Configuring Apache Virtual Hosts Produces Strange Notices - php

Question

I have what used to be a typical Apache 2.4 installation on an Ubuntu 16.04 LTS.
There is a /etc/apache2/sites-available/ directory where all configuration files are stored and from where one can enable sites.
Here is one of them titled localhost.conf
<VirtualHost *:80>
ServerName 127.0.0.1
ServerAlias sites.dev
DocumentRoot /var/www/sites/
<Directory />
Options FollowSymLinks
AllowOverride None
</Directory>
<Directory /var/www/sites>
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Require all granted
</Directory>
</VirtualHost>
I have enabled this site. When I navigate to sites.dev, I see the contents of that directory being listed since it does not have an index.php file. So far, so good.
I then add a info.php file to the same directory which looks like this
<?php
// Show all information, defaults to INFO_ALL
phpinfo();
?>
Now, when I navigate to sites.dev/info.php, I see a blank page.
Furthermore, when I look at the /var/log/apache2/error.log, I see entries like these
[Tue Feb 05 22:21:44.281005 2019] [mpm_prefork:notice] [pid 2149] AH00163: Apache/2.4.18 (Ubuntu) configured -- resuming normal operat$
[Tue Feb 05 22:21:44.281059 2019] [core:notice] [pid 2149] AH00094: Command line: '/usr/sbin/apache2'
[Tue Feb 05 22:24:55.006296 2019] [mpm_prefork:notice] [pid 2149] AH00169: caught SIGTERM, shutting down
[Tue Feb 05 22:24:56.064108 2019] [mpm_prefork:notice] [pid 2320] AH00163: Apache/2.4.18 (Ubuntu) configured -- resuming normal operat$
[Tue Feb 05 22:24:56.064149 2019] [core:notice] [pid 2320] AH00094: Command line: '/usr/sbin/apache2'
Could someone tell me what is happening? How can I fix this localhost and the local development environment?

Answer 1

I solved it using the following sequence of steps:
Install PHP 7 (even though it was already installed)
apt-get install php
apt-get install php-pear php7.0-dev php7.0-zip php7.0-curl php7.0-gd php7.0-mysql php7.0-mcrypt php7.0-xml libapache2-mod-php7.0
sudo a2enmod proxy_fcgi setenvif
sudo a2enconf php7.0-fpm
sudo service apache2 reload