Merge branch 'pleroma-http-stream' into 'develop'

Pleroma.HTTP: support streaming response bodies

See merge request pleroma/pleroma!4239

changelog.d/rich-media-no-heads.change

@@ -0,0 +1 @@
+Rich Media preview fetching will skip making an HTTP HEAD request to check a URL for allowed content type and length if the Tesla adapter is Gun or Finch

lib/pleroma/http/adapter_helper.ex

@@ -52,6 +52,7 @@ defmodule Pleroma.HTTP.AdapterHelper do
     case adapter() do
       Tesla.Adapter.Gun -> AdapterHelper.Gun
       Tesla.Adapter.Hackney -> AdapterHelper.Hackney
+      {Tesla.Adapter.Finch, _} -> AdapterHelper.Finch
       _ -> AdapterHelper.Default
     end
   end
@@ -118,4 +119,13 @@ defmodule Pleroma.HTTP.AdapterHelper do
         host_charlist
     end
   end
+
+  @spec can_stream? :: bool()
+  def can_stream? do
+    case Application.get_env(:tesla, :adapter) do
+      Tesla.Adapter.Gun -> true
+      {Tesla.Adapter.Finch, _} -> true
+      _ -> false
+    end
+  end
 end

lib/pleroma/http/adapter_helper/finch.ex

@@ -0,0 +1,33 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.HTTP.AdapterHelper.Finch do
+  @behaviour Pleroma.HTTP.AdapterHelper
+
+  alias Pleroma.Config
+  alias Pleroma.HTTP.AdapterHelper
+
+  @spec options(keyword(), URI.t()) :: keyword()
+  def options(incoming_opts \\ [], %URI{} = _uri) do
+    proxy =
+      [:http, :proxy_url]
+      |> Config.get()
+      |> AdapterHelper.format_proxy()
+
+    config_opts = Config.get([:http, :adapter], [])
+
+    config_opts
+    |> Keyword.merge(incoming_opts)
+    |> AdapterHelper.maybe_add_proxy(proxy)
+    |> maybe_stream()
+  end
+
+  # Finch uses [response: :stream]
+  defp maybe_stream(opts) do
+    case Keyword.pop(opts, :stream, nil) do
+      {true, opts} -> Keyword.put(opts, :response, :stream)
+      {_, opts} -> opts
+    end
+  end
+end

lib/pleroma/http/adapter_helper/gun.ex

@@ -32,6 +32,7 @@ defmodule Pleroma.HTTP.AdapterHelper.Gun do
     |> AdapterHelper.maybe_add_proxy(proxy)
     |> Keyword.merge(incoming_opts)
     |> put_timeout()
+    |> maybe_stream()
   end
 
   defp add_scheme_opts(opts, %{scheme: "http"}), do: opts
@@ -47,6 +48,14 @@ defmodule Pleroma.HTTP.AdapterHelper.Gun do
     Keyword.put(opts, :timeout, recv_timeout)
   end
 
+  # Gun uses [body_as: :stream]
+  defp maybe_stream(opts) do
+    case Keyword.pop(opts, :stream, nil) do
+      {true, opts} -> Keyword.put(opts, :body_as, :stream)
+      {_, opts} -> opts
+    end
+  end
+
   @spec pool_timeout(pool()) :: non_neg_integer()
   def pool_timeout(pool) do
     default = Config.get([:pools, :default, :recv_timeout], 5_000)

lib/pleroma/web/rich_media/helpers.ex

@@ -11,16 +11,39 @@ defmodule Pleroma.Web.RichMedia.Helpers do
 
   @spec rich_media_get(String.t()) :: {:ok, String.t()} | get_errors()
   def rich_media_get(url) do
-    headers = [{"user-agent", Pleroma.Application.user_agent() <> "; Bot"}]
+    case Pleroma.HTTP.AdapterHelper.can_stream?() do
+      true -> stream(url)
+      false -> head_first(url)
+    end
+    |> handle_result(url)
+  end
 
+  defp stream(url) do
+    with {_, {:ok, %Tesla.Env{status: 200, body: stream_body, headers: headers}}} <-
+           {:get, Pleroma.HTTP.get(url, req_headers(), http_options())},
+         {_, :ok} <- {:content_type, check_content_type(headers)},
+         {_, :ok} <- {:content_length, check_content_length(headers)},
+         {:read_stream, {:ok, body}} <- {:read_stream, read_stream(stream_body)} do
+      {:ok, body}
+    end
+  end
+
+  defp head_first(url) do
     with {_, {:ok, %Tesla.Env{status: 200, headers: headers}}} <-
-           {:head, Pleroma.HTTP.head(url, headers, http_options())},
+           {:head, Pleroma.HTTP.head(url, req_headers(), http_options())},
          {_, :ok} <- {:content_type, check_content_type(headers)},
          {_, :ok} <- {:content_length, check_content_length(headers)},
          {_, {:ok, %Tesla.Env{status: 200, body: body}}} <-
-           {:get, Pleroma.HTTP.get(url, headers, http_options())} do
+           {:get, Pleroma.HTTP.get(url, req_headers(), http_options())} do
       {:ok, body}
-    else
+    end
+  end
+
+  defp handle_result(result, url) do
+    case result do
+      {:ok, body} ->
+        {:ok, body}
+
       {:head, _} ->
         Logger.debug("Rich media error for #{url}: HTTP HEAD failed")
         {:error, :head}
@@ -29,8 +52,12 @@ defmodule Pleroma.Web.RichMedia.Helpers do
         Logger.debug("Rich media error for #{url}: content-type is #{type}")
         {:error, :content_type}
 
-      {:content_length, {_, length}} ->
+      {:content_length, :error} ->
-        Logger.debug("Rich media error for #{url}: content-length is #{length}")
+        Logger.debug("Rich media error for #{url}: content-length exceeded")
+        {:error, :body_too_large}
+
+      {:read_stream, :error} ->
+        Logger.debug("Rich media error for #{url}: content-length exceeded")
         {:error, :body_too_large}
 
       {:get, _} ->
@@ -59,7 +86,7 @@ defmodule Pleroma.Web.RichMedia.Helpers do
       {_, maybe_content_length} ->
         case Integer.parse(maybe_content_length) do
           {content_length, ""} when content_length <= max_body -> :ok
-          {_, ""} -> {:error, maybe_content_length}
+          {_, ""} -> :error
           _ -> :ok
         end
 
@@ -68,13 +95,37 @@ defmodule Pleroma.Web.RichMedia.Helpers do
     end
   end
 
-  defp http_options do
+  defp read_stream(stream) do
-    timeout = Config.get!([:rich_media, :timeout])
+    max_body = Keyword.get(http_options(), :max_body)
 
+    try do
+      result =
+        Stream.transform(stream, 0, fn chunk, total_bytes ->
+          new_total = total_bytes + byte_size(chunk)
+
+          if new_total > max_body do
+            raise("Exceeds max body limit of #{max_body}")
+          else
+            {[chunk], new_total}
+          end
+        end)
+        |> Enum.into(<<>>)
+
+      {:ok, result}
+    rescue
+      _ -> :error
+    end
+  end
+
+  defp http_options do
     [
       pool: :rich_media,
       max_body: Config.get([:rich_media, :max_body], 5_000_000),
-      tesla_middleware: [{Tesla.Middleware.Timeout, timeout: timeout}]
+      stream: true
     ]
   end
+
+  defp req_headers do
+    [{"user-agent", Pleroma.Application.user_agent() <> "; Bot"}]
+  end
 end