Lab
A Cloud Guru

SELinux Learning Activity

In this lab we'll use SELinux to resolve a scenario that is common in the real world. Doing this will help to understand the tools available and where to look when troubleshooting SELinux issues. *This course is not approved or sponsored by Red Hat.*

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Path Info

Level

Intermediate

Duration

30m

Published

Apr 05, 2019

Challenge

Fix the Selinux Permissions on `/opt/website` so That They'll Survive a Relabel
- First we'll check to see what the label needs to be. Websites are normally stored in /var/www/html so we can look there to see what it should be.
- We can see that the context should be set to httpd_sys_content_t.
- The command we need to run is: semanage fcontext -a -t httpd_sys_content_t '/opt/website(/.*)?'
- This makes a change in the SELinux database.
- We then need to run restorecon /opt/website to actually make the change on the filesystem.
- This will set the directory to the correct context and protect that change from a relabel in the future.
Challenge

Deploy the Website as Instructed and Test It
- We've been instructed to deploy the website by running mv /root/index.html /opt/website/.
- We can then try a curl localhost/index.html to test our deploy.
- If we get a 403 Forbidden error, test if SELinux is the problem by running setenforce 0 and then running curl again.
- If the curl works with SELinux in permissive mode, we can set it back to enforcing with setenforce 1 and then investigate why.
Challenge

Resolve the Error When Trying to Access `/opt/website/index.html`
- ls -lZ /opt/website will show that index.html has a content type of admin_home_t which isn't what we need when serving webpages.
- We can run restorecon /opt/website/index.html to fix this error and the curl will work.

Author

A Cloud Guru

The Cloud Content team comprises subject matter experts hyper focused on services offered by the leading cloud vendors (AWS, GCP, and Azure), as well as cloud-related technologies such as Linux and DevOps. The team is thrilled to share their knowledge to help you build modern tech solutions from the ground up, secure and optimize your environments, and so much more!

What's a lab?

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.