From 825077a5b0dc0c90d93bc94ae83398c4f68d0003 Mon Sep 17 00:00:00 2001 From: Egor Kislitsyn Date: Wed, 26 Jun 2019 18:36:42 +0700 Subject: [PATCH] Add Idempotency plug --- lib/pleroma/plugs/idempotency_plug.ex | 82 +++++++++++++++++++++++++ test/plugs/idempotency_plug_test.exs | 110 ++++++++++++++++++++++++++++++++++ 2 files changed, 192 insertions(+) create mode 100644 lib/pleroma/plugs/idempotency_plug.ex create mode 100644 test/plugs/idempotency_plug_test.exs diff --git a/lib/pleroma/plugs/idempotency_plug.ex b/lib/pleroma/plugs/idempotency_plug.ex new file mode 100644 index 000000000..442573d60 --- /dev/null +++ b/lib/pleroma/plugs/idempotency_plug.ex @@ -0,0 +1,82 @@ +# Pleroma: A lightweight social networking server +# Copyright © 2017-2019 Pleroma Authors +# SPDX-License-Identifier: AGPL-3.0-only + +defmodule Pleroma.Plugs.IdempotencyPlug do + import Phoenix.Controller, only: [json: 2] + import Plug.Conn + + @behaviour Plug + + @impl true + def init(opts), do: opts + + # Sending idempotency keys in `GET` and `DELETE` requests has no effect and should be avoided, as these requests are idempotent by definition. + @impl true + def call(%{method: method} = conn, _) when method in ["POST", "PUT", "PATCH"] do + case get_req_header(conn, "idempotency-key") do + [key] -> process_request(conn, key) + _ -> conn + end + end + + def call(conn, _), do: conn + + def process_request(conn, key) do + case Cachex.get(:idempotency_cache, key) do + {:ok, nil} -> + cache_resposnse(conn, key) + + {atom, message} when atom in [:ignore, :error] -> + render_error(conn, message) + + {:ok, record} -> + send_cached(conn, key, record) + end + end + + defp cache_resposnse(conn, key) do + Plug.Conn.register_before_send(conn, fn conn -> + [request_id] = get_resp_header(conn, "x-request-id") + content_type = get_content_type(conn) + + record = {request_id, content_type, conn.status, conn.resp_body} + {:ok, _} = Cachex.put(:idempotency_cache, key, record) + + conn + |> put_resp_header("idempotency-key", key) + |> put_resp_header("x-original-request-id", request_id) + end) + end + + defp send_cached(conn, key, record) do + {request_id, content_type, status, body} = record + + conn + |> put_resp_header("idempotency-key", key) + |> put_resp_header("idempotent-replayed", "true") + |> put_resp_header("x-original-request-id", request_id) + |> put_resp_content_type(content_type) + |> send_resp(status, body) + |> halt() + end + + defp render_error(conn, message) do + conn + |> put_status(:unprocessable_entity) + |> json(%{error: message}) + |> halt() + end + + defp get_content_type(conn) do + [content_type] = get_resp_header(conn, "content-type") + + if String.contains?(content_type, ";") do + content_type + |> String.split(";") + |> hd() + else + content_type + end + end +end diff --git a/test/plugs/idempotency_plug_test.exs b/test/plugs/idempotency_plug_test.exs new file mode 100644 index 000000000..aebc463e9 --- /dev/null +++ b/test/plugs/idempotency_plug_test.exs @@ -0,0 +1,110 @@ +# Pleroma: A lightweight social networking server +# Copyright © 2017-2019 Pleroma Authors +# SPDX-License-Identifier: AGPL-3.0-only + +defmodule Pleroma.Plugs.IdempotencyPlugTest do + use ExUnit.Case, async: true + use Plug.Test + + alias Pleroma.Plugs.IdempotencyPlug + alias Plug.Conn + + test "returns result from cache" do + key = "test1" + orig_request_id = "test1" + second_request_id = "test2" + body = "testing" + status = 200 + + :post + |> conn("/cofe") + |> put_req_header("idempotency-key", key) + |> Conn.put_resp_header("x-request-id", orig_request_id) + |> Conn.put_resp_content_type("application/json") + |> IdempotencyPlug.call([]) + |> Conn.send_resp(status, body) + + conn2 = + :post + |> conn("/cofe") + |> put_req_header("idempotency-key", key) + |> Conn.put_resp_header("x-request-id", second_request_id) + |> Conn.put_resp_content_type("application/json") + |> IdempotencyPlug.call([]) + + assert_raise Conn.AlreadySentError, fn -> + Conn.send_resp(conn2, :im_a_teapot, "no cofe") + end + + assert conn2.resp_body == body + assert conn2.status == status + + assert [^second_request_id] = Conn.get_resp_header(conn2, "x-request-id") + assert [^orig_request_id] = Conn.get_resp_header(conn2, "x-original-request-id") + assert [^key] = Conn.get_resp_header(conn2, "idempotency-key") + assert ["true"] = Conn.get_resp_header(conn2, "idempotent-replayed") + assert ["application/json; charset=utf-8"] = Conn.get_resp_header(conn2, "content-type") + end + + test "pass conn downstream if the cache not found" do + key = "test2" + orig_request_id = "test3" + body = "testing" + status = 200 + + conn = + :post + |> conn("/cofe") + |> put_req_header("idempotency-key", key) + |> Conn.put_resp_header("x-request-id", orig_request_id) + |> Conn.put_resp_content_type("application/json") + |> IdempotencyPlug.call([]) + |> Conn.send_resp(status, body) + + assert conn.resp_body == body + assert conn.status == status + + assert [] = Conn.get_resp_header(conn, "idempotent-replayed") + assert [^key] = Conn.get_resp_header(conn, "idempotency-key") + end + + test "passes conn downstream if idempotency is not present in headers" do + orig_request_id = "test4" + body = "testing" + status = 200 + + conn = + :post + |> conn("/cofe") + |> Conn.put_resp_header("x-request-id", orig_request_id) + |> Conn.put_resp_content_type("application/json") + |> IdempotencyPlug.call([]) + |> Conn.send_resp(status, body) + + assert [] = Conn.get_resp_header(conn, "idempotency-key") + end + + test "doesn't work with GET/DELETE" do + key = "test3" + body = "testing" + status = 200 + + conn = + :get + |> conn("/cofe") + |> put_req_header("idempotency-key", key) + |> IdempotencyPlug.call([]) + |> Conn.send_resp(status, body) + + assert [] = Conn.get_resp_header(conn, "idempotency-key") + + conn = + :delete + |> conn("/cofe") + |> put_req_header("idempotency-key", key) + |> IdempotencyPlug.call([]) + |> Conn.send_resp(status, body) + + assert [] = Conn.get_resp_header(conn, "idempotency-key") + end +end