linuxexpert-practice-labs/labs/linux-plus/2-4-4-web-and-mail-services/README.md

Linux+ 2.4.4: Web and mail services

A name-based site with Nginx on Ubuntu, an Apache virtual host with the right SELinux label on RHEL relatives, and local mail with Postfix.

Before you start

The VM needs internet access to install packages. The lab only checks that /srv/www doesn't exist yet, and notes the time, so that only mail sent from now on counts. Leave your work in place for grading: le-lab reset removes the packages it finds you installed.

Tasks

1. Debian and Ubuntu: install Nginx and serve /srv/www/lab (with an index.html of your own) for the name lab.test on port 80, from a file in /etc/nginx/conf.d/. curl -s -H 'Host: lab.test' http://127.0.0.1/ returns your page. Break the syntax on purpose once, and read what nginx -t says before you fix it.
2. RHEL relatives: install Apache and serve /srv/www/shop (with an index.html of your own) as the virtual host shop.test on port 80, starting at boot. Keep SELinux enforcing: give /srv/www the right label with a rule that survives a relabel. curl -s -H 'Host: shop.test' http://127.0.0.1/ returns your page.
3. Install Postfix and a mail command, make sure Postfix is running, and send yourself a local mail with the subject test. Read it with mail.

Hints

• apt install nginx, a server {} block with listen, server_name and root; nginx -t, systemctl reload nginx.
• dnf install httpd, a <VirtualHost *:80> block in /etc/httpd/conf.d/, apachectl configtest; a 403 means the label is wrong. semanage fcontext -a -t httpd_sys_content_t '/srv/www(/.*)?' (package policycoreutils-python-utils), restorecon -Rv /srv/www.
• postfix with s-nail (RHEL relatives) or mailutils (Ubuntu, "Local only"); systemctl enable --now postfix; echo hi | mail -s test $USER.