Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -26,6 +26,11 @@ variables:
 build-job:       # Building jar file
   image: maven:3.6.3-jdk-11-slim
   stage: build
+  variables:
+    MAVEN_OPTS: "-Dmaven.repo.local=${CI_PROJECT_DIR}/.repository/"
+  cache:
+    key: maven
+    paths: [.repository/]
   script:
     - mvn clean install -DskipTests && mvn package -B -e -DskipTests
     - export
@@ -40,7 +45,7 @@ publish-job:       # Building docker image and publishing it
     - docker:dind
   script:
     - docker login $DOCKER_URL -u $DOCKER_USER -p $DOCKER_PW
-    - docker build -t $DOCKER_URL/$TAG_LATEST .
+    - docker build -t $DOCKER_URL/$TAG_LATEST --cache-from $DOCKER_URL/$TAG_LATEST .
     - docker push $DOCKER_URL/$TAG_LATEST
 
 deploy-job:      # Deploy docker image on ssh server