E: Package 'mysql-client' has no installation candidate in php-fpm image build using docker compose

Im fairly new to docker and so im trying to learn more about it using a laravel project, im following this tutorial: https://www.digitalocean.com/community/tutorials/how-to-set-up-laravel-nginx-and-mysql-with-docker-compose Ive adjusted the Dockerfile a bit from what the tutorial has but even the tutorial file causes the same result. ``` FROM php:7.3-fpm # Copy composer.lock and composer.json COPY composer.lock composer.json /var/www/ # Install dependencies RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - && \ apt-get update && apt-get install -y mysql-client \ RUN npm install -g npm # Clear cache RUN apt-get clean && rm -rf /var/lib/apt/lists/* # Install extensions RUN docker-php-ext-install pdo pdo_mysql # Install composer RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer # Add user for laravel application RUN groupadd -g 1000 www RUN useradd -u 1000 -ms /bin/bash -g www www # Copy existing application directory contents COPY . /var/www # Copy existing application directory permissions COPY --chown=www:www . /var/www # Change current user to www USER www # Set working directory WORKDIR /var/www # Expose port 9000 and start php-fpm server EXPOSE 9000 CMD ["php-fpm"] ``` But i keep getting the following error when i run `docker-compose up -d`: ``` E: Package 'mysql-client' has no installation candidate ERROR: Service 'app' failed to build: The command '/bin/sh -c curl -sL https://deb.nodesource.com/setup_10.x | bash - && apt-get update && apt-get install -y mysql-client nodejs build-essential vim git curl' returned a non-zero code: 100 ``` Am i missing something? I expected this to work since i am running `apt-get update` before installing `mysql-client`. Thanks.