agent debug improvements

lib/towerops/snmp/agent_discovery.ex

@@ -59,33 +59,47 @@ defmodule Towerops.Snmp.AgentDiscovery do
   @spec process_agent_discovery(DeviceSchema.t(), map()) ::
           {:ok, Discovery.Device.t()} | {:error, term()}
   def process_agent_discovery(device, oid_values) when is_map(oid_values) do
+    oid_count = map_size(oid_values)
+
     Logger.info("Processing agent discovery for #{device.name} (#{device.ip_address})",
       device_id: device.id,
-      oid_count: map_size(oid_values)
+      oid_count: oid_count
     )
 
-    # Build connection opts with Replay adapter
-    client_opts = build_replay_opts(device, oid_values)
+    # Check for empty OID map - this indicates agent couldn't collect any SNMP data
+    if oid_count == 0 do
+      Logger.error(
+        "Agent collected 0 OIDs for #{device.name} (#{device.ip_address})",
+        device_id: device.id,
+        troubleshooting:
+          "Agent couldn't collect SNMP data. Check: 1) Device reachable from agent network (ping #{device.ip_address}), 2) SNMP enabled on device, 3) Firewall allows UDP port #{device.snmp_port || 161}, 4) Community string '#{obscure_community(device)}' correct, 5) SNMP version matches device configuration"
+      )
 
-    # Run discovery using standard pipeline
-    # This will call all the same functions as direct discovery,
-    # but read from the OID map instead of making SNMP queries
-    case Discovery.discover_device_with_opts(device, client_opts) do
-      {:ok, discovered_device} ->
-        Logger.info("Agent discovery succeeded for #{device.name}",
-          device_id: device.id,
-          interfaces: length(discovered_device.interfaces || []),
-          sensors: count_sensors(discovered_device)
-        )
+      {:error, :agent_collected_no_data}
+    else
+      # Build connection opts with Replay adapter
+      client_opts = build_replay_opts(device, oid_values)
 
-        {:ok, discovered_device}
+      # Run discovery using standard pipeline
+      # This will call all the same functions as direct discovery,
+      # but read from the OID map instead of making SNMP queries
+      case Discovery.discover_device_with_opts(device, client_opts) do
+        {:ok, discovered_device} ->
+          Logger.info("Agent discovery succeeded for #{device.name}",
+            device_id: device.id,
+            interfaces: length(discovered_device.interfaces || []),
+            sensors: count_sensors(discovered_device)
+          )
 
-      {:error, reason} = error ->
-        Logger.error("Agent discovery failed for #{device.name}: #{inspect(reason)}",
-          device_id: device.id
-        )
+          {:ok, discovered_device}
 
-        error
+        {:error, reason} = error ->
+          Logger.error("Agent discovery failed for #{device.name}: #{inspect(reason)}",
+            device_id: device.id
+          )
+
+          error
+      end
     end
   end
 
@@ -116,4 +130,17 @@ defmodule Towerops.Snmp.AgentDiscovery do
       0
     end
   end
+
+  # Obscure community string for logging (show first 3 chars + ***)
+  @spec obscure_community(DeviceSchema.t()) :: String.t()
+  defp obscure_community(device) do
+    snmp_config = Devices.get_snmp_config(device)
+    community = snmp_config.community || "unknown"
+
+    if String.length(community) > 3 do
+      String.slice(community, 0..2) <> "***"
+    else
+      "***"
+    end
+  end
 end

lib/towerops/snmp/deferred_discovery.ex

@@ -173,7 +173,26 @@ defmodule Towerops.Snmp.DeferredDiscovery do
 
         if elapsed < fast_threshold, do: :fast, else: :slow
 
-      {:error, _} ->
+      {:error, reason} ->
+        # Log detailed diagnostics to help troubleshoot connectivity issues
+        ip = Keyword.get(client_opts, :ip, "unknown")
+        community = Keyword.get(client_opts, :community, "unknown")
+        version = Keyword.get(client_opts, :version, "unknown")
+        port = Keyword.get(client_opts, :port, 161)
+        adapter = Keyword.get(client_opts, :adapter, "Real SNMP")
+
+        Logger.warning(
+          "Device #{ip} categorized as unresponsive - SNMP GET failed",
+          ip: ip,
+          port: port,
+          version: version,
+          community: String.slice(community, 0..3) <> "***",
+          adapter: inspect(adapter),
+          error: inspect(reason),
+          troubleshooting:
+            "Check: 1) Device reachable (ping #{ip}), 2) SNMP enabled on device, 3) Firewall allows UDP #{port}, 4) Community string correct, 5) SNMP version matches"
+        )
+
         :unresponsive
     end
   end

lib/towerops/snmp/discovery.ex

@@ -143,10 +143,19 @@ defmodule Towerops.Snmp.Discovery do
     if device.snmp_enabled do
       Logger.info("Starting discovery with custom opts for: #{device.name}")
 
-      # Categorize device speed for adaptive timeouts
-      # Note: For Replay adapter, this will be fast since no network calls
-      device_speed = DeferredDiscovery.categorize_device_speed(client_opts)
-      timeouts = DeferredDiscovery.timeouts_for_speed(device_speed)
+      # Skip speed categorization for Replay adapter (agent-based discovery)
+      # Agent data is pre-collected, so network checks are not needed
+      adapter = Keyword.get(client_opts, :adapter)
+
+      {device_speed, timeouts} =
+        if adapter == Towerops.Snmp.Adapters.Replay do
+          Logger.debug("Using Replay adapter, skipping speed categorization")
+          {:fast, DeferredDiscovery.timeouts_for_speed(:fast)}
+        else
+          # Categorize device speed for adaptive timeouts (real SNMP)
+          speed = DeferredDiscovery.categorize_device_speed(client_opts)
+          {speed, DeferredDiscovery.timeouts_for_speed(speed)}
+        end
 
       if device_speed == :unresponsive do
         Logger.warning("Device #{device.name} is unresponsive, aborting discovery")