Lab
A Cloud Guru

Troubleshooting SELinux Issues

In this exercise, you will troubleshoot SELinux issues preventing a service from starting, as well as functioning correctly. *This course is not approved or sponsored by Red Hat.*

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Path Info

Level

Advanced

Duration

1h 0m

Published

Apr 04, 2019

Challenge

Start Apache.
Attempt to start the service:
```
systemctl start httpd
```
View the status log:
```
systemctl status httpd -l
```
View recent SELinux errors:
```
ausearch -m avc -ts recent
```
Find the inode it's attempting to write to:
```
find / -inum &lt;inode number&gt;
```
View the SELinux context of the directory/file:
```
ls -Z /var/log/httpd
```
Restore the proper file context:
```
restorecon -Rv /var/log/httpd
```
Challenge

Resolve SELinux issues preventing viewing web content.
Attempt to view the web content:
```
curl localhost
```
View recent AVC errors:
```
ausearch -m avc -ts recent
```
Find the inode of the file/directory:
```
find / -inum &lt;inode number&gt;
```
View the context of the file/directory:
```
ls -Z /home/cloud_user/html/index.html
```
Install sealert:
```
yum -y install setroubleshoot setroubleshoot-server
```
Restart the auditd service:
```
service auditd restart
```
Use sealert for more information:
```
sealert -a /var/log/audit/audit.log
```
Lookup the httpd_read_user_content boolean:
```
getsebool httpd_read_user_content
```
Set the boolean to permit reading user content:
```
setsebool -P httpd_read_user_content=1
```
View the web content:
```
curl localhost
```

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!

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