refactor(upload): make Exiftool filters deprecated aliases of Exif filters

Old configs keep working and now also strip GPS from WebP and HEIC.
The deprecation warning names the replacement for each old filter, and
exiftool is no longer a startup requirement.

lib/pleroma/application_requirements.ex

@@ -168,8 +168,6 @@ defmodule Pleroma.ApplicationRequirements do
 
   defp check_system_commands!(:ok) do
     filter_commands_statuses = [
-      check_filter(Pleroma.Upload.Filter.Exiftool.StripLocation, "exiftool"),
-      check_filter(Pleroma.Upload.Filter.Exiftool.ReadDescription, "exiftool"),
       check_filter(Pleroma.Upload.Filter.Mogrify, "mogrify"),
       check_filter(Pleroma.Upload.Filter.Mogrifun, "mogrify"),
       check_filter(Pleroma.Upload.Filter.AnalyzeMetadata, "ffprobe")

lib/pleroma/config/deprecation_warnings.ex

@@ -22,40 +22,44 @@ defmodule Pleroma.Config.DeprecationWarnings do
 
   @logger_formatter_config_knobs [:colors, :format, :metadata, :truncate, :utc_log]
 
+  @exiftool_filter_replacements %{
+    Pleroma.Upload.Filter.Exiftool => Pleroma.Upload.Filter.Exif.StripLocation,
+    Pleroma.Upload.Filter.Exiftool.StripLocation => Pleroma.Upload.Filter.Exif.StripLocation,
+    Pleroma.Upload.Filter.Exiftool.ReadDescription => Pleroma.Upload.Filter.Exif.ReadDescription
+  }
+
   def check_exiftool_filter do
     filters = Config.get([Pleroma.Upload]) |> Keyword.get(:filters, [])
 
-    if Pleroma.Upload.Filter.Exiftool in filters do
-      Logger.warning("""
-      !!!DEPRECATION WARNING!!!
-      Your config is using Exiftool as a filter instead of Exiftool.StripLocation. This should work for now, but you are advised to change to the new configuration to prevent possible issues later:
+    deprecated_filters =
+      filters
+      |> Enum.filter(&Map.has_key?(@exiftool_filter_replacements, &1))
+      |> Enum.uniq()
 
-      ```
-      config :pleroma, Pleroma.Upload,
-        filters: [Pleroma.Upload.Filter.Exiftool]
-      ```
+    case deprecated_filters do
+      [] ->
+        :ok
 
-      Is now
+      deprecated_filters ->
+        replacements =
+          Enum.map_join(deprecated_filters, fn filter ->
+            "\n* `#{inspect(filter)}` is now `#{inspect(@exiftool_filter_replacements[filter])}`"
+          end)
 
+        Logger.warning("""
+        !!!DEPRECATION WARNING!!!
+        Your config is using Exiftool upload filters. Pleroma no longer needs exiftool, the filters were replaced by built-in ones. The old names should work for now, but you are advised to change to the new configuration to prevent possible issues later:
+        #{replacements}
+        """)
 
-      ```
-      config :pleroma, Pleroma.Upload,
-        filters: [Pleroma.Upload.Filter.Exiftool.StripLocation]
-      ```
-      """)
+        new_config =
+          filters
+          |> Enum.map(&Map.get(@exiftool_filter_replacements, &1, &1))
+          |> Enum.uniq()
 
-      new_config =
-        filters
-        |> Enum.map(fn
-          Pleroma.Upload.Filter.Exiftool -> Pleroma.Upload.Filter.Exiftool.StripLocation
-          filter -> filter
-        end)
+        Config.put([Pleroma.Upload, :filters], new_config)
 
