From 667fde17d711650c80217a358fd75b5d92b13d59 Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Tue, 27 Jan 2026 14:49:06 -0600
Subject: [PATCH] discovery deduplication

---
 lib/towerops/workers/discovery_worker.ex | 48 ++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 4 deletions(-)

diff --git a/lib/towerops/workers/discovery_worker.ex b/lib/towerops/workers/discovery_worker.ex
index 48f891f5..09a381d9 100644
--- a/lib/towerops/workers/discovery_worker.ex
+++ b/lib/towerops/workers/discovery_worker.ex
@@ -16,7 +16,9 @@ defmodule Towerops.Workers.DiscoveryWorker do
   If no agent is assigned or the agent is offline, discovery falls back to direct
   SNMP operations from the Phoenix cluster.
   """
-  use Oban.Worker, queue: :discovery
+  use Oban.Worker,
+    queue: :discovery,
+    unique: [period: 60, states: [:available, :scheduled, :executing]]
 
   alias Towerops.Agents
   alias Towerops.Devices
@@ -94,11 +96,49 @@ defmodule Towerops.Workers.DiscoveryWorker do
 
   @doc """
   Enqueues a discovery job for a device.
+
+  Uses Oban unique constraint to prevent duplicate jobs within 60 seconds.
   """
   def enqueue(device_id) do
-    %{device_id: device_id}
-    |> new()
-    |> Oban.insert()
+    # Log who's enqueueing this to track down runaway triggers
+    caller_module =
+      self()
+      |> Process.info(:current_stacktrace)
+      |> elem(1)
+      |> Enum.at(1)
+      |> elem(0)
+
+    result =
+      %{device_id: device_id}
+      |> new()
+      |> Oban.insert()
+
+    case result do
+      {:ok, %Oban.Job{conflict?: true}} ->
+        Logger.debug(
+          "Discovery job already enqueued for device, skipping duplicate",
+          device_id: device_id,
+          caller: caller_module
+        )
+
+      {:ok, _job} ->
+        Logger.debug(
+          "Discovery job enqueued for device",
+          device_id: device_id,
+          caller: caller_module
+        )
+
+      {:error, _} = error ->
+        Logger.warning(
+          "Failed to enqueue discovery job",
+          device_id: device_id,
+          caller: caller_module
+        )
+
+        error
+    end
+
+    result
   end
 
   # Private helpers