entrypoint.sh

#!/bin/sh

DOCKER_TOKEN=$1
DOCKER_IMAGE_NAME=$2
DOCKER_IMAGE_TAG=$3
EXTRACT_TAG_FROM_GIT_REF=$4
DOCKERFILE=$5
BUILD_CONTEXT=$6
PULL_IMAGE=$7
DOCKER_IMAGE_TAGS=$8
DOCKER_IMAGE_PLATFORM=$9
CUSTOM_DOCKER_BUILD_ARGS=${10}

if [ "$(echo ${EXTRACT_TAG_FROM_GIT_REF})" == 'true' ]; then
  DOCKER_IMAGE_TAG=$(echo ${GITHUB_REF} | sed -e "s/refs\/tags\///g")
fi

DOCKER_IMAGE_NAME=$(echo ghcr.io/${GITHUB_REPOSITORY}/${DOCKER_IMAGE_NAME} | tr '[:upper:]' '[:lower:]')
DOCKER_IMAGE_NAME_WITH_TAG=$(echo ${DOCKER_IMAGE_NAME}:${DOCKER_IMAGE_TAG} | tr '[:upper:]' '[:lower:]')

docker buildx create --use # Creating builder instance to support cross-platform builds

docker login -u publisher -p ${DOCKER_TOKEN} ghcr.io

if [ "$(echo ${PULL_IMAGE})" == 'true' ]; then
  if [ "$(echo ${DOCKER_IMAGE_PLATFORM})" != '' ]; then
    docker pull ${DOCKER_IMAGE_NAME_WITH_TAG} --platform ${DOCKER_IMAGE_PLATFORM} || docker pull ${DOCKER_IMAGE_NAME} --platform ${DOCKER_IMAGE_PLATFORM} || true
  else
    docker pull  ${DOCKER_IMAGE_NAME_WITH_TAG} || docker pull ${DOCKER_IMAGE_NAME} || true
  fi
fi

set -- -t ${DOCKER_IMAGE_NAME_WITH_TAG}

if [ "$(echo ${DOCKERFILE})" != 'Dockerfile' ]; then
  set -- $(echo ${@}) -f ${DOCKERFILE}
fi

if [ "$(echo ${DOCKER_IMAGE_PLATFORM})" != '' ]; then
  set -- $(echo ${@}) --platform ${DOCKER_IMAGE_PLATFORM}
fi

if [ "$(echo ${CUSTOM_DOCKER_BUILD_ARGS})" != '' ]; then
  set -- ${@} ${CUSTOM_DOCKER_BUILD_ARGS}
fi

set -- ${@} ${BUILD_CONTEXT}

for tag in ${DOCKER_IMAGE_TAGS}
do
    DOCKER_IMAGE_NAME_WITH_TAG=$(echo ${DOCKER_IMAGE_NAME}:${tag} | tr '[:upper:]' '[:lower:]')
    set -- -t ${DOCKER_IMAGE_NAME_WITH_TAG} ${@}
done

docker buildx build --push ${@}