SSH Keys & Passwordless Login
Set up key-based auth so Ansible can connect.
SSH Keys & Passwordless Login is a free Ansible Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Ansible Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Ansible Speaks SSH
Ansible connects to managed nodes over plain SSH. If you can SSH into a server, Ansible can almost certainly manage it.
Why Passwordless Matters
Typing a password for every host does not scale. SSH keys let Ansible log in to hundreds of servers with zero prompts.
A Key Pair
An SSH key is a pair: a private key you keep secret and a public key you share. The public one goes onto each server.
Generate Your Key
Create a key pair with ssh-keygen. The ed25519 type is modern, fast, and secure for connecting to your nodes.
ssh-keygen -t ed25519 -C "ansible"Two Files Appear
You now have id_ed25519 (private, guard it) and id_ed25519.pub (public, shareable). Never copy the private key onto servers.
Copy the Public Key
Push your public key to a server with ssh-copy-id. It appends the key to that host's authorized_keys file for you.
ssh-copy-id user@web1.example.comTest the Login
Now SSH to the host. If it logs in with no password prompt, key-based auth works and Ansible will too.
ssh user@web1.example.comThe remote_user
Ansible connects as a specific remote_user. Make sure that user exists on the node and has your public key authorized.
The ssh-agent
Protected your key with a passphrase? Run ssh-agent and ssh-add once so Ansible reuses the unlocked key all session.
ssh-add ~/.ssh/id_ed25519Per-Host Settings
Your ~/.ssh/config can set the user, port, and key per host. Ansible respects it, keeping inventories clean.
Keys Beat Passwords
Key-based auth is both safer and faster than passwords. Once set up, Ansible flows across your whole fleet silently. 🔑
Quick Check
Test your SSH understanding.
Recap
You generate an SSH key pair, push the public key with ssh-copy-id, and confirm a passwordless login. Now Ansible can reach every node hands-free. 🎉
Frequently asked questions
Is the “SSH Keys & Passwordless Login” lesson free?
Yes — the full text of “SSH Keys & Passwordless Login” is free to read here on the web, and the Ansible Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Ansible Academy course, upgrade to CoddyKit PRO.
What will I learn in “SSH Keys & Passwordless Login”?
Set up key-based auth so Ansible can connect. You practise Ansible Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Ansible Academy?
No prior experience is required. Ansible Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “SSH Keys & Passwordless Login” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Ansible Academy lesson?
Yes. Every Ansible Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Installing the Ansible Control Node
- SSH Keys & Passwordless Login
- Your ansible.cfg: Sensible Defaults
- Ping a Host with the ping Module