Added Gitlab's CI/CD pipeline (.gitlab-ci.yml) for automation.

.gitlab-ci.yml

@@ -0,0 +1,21 @@
+variables:
+  UBUNTU_VER: "22.04"
+
+build:
+  image: docker:23.0.1
+  stage: build
+  # services:
+  #   - docker:23.0.1-dind
+  script:
+    - docker buildx create --use default
+    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+    - docker buildx build .  
+      -f Dockerfile
+      --build-arg UBUNTU_VER=$UBUNTU_VER
+      -t $CI_REGISTRY/docker/ubuntu/ubuntu-$UBUNTU_VER:`date "+%Y-%m-%d"`
+      -t $CI_REGISTRY/docker/ubuntu/ubuntu-$UBUNTU_VER:latest
+      -t $CI_REGISTRY/docker/ubuntu:$UBUNTU_VER
+      -t $CI_REGISTRY/docker/ubuntu:latest
+      --platform linux/amd64,linux/arm64,linux/arm/v7
+      --push --provenance false
+