wordpress/rootfs/etc/cont-init.d/10-verify-wordpress

#!/usr/bin/with-contenv bash
# Designed to replace original, overcomplicated entrypoint script from official wordpress docker repository
# Why not use already available tools instead?!

# Register exit handler
trap scriptExitHandler EXIT

function scriptExitHandler() {
  LAST_EXIT_CODE=$?
  if [ "${LAST_EXIT_CODE}" = "0" ]; then
    echo "> Script finished successfully"
    exit "${LAST_EXIT_CODE}"
  fi

  echo "> Script finished with an error"
  exit "${LAST_EXIT_CODE}"
}

function reportUnhealthy() {
    echo "${1:?REASON is required}" > "/tmp/.wp-unhealthy"
}

# Main function
function main() {
  # Removes trailing zero if found
  # This is required due to inconsistencies between WodPress docker image versioning and wp-cli core download
  # If patch version is 0, it is not considered by wp-cli.
  WP_VERSION=$(echo "${WP_VERSION:?}" | sed --expression='s/.0$//g')

  echo "> Verifying 'WordPress ${WP_VERSION}' installation..."
  WP_INSTALLED_VERSION="$(wp core version)"

  set -e

  rm -f "/tmp/.wp-unhealthy"
  if [ -z "${WP_INSTALLED_VERSION}" ]; then
    echo "> ERROR! WordPress installation does not seem to be present or valid. Continuing anyway..."

    reportUnhealthy "WP_NOT_PRESENT"
    return 0
  elif [ "${WP_INSTALLED_VERSION}" != "${WP_VERSION}" ]; then
    echo "> WARNING! WordPress version mismatch"
    echo "  Expected version: ${WP_VERSION}"
    echo "  Detected version: ${WP_INSTALLED_VERSION}"
    echo "> Seems like WordPress installation got updated outside image scope"
    echo "  - This is dangerous as changes will not persist when container is recreated which might lead to inconsistencies between installation and the database."
    echo "  - You should assume that recreating the container will render the website inoperable."
    echo "  - Please make sure that you're running image: nlss/wordpress:${WP_VERSION}"
    reportUnhealthy "WP_VERSION_MISMATCH"
    return 0
  else
    echo "> Identified 'WordPress ${WP_VERSION}'"
  fi
}

main "${@}"
exit $?