From 1ef9e00a0539bdc7dec84db5626942f9bb03c819 Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Thu, 4 Jun 2026 16:33:12 -0500
Subject: [PATCH] update robots.txt

---
 lib/aprsme/is/is.ex    | 56 ++++++++++++++++++++++++++++++++++++------
 priv/static/robots.txt | 29 ++++++++++++++++++++++
 2 files changed, 78 insertions(+), 7 deletions(-)

diff --git a/lib/aprsme/is/is.ex b/lib/aprsme/is/is.ex
index 7f371c5..eddc3e1 100644
--- a/lib/aprsme/is/is.ex
+++ b/lib/aprsme/is/is.ex
@@ -10,6 +10,8 @@ defmodule Aprsme.Is do
   @aprs_timeout 60 * 1000
   @keepalive_interval 20 * 1000
   @backpressure_safety_valve_timeout 30_000
+  @fallback_server "noam.aprs2.net"
+  @fallback_timeout_seconds 300
 
   defstruct [
     :server,
@@ -21,12 +23,13 @@ defmodule Aprsme.Is do
     :packet_stats,
     :login_params,
     :safety_valve_timer,
+    :failure_started_at,
     buffer: "",
     backpressure_active: false
   ]
 
   @type t :: %__MODULE__{
-          server: charlist() | String.t(),
+          server: String.t(),
           port: pos_integer(),
           socket: :ssl.sslsocket() | nil,
           timer: reference() | nil,
@@ -36,7 +39,8 @@ defmodule Aprsme.Is do
           buffer: String.t(),
           login_params: LoginParams.t(),
           backpressure_active: boolean(),
-          safety_valve_timer: reference() | nil
+          safety_valve_timer: reference() | nil,
+          failure_started_at: DateTime.t() | nil
         }
 
   def start_link(opts \\ []) do
@@ -69,7 +73,19 @@ defmodule Aprsme.Is do
     Process.sleep(Application.get_env(:aprsme, :is_init_delay_ms, 2_000))
 
     # Get startup parameters
-    server = Application.get_env(:aprsme, :aprs_is_server, ~c"dallas.aprs2.net")
+    server_raw = Application.get_env(:aprsme, :aprs_is_server, ~c"dallas.aprs2.net")
+    server = if is_list(server_raw), do: List.to_string(server_raw), else: server_raw
+
+    # If we fell back to the fallback server in a previous failure streak and
+    # the GenServer restarted (e.g. due to timeout), persist the fallback choice.
+    server =
+      if Application.get_env(:aprsme, :aprs_is_using_fallback, false) do
+        Logger.warning("APRS-IS fallback active from previous failure, connecting to #{@fallback_server}")
+        @fallback_server
+      else
+        server
+      end
+
     port = Application.get_env(:aprsme, :aprs_is_port, 14_580)
     default_filter = Application.get_env(:aprsme, :aprs_is_default_filter, "r/33/-96/100")
     aprs_user_id = Application.get_env(:aprsme, :aprs_is_login_id, "W5ISP")
@@ -91,7 +107,8 @@ defmodule Aprsme.Is do
         user_id: aprs_user_id,
         passcode: aprs_passcode,
         filter: default_filter
-      }
+      },
+      failure_started_at: nil
     }
 
     # Try to connect initially, but don't fail if it doesn't work
@@ -101,19 +118,19 @@ defmodule Aprsme.Is do
           :ok ->
             timer = create_timer(@aprs_timeout)
             keepalive_timer = create_keepalive_timer(@keepalive_interval)
-            {:ok, %{state | socket: socket, timer: timer, keepalive_timer: keepalive_timer}}
+            {:ok, reset_failure(%{state | socket: socket, timer: timer, keepalive_timer: keepalive_timer})}
 
           error ->
             Logger.warning("Failed to login to APRS-IS: #{inspect(error)}, will retry")
             :gen_tcp.close(socket)
             schedule_reconnect(5000)
-            {:ok, state}
+            {:ok, track_failure(state)}
         end
 
       error ->
         Logger.warning("Unable to establish initial connection to APRS-IS: #{inspect(error)}, will retry")
         schedule_reconnect(5000)
-        {:ok, state}
+        {:ok, track_failure(state)}
     end
   end
 
@@ -648,4 +665,29 @@ defmodule Aprsme.Is do
   defp schedule_reconnect(delay) do
     Process.send_after(self(), :reconnect, delay)
   end
+
+  # Track a connection failure. If we've been failing continuously for
+  # @fallback_timeout_seconds, switch to the fallback server until next restart.
+  defp track_failure(state) do
+    now = DateTime.utc_now()
+    failure_started_at = state.failure_started_at || now
+
+    if DateTime.diff(now, failure_started_at) >= @fallback_timeout_seconds and
+         not Application.get_env(:aprsme, :aprs_is_using_fallback, false) do
+      Logger.warning(
+        "Failed to connect to APRS-IS for #{@fallback_timeout_seconds}s, " <>
+          "falling back to #{@fallback_server}"
+      )
+
+      Application.put_env(:aprsme, :aprs_is_using_fallback, true)
+      %{state | failure_started_at: failure_started_at, server: @fallback_server}
+    else
+      %{state | failure_started_at: failure_started_at}
+    end
+  end
+
+  # Reset the failure tracking on a successful connection.
+  defp reset_failure(state) do
+    %{state | failure_started_at: nil}
+  end
 end
diff --git a/priv/static/robots.txt b/priv/static/robots.txt
index 453cf89..a92d101 100644
--- a/priv/static/robots.txt
+++ b/priv/static/robots.txt
@@ -3,6 +3,7 @@
 # To ban all spiders from the entire site uncomment the next two lines:
 
 User-agent: *
+Content-Signal: search=yes,ai-train=no
 Disallow: /info
 Disallow: /packets
 Disallow: /api/v1
@@ -10,4 +11,32 @@ Disallow: /api/v1
 User-agent: AhrefsBot
 Disallow: /
 
+User-agent: Amazonbot
+Disallow: /
+
+User-agent: Applebot-Extended
+Disallow: /
+
+User-agent: Bytespider
+Disallow: /
+
+User-agent: CCBot
+Disallow: /
+
+User-agent: ClaudeBot
+Disallow: /
+
+User-agent: CloudflareBrowserRenderingCrawler
+Disallow: /
+
+User-agent: Google-Extended
+Disallow: /
+
+User-agent: GPTBot
+Disallow: /
+
+User-agent: meta-externalagent
+Disallow: /
+
+
 Sitemap: https://aprs.me/sitemap.xml