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

#!/command/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 $?