How to run cron and web application in same container?

I am new to docker. Hardly I have containerized my php application to run it in the web interface. But I have some cron to run with it. I learnt how to create separate cron image and run it from How to run a cron job inside a docker container?. But my use case is different. I need to use the php files from my php application container which seems not possible from my way. I tried creating the docker-compose.yml as follow to see if it would work

docker-compose.yml:

    version: "3"
    
    services:
        app:
          build:
            context: ./docker/php
    container_name: 'app'
    restart: 'always'
    ports:
       - "80:80"
       - "443:443"
    links:
       - db
    volumes:
       - ${DOCUMENT_ROOT-./src}:/var/www/html
       - ${PHP_INI-./docker/php/php.ini}:/usr/local/etc/php/php.ini
       - ${VHOSTS_DIR-./docker/apache2/vhosts}:/etc/apache2/sites-enabled
       - ${LOG_DIR-./docker/logs/apache2}:/var/log/apache2
    extra_hosts:
       - "test.local:127.0.0.1"
    hostname: cloudservice.local
    domainname: local
    #entrypoint: sh /var/www/html/cron.sh

As I have commented entry point here and if I do docker-compose up, everything works perfectly fine, My Dockerfile is as under

Dockerfile:

    FROM php:7.2.27-apache
    
    RUN apt-get update
    RUN apt-get install -y cron
    RUN apt-get -y update --fix-missing
    RUN apt-get upgrade -y
    
    # Install useful tools
    RUN apt-get -y install apt-utils nano wget dialog
    
    # Install important libraries
    RUN apt-get -y install --fix-missing apt-utils build-essential git curl libcurl4 libcurl4-openssl-dev zip
    
    # Composer
    RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
    
    # Install xdebug
    #RUN pecl install xdebug-2.5.0
    #RUN docker-php-ext-enable xdebug
    
    # Other PHP7 Extensions
    
    RUN apt-get -y install libsqlite3-dev libsqlite3-0 default-mysql-client
    RUN docker-php-ext-install pdo_mysql 
    RUN docker-php-ext-install pdo_sqlite
    RUN docker-php-ext-install mysqli
    
    RUN docker-php-ext-install curl
    RUN docker-php-ext-install tokenizer
    RUN docker-php-ext-install json
    
    RUN apt-get -y install zlib1g-dev
    RUN docker-php-ext-install zip
    
    RUN apt-get -y install libicu-dev
    RUN docker-php-ext-install -j$(nproc) intl
    
    RUN docker-php-ext-install mbstring
    
    RUN apt-get install -y libfreetype6-dev libjpeg62-turbo-dev libpng-dev
    RUN docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ 
    RUN docker-php-ext-install -j$(nproc) gd
    
    RUN pecl install redis-5.1.1 
        && docker-php-ext-enable redis
    
    # Enable apache modules
    RUN a2enmod rewrite headers

My cron.sh file is as under

#!/usr/bin/env bash

# Ensure the log file exists
touch /var/www/html/logs/crontab.log

# Ensure permission on the command
chmod a+x /var/www/html/cron-local/hn-shc-rapid-daily.sh

# Added a cronjob in a new crontab
echo "* * * * * bash /var/www/html/cron-local/hn-shc-rapid-daily.sh >> /var/www/html/logs/crontab.log 2>&1" > /etc/crontab

# Registering the new crontab
crontab /etc/crontab

# Starting the cron
/usr/sbin/service cron start

# Displaying logs
# Useful when executing docker-compose logs mycron
tail -f /var/www/html/logs/crontab.log

But with the entry point commented, i cannot run cron. If i don’t comment entrypoint, then cron runs, my web application doesn’t. Is there any possibility to fix this?

Thanks

Answer

At the end of the docker file i added the following code after removing

RUN a2enmod rewrite headers

    # Copy hello-cron file to the cron.d directory
    COPY hello-cron /etc/cron.d/hello-cron #just any name

    # Give execution rights on the cron job
    RUN chmod 0644 /etc/cron.d/hello-cron

    # Apply cron job
    RUN crontab /etc/cron.d/hello-cron

    # Create the log file to be able to run tail
    RUN touch /var/log/cron.log

    # Enable apache modules
    RUN a2enmod rewrite headers
    
    CMD cron && /usr/sbin/apache2ctl -D FOREGROUND

and cron.sh was changed to

    * * * * * echo "hello world" >> /var/www/html/logs/crontab.log 2>&1

This worked for me. I need not have to add entry neither on docker-compose nor on docker file, but I guess entry also would work. I don’t know if this is the right way to do. If anyone would give me more advance idea, I would be happy to give it a try. Thanks

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Answer