Use the Gitlab Docker Registry

.gitlab-ci.yml

@@ -24,7 +24,9 @@ build-job: # This job runs in the build stage, which runs first.
   stage: build
   script:
     - echo "Building the Docker image..."
-    - docker-compose build
+    - echo $CI_REGISTRY_PASSWORD | docker login -u $CI_REGISTRY_USER $CI_REGISTRY --password-stdin
+    - docker build -t $CI_REGISTRY_IMAGE .
+    - docker push $CI_REGISTRY_IMAGE
     - echo "Build complete."
 
 unit-test-job: # This job runs in the test stage.