Could not install cron on php-fpm container

I want to run a cron to excute laravel schedule on an container.
I’m using digitalocean.com/php with an Dockerfile like this:

FROM php:7.2-fpm

# Copy composer.lock and composer.json
COPY composer.lock composer.json /var/www/

# Set working directory
WORKDIR /var/www

# Install dependencies
RUN apt-get update && apt-get install -y 
    cron 
    build-essential 
    mariadb-client 
    libpng-dev 
    libjpeg62-turbo-dev 
    libfreetype6-dev 
    locales 
    zip 
    jpegoptim optipng pngquant gifsicle 
    vim 
    unzip 
    git 
    curl

# Clear cache
RUN apt-get clean && rm -rf /var/lib/apt/lists/*

# Install extensions
RUN docker-php-ext-install pdo_mysql mbstring zip exif pcntl
RUN docker-php-ext-configure gd --with-gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ --with-png-dir=/usr/include/
RUN docker-php-ext-install gd

# 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

# Expose port 9000 and start php-fpm server
EXPOSE 9000
CMD ["php-fpm"]

I added cron on install dependencies path but seemly, it was not installed.

docker exec -it 378e8a01b32b bash
$ cron
bash: cron: command not found

I checked log at /var/log and /var/spool but it didn’t show cron log.

/var/log$ ls
alternatives.log  apt  btmp  dpkg.log  faillog  lastlog  wtmp

/var/spool$ ls
mail

Source: StackOverflow