Build docker image with kaniko in GitLab pipeline

GitLab offers a CICD pipeline template for building docker images — Docker.gitlab-ci.yml. As shown below, it uses docker-in-docker approach. To be more specific:

• docker:latest (image) is the docker client
• docker:dind (service) is the docker daemon, dind stands for docker-in-docker.

docker-build:
  # Use the official docker image.
  image: docker:latest
  stage: build
  services:
    - docker:dind
  before_script:
    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY…