A security context defines privilege and access control settings for a Pod or Container. Security context settings include, but are not limited to:
 Discretionary Access Control: Permission to access an object, like a file, is based on user ID (UID) and group ID (GID).
 Security Enhanced Linux (SELinux): Objects are assigned security labels.
 Running as privileged or unprivileged.
 Linux Capabilities: Give a process some privileges, but not all the privileges of the root user.

We've all been there. You do everything correct - you set your container to run
as non root, you configure your application port as a dynamic port that can be
changed at runtime, and then, when runtime comes, you run something like the
following command: docker run -e PORT=80 -p 80:80 --name my-app
registry/image:tag and you see this listen tcp :80: bind: permission denied.

The problem is simple, and so is the solution.

First, the problem is you're trying to bind to a privileged port - port 80