Configuring Remote Hosts

This guide covers configuring SSH access for multi-host deployments with the Rumi Controller.

Overview

The Controller uses SSH to execute commands on remote hosts and SCP to transfer files during provisioning. To deploy containers across multiple hosts, SSH access must be configured for each target host.

SSH Configuration

Authentication

The Controller supports SSH key-based authentication. The following properties configure SSH access:

Property	Description
SSH user	The username for SSH connections to target hosts
SSH key file	Path to the private key file for authentication
SSH port	The SSH port on the target host (default: 22)

These can be configured globally in controller.conf or per-container in the system's DDL model.

Key-Based Authentication

1. Generate an SSH key pair (if not already available):

   ssh-keygen -t rsa -b 4096

2. Copy the public key to each target host:

   ssh-copy-id -i ~/.ssh/id_rsa.pub user@target-host

3. Configure the Controller with the private key path and SSH user.

Passwordless Access

The Controller requires passwordless SSH access to target hosts. Ensure that:

• The SSH key is not passphrase-protected, or an SSH agent is running with the key loaded.

• The target host's authorized_keys file includes the Controller's public key.

• The target host allows key-based authentication.

Host Configuration in DDL

Each container in the DDL model specifies its target host. The Controller uses this information to determine where to provision and launch each container.

For containers running on the local machine, set the host to . to bypass SSH entirely and execute operations directly.

Firewall and Network Requirements

Ensure the following network connectivity:

From	To	Port	Purpose
Controller host	Target hosts	22 (SSH)	Provisioning and launching
Target hosts	Messaging bus	Messaging port	Container communication
Target hosts	Controller host	Discovery port	Service discovery

Troubleshooting

Connection Timeout

If provisioning fails with a connection timeout:

• Verify SSH connectivity: ssh -i <keyfile> <user>@<host>

• Check that the SSH port is correct and not blocked by a firewall.

• Increase the connection handshake timeout via nv.controller.containerconnecthandshaketimeout.

Permission Denied

If SSH authentication fails:

• Verify the SSH key file path is correct.

• Check file permissions on the private key (should be 600).

• Ensure the public key is in the target host's authorized_keys.