Troubleshooting "Failed to connect to host via ssh: Permission denied" in Ansible Ping
The Problem: You're trying to run ansible -m ping all to check the connectivity of your managed nodes, but you're met with the dreaded "Failed to connect to host via ssh: Permission denied" error. This leaves you wondering why your Ansible playbook can't connect to your hosts.
Rephrasing: Imagine you're trying to open a door, but it's locked. You have the key (your SSH credentials), but you still can't get in. That's essentially what's happening with your Ansible connection. The Ansible controller can't access your remote hosts because of a permission issue.
Understanding the Scenario
Let's break down the common scenarios that lead to this error:
1. Incorrect SSH Credentials
The most likely culprit is incorrect SSH credentials. This could involve:
- Wrong username: Make sure you're using the correct username for your remote hosts.
- Incorrect password: Double-check that you're using the right password for your SSH login.
- Incorrect private key path: If using SSH keys, verify that your private key is correctly configured in your
~/.ssh/configfile oransible.cfg.
2. SSH Configuration Issues
- SSH Port: Ensure the SSH port is open on your remote hosts and hasn't been changed from the default port (22).
- Firewall Blocking: Check if any firewall rules are blocking SSH access to your remote hosts.
- SSH Deamon: Verify that the SSH service is running on your remote hosts. You can check this with commands like
systemctl status sshdorservice sshd status(depending on your Linux distribution).
3. Permission Issues
- SSH Key Permissions: Make sure your private key file has appropriate permissions. It should be owned by the user and have read-only access for others:
chmod 600 ~/.ssh/id_rsa - SSH Access Restrictions: Verify if your SSH configuration on the remote host is set up to allow access from the Ansible controller's IP address.
4. Network Connectivity Issues
- Network Segmentation: Double-check that the Ansible controller and your remote hosts are on the same network and have proper network connectivity.
- Network Address Translation (NAT): If your remote hosts are behind a NAT device, ensure the Ansible controller can reach them.
Example Code Snippet:
ansible -m ping all
Troubleshooting Steps:
- Verify your SSH credentials: Double-check your username, password, and key paths.
- Test SSH connection manually: Use the
sshcommand to manually test your connection to the remote host. This will help pinpoint if the issue is related to SSH itself. - Check SSH configuration: Verify SSH port, firewall rules, and service status on your remote hosts.
- Examine permission settings: Check the permissions on your SSH key and verify SSH access restrictions on the remote host.
- Troubleshoot network connectivity: Ensure your Ansible controller can communicate with your remote hosts.
Additional Value:
- Using SSH Agent: To avoid constantly entering your SSH password, consider using SSH agent.
- Ansible Debug: Use the
-vvvflag to increase verbosity and gain more detailed information about the connection error. - Using the
-Tflag: This allows you to specify a different user for SSH connections. - Ansible Inventory: Make sure your inventory file is correctly configured and contains the host information.
Conclusion:
The "Failed to connect to host via ssh: Permission denied" error in Ansible can be frustrating, but with a systematic approach and careful troubleshooting, you can resolve it. Remember to check your credentials, SSH configurations, permissions, and network connectivity to identify the root cause and regain access to your remote hosts.
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