Linux users and SSH keys: logging in safely

You need to administer a remote Linux machine without sharing one password among everyone. SSH provides an encrypted remote connection, and a key pair can authenticate the person connecting.

The public key goes on the server account's allowed-key list. The private key stays with its owner. The Linux account and its groups decide which files and commands that person may use after login; possessing a valid key does not automatically grant administrator rights. Practice with a separate lab account and keep a working recovery login while changing access.

Try it in a lab

In a disposable VM, create a non-root account and a dedicated lab key pair. Add only the public key to authorized_keys and verify ownership and permissions. Keep a working console available while changing SSH settings.

Check your understanding

Demonstrate that the intended key works, an unrelated key fails, and ordinary commands run without root privileges. Explain where the private key belongs.

Before you start

Never copy a private key into the server account or an example repository. Test a new login before closing the existing session.

Read the official guide

Use the project documentation for version-specific commands and prerequisites. Record the versions and results of your own exercise. This page proposes a learning activity; it does not report a Kubedex test.

This is a newly written study reference at an address from the original Kubedex course outline. The original lesson was not recovered. It does not include course enrolment, progress tracking or a certificate.