-      Config.put([Pleroma.Upload, :filters], new_config)
-
-      :error
-    else
-      :ok
+        :error
     end
   end
 

lib/pleroma/upload/filter/exiftool.ex

@@ -0,0 +1,14 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2026 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Upload.Filter.Exiftool do
+  @moduledoc """
+  Deprecated: use `Pleroma.Upload.Filter.Exif.StripLocation`. This module delegates to it.
+  """
+
+  @behaviour Pleroma.Upload.Filter
+
+  @impl true
+  defdelegate filter(upload), to: Pleroma.Upload.Filter.Exif.StripLocation
+end

lib/pleroma/upload/filter/exiftool/read_description.ex

@@ -4,51 +4,11 @@
 
 defmodule Pleroma.Upload.Filter.Exiftool.ReadDescription do
   @moduledoc """
-  Gets a valid description from the related EXIF tags and provides them in the response if no description is provided yet.
-  It will first check ImageDescription, when that doesn't probide a valid description, it will check iptc:Caption-Abstract.
-  A valid description means the fields are filled in and not too long (see `:instance, :description_limit`).
+  Deprecated: use `Pleroma.Upload.Filter.Exif.ReadDescription`. This module delegates to it.
   """
+
   @behaviour Pleroma.Upload.Filter
 
-  def filter(%Pleroma.Upload{description: description})
-      when is_binary(description),
-      do: {:ok, :noop}
-
-  def filter(%Pleroma.Upload{tempfile: file} = upload),
-    do: {:ok, :filtered, upload |> Map.put(:description, read_description_from_exif_data(file))}
-
-  def filter(_, _), do: {:ok, :noop}
-
-  defp read_description_from_exif_data(file) do
-    nil
-    |> read_when_empty(file, "-ImageDescription")
-    |> read_when_empty(file, "-iptc:Caption-Abstract")
-  end
-
-  defp read_when_empty(current_description, _, _) when is_binary(current_description),
-    do: current_description
-
-  defp read_when_empty(_, file, tag) do
-    if File.exists?(file) do
-      try do
-        {tag_content, 0} =
-          System.cmd("exiftool", ["-m", "-b", "-s3", tag, file],
-            stderr_to_stdout: false,
-            parallelism: true
-          )
-
-        tag_content = String.trim(tag_content)
-
-        if tag_content != "" and
-             String.length(tag_content) <=
-               Pleroma.Config.get([:instance, :description_limit]),
-           do: tag_content,
-           else: nil
-      rescue
-        _ in ErlangError -> nil
-      end
-    else
-      nil
-    end
-  end
+  @impl true
+  defdelegate filter(upload), to: Pleroma.Upload.Filter.Exif.ReadDescription
 end

lib/pleroma/upload/filter/exiftool/strip_location.ex

@@ -4,30 +4,11 @@
 
 defmodule Pleroma.Upload.Filter.Exiftool.StripLocation do
   @moduledoc """
-  Strips GPS related EXIF tags and overwrites the file in place.
-  Also strips or replaces filesystem metadata e.g., timestamps.
+  Deprecated: use `Pleroma.Upload.Filter.Exif.StripLocation`. This module delegates to it.
   """
+
   @behaviour Pleroma.Upload.Filter
 
-  # Formats not compatible with exiftool at this time
-  def filter(%Pleroma.Upload{content_type: "image/heic"}), do: {:ok, :noop}
-  def filter(%Pleroma.Upload{content_type: "image/webp"}), do: {:ok, :noop}
-  def filter(%Pleroma.Upload{content_type: "image/svg" <> _}), do: {:ok, :noop}
-
-  def filter(%Pleroma.Upload{tempfile: file, content_type: "image" <> _}) do
-    try do
-      case System.cmd("exiftool", ["-m", "-overwrite_original", "-gps:all=", "-png:all=", file],
-             stderr_to_stdout: true,
-             parallelism: true
-           ) do
-        {_response, 0} -> {:ok, :filtered}
-        {error, _} -> {:error, error}
-      end
-    rescue
-      e in ErlangError ->
-        {:error, "#{__MODULE__}: #{inspect(e)}"}
-    end
-  end
-
-  def filter(_), do: {:ok, :noop}
+  @impl true
+  defdelegate filter(upload), to: Pleroma.Upload.Filter.Exif.StripLocation
 end