Gateway: fallback routes per host, for the laptop's VPN address

scripts/renew-hosts.sh

@@ -13,12 +13,15 @@ GATEWAY_SSH="${GATEWAY_SSH:-junior.gib}"
 GATEWAY_RUNTIME="${GATEWAY_RUNTIME:-podman}"
 GATEWAY_CONTAINER="${GATEWAY_CONTAINER:-wristcode-gateway}"
 
-# label | SSH host, or "local" for the machine running this script | public T3 URL
+# label | SSH host, or "local" for the machine running this script | public T3 URLs
+# A host can list several URLs, space separated, preferred first. The gateway falls back to the
+# next one when a route does not answer, such as the laptop's VPN route when it is away from home.
 HOSTS=(
   "Desktop|local|https://t3desktop.gbrown.org"
   "Mac mini|mac.gib|https://t3mac.gbrown.org"
   "server-gib|server.gib|https://t3sr.gbrown.org"
   "LittleMan|junior.gib|https://t3jr.gbrown.org"
+  "Laptop|laptop.gib|https://t3laptop.gbrown.org https://t3laptopvpn.gbrown.org"
 )
 
 # Prints a pairing credential. Runs on the T3 host. The CLI is not on PATH in non-login shells,
@@ -36,7 +39,9 @@ done
 '
 
 renew() {
-  local label="$1" ssh_host="$2" url="$3" credential
+  local label="$1" ssh_host="$2" url alternates alternate credential alt_args=""
+  read -r url alternates <<<"$3"
+  for alternate in $alternates; do alt_args+=" --alt-url '$alternate'"; done
   if [ "$ssh_host" = "local" ]; then
     credential="$(bash -c "$MINT")"
   else
@@ -48,7 +53,7 @@ renew() {
   fi
   # The credential travels on stdin, not on a command line other processes could read.
   ssh -o BatchMode=yes "$GATEWAY_SSH" \
-    "read -r credential && $GATEWAY_RUNTIME exec $GATEWAY_CONTAINER wristcode host add '$url' \"\$credential\" --label '$label'" \
+    "read -r credential && $GATEWAY_RUNTIME exec $GATEWAY_CONTAINER wristcode host add '$url' \"\$credential\" --label '$label'$alt_args" \
     <<<"$credential"
 }