Log unsupported API version when requesting device extensions (#1701)

lib/nerves_hub/audit_logs/templates.ex

@@ -1,6 +1,8 @@
 defmodule NervesHub.AuditLogs.Templates do
   alias NervesHub.AuditLogs
 
+  require Logger
+
   def audit_resolve_changed_deployment(device, reference_id) do
     description =
       if device.deployment_id do
@@ -28,4 +30,12 @@ defmodule NervesHub.AuditLogs.Templates do
 
     AuditLogs.audit_with_ref!(device, device, description, reference_id)
   end
+
+  def audit_unsupported_api_version(device) do
+    description =
+      "device #{device.identifier} could not get extensions: Unsupported API version."
+
+    AuditLogs.audit!(device, device, description)
+    Logger.info("[DeviceChannel] #{description}")
+  end
 end

lib/nerves_hub_web/channels/device_channel.ex

@@ -63,7 +63,8 @@ defmodule NervesHubWeb.DeviceChannel do
     # Earlier versions of nerves_hub_link don't have a fallback for unknown messages,
     # so check version before requesting extensions
     if is_safe_to_request_extensions?(socket.assigns.device_api_version),
-      do: push(socket, "extensions:get", %{})
+      do: push(socket, "extensions:get", %{}),
+      else: Templates.audit_unsupported_api_version(device)
 
     {:noreply, socket}
   end