMAGE" -f "${CI_PROJECT_DIR}/controller/controller.Dockerfile" --target "builder" --build-arg "GOLANG_VERSION=$GOLANG_VERSION" --build-arg "BUILDARGS=$BUILDARGS" --build-arg "GITLAB_PROXY=${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/" .
         - docker push "$GOSDN_TESTING_IMAGE"
     <<: *build
 
 build-image:
     script:
         - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
-        - docker build -t "$CI_REGISTRY_IMAGE:$TAG" -f "${CI_PROJECT_DIR}/controller/Dockerfile" --build-arg "GOLANG_VERSION=$GOLANG_VERSION" --build-arg "BUILDARGS=$BUILDARGS" --build-arg "GITLAB_PROXY=${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/" .
+        - docker buildx build -t "$CI_REGISTRY_IMAGE:$TAG" -f "${CI_PROJECT_DIR}/controller/controller.Dockerfile" --build-arg "GOLANG_VERSION=$GOLANG_VERSION" --build-arg "BUILDARGS=$BUILDARGS" --build-arg "GITLAB_PROXY=${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/" .
         - docker push "$CI_REGISTRY_IMAGE:$TAG"
         # replace all slashes in the tag with hyphen, because slashes are not allowed in tags
         - NEWTAG=${CI_COMMIT_BRANCH//\//-}