Switch to using ubuntu as from directive, do all intermediate steps in the dockerfile itself

Dockerfile

-FROM nimmis/apache-php7
+FROM ubuntu:16.04
+MAINTAINER Carsten Karbach (c.karbach@fz-juelich.de)
+
+# install dependencies, certificates, apache
+RUN apt-get update \
+        && apt-get install -y --no-install-recommends ca-certificates \
+        && apt-get -y dist-upgrade \
+        && apt-get autoremove -y \
+        && apt-get clean all \
+        && apt-get install -y apache2 \
+        && rm -r /var/lib/apt/lists/*
+
+# Set environment variables. 
+ENV HOME /root 
+# Define working directory. 
+WORKDIR /root
+
+# disable interactive functions 
+ENV DEBIAN_FRONTEND noninteractive 
+# Install php
+RUN apt-get update && \
+ apt-get install -y curl zip unzip php libapache2-mod-php \
+  php-fpm php-cli php-mysqlnd php-pgsql php-sqlite3 php-redis \
+  php-apcu php-intl php-imagick php-mcrypt php-json php-gd php-curl && \
+ phpenmod mcrypt && \
+ rm -rf /var/lib/apt/lists/*
+
+# Install composer
+RUN cd /tmp && curl -sS https://getcomposer.org/installer | php && mv composer.phar /usr/local/bin/composer
+
+# Setup for EventsAPI application
 RUN rm /var/www/html/index.html
 # Add EventsApi source
 ADD . /var/www/html/EventsAPI
@@ -11,3 +41,8 @@ RUN cp /var/www/html/EventsAPI/configs/000-default.conf /etc/apache2/sites-avail
 RUN a2ensite default-ssl.conf
 # Set access rights for www-data, run composer
 RUN php /var/www/html/EventsAPI/utils/install.php
+
+# Default command       
+CMD ["apachectl", "-D", "FOREGROUND"]
+
+