Gitlab CI for ASP.Net Core project

.gitlab-ci.yml

image: microsoft/aspnetcore-build:1.1

variables:
  PROJECT_DIR: "app"

cache:
  key: "$CI_PROJECT_NAMESPACE/$CI_PROJECT_NAME"
  paths:
    - .nuget/

build:
  stage: build
  script: 
    - dotnet restore --packages .nuget/packages
    - dotnet publish -c Release -o obj/Docker/publish
  artifacts:
    expire_in: 1 month
    paths:
      - $PROJECT_DIR/obj/Docker/publish/*
 
deploy:
  stage: deploy
  image: docker:latest
  only:
    - tags
  script:
    - cd $PROJECT_DIR/
    - docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN $CI_REGISTRY
    - docker build -t $CI_REGISTRY_IMAGE:$CI_BUILD_TAG .
    - docker push $CI_REGISTRY_IMAGE:$CI_BUILD_TAG