build.sh

#!/bin/bash -e

if ! docker info &>/dev/null; then
  if [ -z "$DOCKER_HOST" ] && [ "$KUBERNETES_PORT" ]; then
    export DOCKER_HOST='tcp://localhost:2375'
  fi
fi

if [[ -n "$CI_REGISTRY" && -n "$CI_REGISTRY_USER" ]]; then
  echo "Logging to GitLab Container Registry with CI credentials..."
  echo "$CI_REGISTRY_PASSWORD" | docker login -u "$CI_REGISTRY_USER" --password-stdin "$CI_REGISTRY"
fi

image_previous="$CI_APPLICATION_REPOSITORY:$CI_COMMIT_BEFORE_SHA"
image_tagged="$CI_APPLICATION_REPOSITORY:$CI_APPLICATION_TAG"
image_latest="$CI_APPLICATION_REPOSITORY:latest"

echo $image_previous
echo $image_latest
echo $image_tagged

# pull images for cache - this is required, otherwise --cache-from will not work
docker image pull "$image_previous" || \
  docker image pull "$image_latest" || \
  true

docker build \
  --cache-from "$image_previous" \
  --cache-from "$image_latest" \
  --build-arg BUILDPACK_URL="$BUILDPACK_URL" \
  --build-arg HTTP_PROXY="$HTTP_PROXY" \
  --build-arg HTTPS_PROXY="$HTTPS_PROXY" \
  --build-arg FTP_PROXY="$FTP_PROXY" \
  --build-arg NO_PROXY="$NO_PROXY" \
  --tag "$CI_APPLICATION_REPOSITORY:$CI_APPLICATION_TAG" \
  --tag "$image_latest" .

docker push "$image_tagged"
docker push "$image_latest"