first

.gitlab-ci.yml

+stages:
+  - build
+  - deploy
+
+variables:
+  GIT_DEPTH: "1"
+  CONTAINER_TEST_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
+  CONTAINER_RELEASE_IMAGE: $CI_REGISTRY_IMAGE:latest
+
+before_script:
+  - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+
+build:
+  stage: build
+  tags: 
+    - docker
+  script:
+    - docker build --pull -t $CONTAINER_TEST_IMAGE .
+    - docker push $CONTAINER_TEST_IMAGE
+
+deploy_latest:
+  stage: deploy
+  tags: 
+    - docker
+  script:
+    - docker pull $CONTAINER_TEST_IMAGE
+    - docker tag $CONTAINER_TEST_IMAGE $CONTAINER_RELEASE_IMAGE
+    - docker push $CONTAINER_RELEASE_IMAGE
+  only:
+    - master
+
+deploy_tag:
+  stage: deploy
+  tags: 
+    - docker
+  variables:
+    CONTAINER_TAG_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
+  script:
+    - docker pull $CONTAINER_TEST_IMAGE
+    - docker tag $CONTAINER_TEST_IMAGE $CONTAINER_TAG_IMAGE
+    - docker push $CONTAINER_TAG_IMAGE
+  only:
+    - tags

Dockerfile

+FROM debian:buster-slim
+RUN apt update && \
+    apt -y install apt-transport-https lsb-release ca-certificates gnupg2 curl wget && \
+    curl -sL https://nginx.org/keys/nginx_signing.key | apt-key add - && \
+    printf "deb http://yangtze.my-card.in/nginx-plus/debian `lsb_release -cs` nginx-plus\n" | tee /etc/apt/sources.list.d/nginx-plus.list && \
+    apt update && \
+    apt -y install nginx-plus && \
+    rm -rf /var/lib/apt/lists/* /etc/nginx/sites-enabled/* /etc/nginx/conf.d/default.conf /usr/lib/nginx-plus/check-subscription
+COPY ./dummy /usr/lib/nginx-plus/check-subscription
+
+EXPOSE 80 443
+STOPSIGNAL SIGTERM
+CMD ["nginx", "-g", "daemon off;"]

dummy

+#!/bin/sh
+exit 0