setup-spoke.sh: add option to choose existing key from ~/.ssh/ in SSH key setup menu

spoke/setup-spoke.sh

@@ -184,9 +184,10 @@ info "Hostname set to: $SPOKE_NAME"
 header "SSH Key Setup"
 echo "How would you like to handle the SSH key for the tunnel to $HUB_HOST?"
 echo "  1) Generate a new key automatically"
-echo "  2) Use an existing key (paste the private key)"
+echo "  2) Choose an existing key from $SSH_DIR"
+echo "  3) Paste a private key manually"
 echo ""
-read -rp "Choose [1/2]: " KEY_CHOICE
+read -rp "Choose [1/2/3]: " KEY_CHOICE
 
 case "$KEY_CHOICE" in
 1)
@@ -217,6 +218,34 @@ case "$KEY_CHOICE" in
     read -rp "Press ENTER once the key has been added to ${HUB_HOST}..."
     ;;
 2)
+    mkdir -p "$SSH_DIR"
+    chown "$SPOKE_USER":"$SPOKE_USER" "$SSH_DIR"
+    chmod 700 "$SSH_DIR"
+
+    AVAILABLE_KEYS=()
+    while IFS= read -r keyfile; do
+        AVAILABLE_KEYS+=("$keyfile")
+    done < <(find "$SSH_DIR" -maxdepth 1 -type f ! -name "*.pub" ! -name "known_hosts" ! -name "authorized_keys" ! -name "config" | sort)
+
+    if [ ${#AVAILABLE_KEYS[@]} -eq 0 ]; then
+        die "No private keys found in $SSH_DIR."
+    fi
+
+    echo "Available keys:"
+    for i in "${!AVAILABLE_KEYS[@]}"; do
+        echo "  $i) ${AVAILABLE_KEYS[$i]}"
+    done
+    echo ""
+    read -rp "Choose key [0]: " KEY_IDX
+    KEY_IDX="${KEY_IDX:-0}"
+    [[ "$KEY_IDX" =~ ^[0-9]+$ ]] && [ "$KEY_IDX" -lt "${#AVAILABLE_KEYS[@]}" ] || die "Invalid choice."
+    KEY_PATH="${AVAILABLE_KEYS[$KEY_IDX]}"
+    KEY_NAME="$(basename "$KEY_PATH")"
+    info "Using existing key: $KEY_PATH"
+    echo ""
+    read -rp "Press ENTER once the public key has been added to ${HUB_HOST} authorized_keys..."
+    ;;
+3)
     read -rp "Enter a name for the key file [hubkey]: " KEY_NAME
     KEY_NAME="${KEY_NAME:-hubkey}"
     KEY_PATH="$SSH_DIR/$KEY_NAME"