SSH Key & Diagnostics (/setup-ssh, /diag)

Deploy the SSH Key & Verify the Connection

/setup-ssh — the plugin key

Fleet Manager uses its own dedicated SSH key: ~/.ssh/fleet-manager_ed25519 (Ed25519). /setup-ssh creates it when needed and is idempotent — re-running it on an already configured server is a no-op.

If the key is not yet on the server, the command shows you a line to copy, which you type verbatim — including the leading ! — into Claude Code:

! ssh-copy-id -p <port> -i ~/.ssh/fleet-manager_ed25519.pub <user>@<host>

The ! is a Claude Code prefix and essential: it opens an interactive terminal for password entry. Without !, ssh-copy-id would hang.

Host key on first connection

Fleet Manager does not disable host-key checking — that is deliberately the secure choice. Because all connections run with BatchMode=yes (no interactive prompts), the first connection to an unknown host fails on purpose instead of blindly trusting the key. This prevents a silent man-in-the-middle.

Register the host key once, after reviewing the fingerprint:

ssh-keyscan -p <port> <host> >> ~/.ssh/known_hosts

Alternatively, connect once manually (ssh -p <port> <user>@<host>) and accept the key.

/diag — check connectivity & health

After deploying the key, /diag [server] checks the essentials:

• SSH reachability
• passwordless sudo (for privileged actions)
• Docker availability — automatically detects the right docker_cmd
• disk and load snapshot

Each check returns PASS, WARN or FAIL. The results are stored in the server profile.