Merge branch 'backport/feature-track-reverse-proxy-failures' into 'maint/1.1'

backport: Track failed proxy urls and don't request them again

See merge request pleroma/pleroma!1792

1 files changed, 26 insertions, 1 deletions

diff --git a/lib/pleroma/reverse_proxy/reverse_proxy.ex b/lib/pleroma/reverse_proxy/reverse_proxy.ex
index 03efad30a..78144cae3 100644
--- a/lib/pleroma/reverse_proxy/reverse_proxy.ex
+++ b/lib/pleroma/reverse_proxy/reverse_proxy.ex
@@ -15,6 +15,7 @@ defmodule Pleroma.ReverseProxy do
   @valid_resp_codes [200, 206, 304]
   @max_read_duration :timer.seconds(30)
   @max_body_length :infinity
+  @failed_request_ttl :timer.seconds(60)
   @methods ~w(GET HEAD)
 
   @moduledoc """
@@ -48,6 +49,8 @@ defmodule Pleroma.ReverseProxy do
   * `max_read_duration` (default `#{inspect(@max_read_duration)}` ms): the total time the connection is allowed to
   read from the remote upstream.
 
+  * `failed_request_ttl` (default `#{inspect(@failed_request_ttl)}` ms): the time the failed request is cached and cannot be retried.
+
   * `inline_content_types`:
     * `true` will not alter `content-disposition` (up to the upstream),
     * `false` will add `content-disposition: attachment` to any request,
@@ -83,6 +86,7 @@ defmodule Pleroma.ReverseProxy do
           {:keep_user_agent, boolean}
           | {:max_read_duration, :timer.time() | :infinity}
           | {:max_body_length, non_neg_integer() | :infinity}
+          | {:failed_request_ttl, :timer.time() | :infinity}
           | {:http, []}
           | {:req_headers, [{String.t(), String.t()}]}
           | {:resp_headers, [{String.t(), String.t()}]}
@@ -108,7 +112,8 @@ defmodule Pleroma.ReverseProxy do
         opts
       end
 
-    with {:ok, code, headers, client} <- request(method, url, req_headers, hackney_opts),
+    with {:ok, nil} <- Cachex.get(:failed_proxy_url_cache, url),
+         {:ok, code, headers, client} <- request(method, url, req_headers, hackney_opts),
          :ok <-
            header_length_constraint(
              headers,
@@ -116,12 +121,18 @@ defmodule Pleroma.ReverseProxy do
            ) do
       response(conn, client, url, code, headers, opts)
     else
+      {:ok, true} ->
+        conn
+        |> error_or_redirect(url, 500, "Request failed", opts)
+        |> halt()
+
       {:ok, code, headers} ->
         head_response(conn, url, code, headers, opts)
         |> halt()
 
       {:error, {:invalid_http_response, code}} ->
         Logger.error("#{__MODULE__}: request to #{inspect(url)} failed with HTTP status #{code}")
+        track_failed_url(url, code, opts)
 
         conn
         |> error_or_redirect(
@@ -134,6 +145,7 @@ defmodule Pleroma.ReverseProxy do
 
       {:error, error} ->
         Logger.error("#{__MODULE__}: request to #{inspect(url)} failed: #{inspect(error)}")
+        track_failed_url(url, error, opts)
 
         conn
         |> error_or_redirect(url, 500, "Request failed", opts)
@@ -388,4 +400,17 @@ defmodule Pleroma.ReverseProxy do
   end
 
   defp client, do: Pleroma.ReverseProxy.Client
+
+  defp track_failed_url(url, code, opts) do
+    code = to_string(code)
+
+    ttl =
+      if code in ["403", "404"] or String.starts_with?(code, "5") do
+        Keyword.get(opts, :failed_request_ttl, @failed_request_ttl)
+      else
+        nil
+      end
+
+    Cachex.put(:failed_proxy_url_cache, url, true, ttl: ttl)
+  end
 end