scripts: add ssh_guest.sh - reliable SSH into the running vGPU guest

Password auth with key auth disabled outright: the host's id_rsa is
passphrase-protected and a stale copy of its public key in the guest's
authorized_keys made plain ssh hang on the passphrase prompt (the
reported 'sshpass hangs'). Wrapper defaults to 127.0.0.1:2222
ubuntu/ubuntu, overridable via VGPU_GUEST_*.

1 files changed, 34 insertions, 0 deletions

diff --git a/scripts/ssh_guest.sh b/scripts/ssh_guest.sh
new file mode 100755
index 0000000..b49a992
--- /dev/null
+++ b/scripts/ssh_guest.sh
@@ -0,0 +1,34 @@
+#!/bin/bash
+# ssh_guest.sh - SSH into the running vGPU guest.
+#
+# Usage:
+#   scripts/ssh_guest.sh                 # interactive shell
+#   scripts/ssh_guest.sh "nvidia-smi -L" # run one command
+#
+# Why the explicit options: the host's ~/.ssh/id_rsa is passphrase-protected
+# and the guest image once carried its public key in authorized_keys; ssh
+# offered the key, the guest accepted it and the session hung on the
+# passphrase prompt (sshpass only answers password prompts). The stale key
+# was removed from the guest; this wrapper also disables key auth outright so
+# the session can never hang that way again. Password auth is used.
+#
+# Overridable: VGPU_GUEST_HOST, VGPU_GUEST_PORT, VGPU_GUEST_USER,
+# VGPU_GUEST_PASS (defaults 127.0.0.1:2222 ubuntu/ubuntu).
+set -u
+HOST="${VGPU_GUEST_HOST:-127.0.0.1}"
+PORT="${VGPU_GUEST_PORT:-2222}"
+USER="${VGPU_GUEST_USER:-ubuntu}"
+PASS="${VGPU_GUEST_PASS:-ubuntu}"
+
+command -v sshpass >/dev/null || { echo "sshpass not installed" >&2; exit 1; }
+
+exec sshpass -p "$PASS" ssh \
+	-p "$PORT" \
+	-o StrictHostKeyChecking=no \
+	-o UserKnownHostsFile=/dev/null \
+	-o PubkeyAuthentication=no \
+	-o PreferredAuthentications=password \
+	-o ConnectTimeout=15 \
+	-o ServerAliveInterval=15 \
+	-o ServerAliveCountMax=4 \
+	"$USER@$HOST" "$@"