Simplicity is a form of art...

Location view of infrastructure

In this last post on the infrastructure domain, I cover the fifth and final viewpoint that is important for an infrastructure domain representation, and that is the location view. As mentioned in previous posts, the viewpoints I think are most representative of the infrastructure domain are:

• process view
• service view
• component view
• zoning view
• location view

Like with the component view, the location view is a layered approach. While I initially wanted to call it the network view, "location" might be a broader term that matches the content better. Still, it's not a perfect name, but the name is less important than the content, not?

Filtering network access per application

Iptables (and the successor nftables) is a powerful packet filtering system in the Linux kernel, able to create advanced firewall capabilities. One of the features that it cannot provide is per-application filtering. Together with SELinux however, it is possible to implement this on a per domain basis.

SELinux does not know applications, but it knows domains. If we ensure that each application runs in its own domain, then we can leverage the firewall capabilities with SELinux to only allow those domains access that we need.