Remove FedSockets

Current FedSocket implementation has a bunch of problems. It doesn't
have proper error handling (in case of an error the server just doesn't
respond until the connection is closed, while the client doesn't match
any error messages and just assumes there has been an error after 15s)
and the code is full of bad descisions (see: fetch registry which uses
uuids for no reason and waits for a response by recursively querying a
 ets table until the value changes, or double JSON encoding).

Sometime ago I almost completed rewriting fedsockets from scrach to
adress these issues. However, while doing so, I realized that fedsockets
 are just too overkill for what they were trying to accomplish, which is
 reduce the overhead of federation by not signing every message.
This could be done without reimplementing failure states and endpoint
 logic we already have with HTTP by, for example, using TLS cert auth,
or switching to a more performant signature algorithm. I opened
https://git.pleroma.social/pleroma/pleroma/-/issues/2262 for further
discussion on alternatives to fedsockets.

From discussions I had with other Pleroma developers it seems like they
 would approve the descision to remove them as well,
therefore I am submitting this patch.

3 files changed, 0 insertions, 309 deletions

diff --git a/test/pleroma/web/fed_sockets/fed_registry_test.exs b/test/pleroma/web/fed_sockets/fed_registry_test.exs
deleted file mode 100644
index 73aaced46..000000000
--- a/test/pleroma/web/fed_sockets/fed_registry_test.exs
+++ /dev/null
@@ -1,124 +0,0 @@
-# Pleroma: A lightweight social networking server
-# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
-# SPDX-License-Identifier: AGPL-3.0-only
-
-defmodule Pleroma.Web.FedSockets.FedRegistryTest do
-  use ExUnit.Case
-
-  alias Pleroma.Web.FedSockets
-  alias Pleroma.Web.FedSockets.FedRegistry
-  alias Pleroma.Web.FedSockets.SocketInfo
-
-  @good_domain "http://good.domain"
-  @good_domain_origin "good.domain:80"
-
-  setup do
-    start_supervised({Pleroma.Web.FedSockets.Supervisor, []})
-    build_test_socket(@good_domain)
-    Process.sleep(10)
-
-    :ok
-  end
-
-  describe "add_fed_socket/1 without conflicting sockets" do
-    test "can be added" do
-      Process.sleep(10)
-      assert {:ok, %SocketInfo{origin: origin}} = FedRegistry.get_fed_socket(@good_domain_origin)
-      assert origin == "good.domain:80"
-    end
-
-    test "multiple origins can be added" do
-      build_test_socket("http://anothergood.domain")
-      Process.sleep(10)
-
-      assert {:ok, %SocketInfo{origin: origin_1}} =
-               FedRegistry.get_fed_socket(@good_domain_origin)
-
-      assert {:ok, %SocketInfo{origin: origin_2}} =
-               FedRegistry.get_fed_socket("anothergood.domain:80")
-
-      assert origin_1 == "good.domain:80"
-      assert origin_2 == "anothergood.domain:80"
-      assert FedRegistry.list_all() |> Enum.count() == 2
-    end
-  end
-
-  describe "add_fed_socket/1 when duplicate sockets conflict" do
-    setup do
-      build_test_socket(@good_domain)
-      build_test_socket(@good_domain)
-      Process.sleep(10)
-      :ok
-    end
-
-    test "will be ignored" do
-      assert {:ok, %SocketInfo{origin: origin, pid: _pid_one}} =
-               FedRegistry.get_fed_socket(@good_domain_origin)
-
-      assert origin == "good.domain:80"
-
-      assert FedRegistry.list_all() |> Enum.count() == 1
-    end
-
-    test "the newer process will be closed" do
-      pid_two = build_test_socket(@good_domain)
-
-      assert {:ok, %SocketInfo{origin: origin, pid: _pid_one}} =
-               FedRegistry.get_fed_socket(@good_domain_origin)
-
-      assert origin == "good.domain:80"
-      Process.sleep(10)
-
-      refute Process.alive?(pid_two)
-
-      assert FedRegistry.list_all() |> Enum.count() == 1
-    end
-  end
-
-  describe "get_fed_socket/1" do
-    test "returns missing for unknown hosts" do
-      assert {:error, :missing} = FedRegistry.get_fed_socket("not_a_dmoain")
-    end
-
-    test "returns rejected for hosts previously rejected" do
-      "rejected.domain:80"
-      |> FedSockets.uri_for_origin()
-      |> FedRegistry.set_host_rejected()
-
-      assert {:error, :rejected} = FedRegistry.get_fed_socket("rejected.domain:80")
-    end
-
-    test "can retrieve a previously added SocketInfo" do
-      build_test_socket(@good_domain)
-      Process.sleep(10)
-      assert {:ok, %SocketInfo{origin: origin}} = FedRegistry.get_fed_socket(@good_domain_origin)
-      assert origin == "good.domain:80"
-    end
-
-    test "removes references to SocketInfos when the process crashes" do
-      assert {:ok, %SocketInfo{origin: origin, pid: pid}} =
-               FedRegistry.get_fed_socket(@good_domain_origin)
-
-      assert origin == "good.domain:80"
-
-      Process.exit(pid, :testing)
-      Process.sleep(100)
-      assert {:error, :missing} = FedRegistry.get_fed_socket(@good_domain_origin)
-    end
-  end
-
-  def build_test_socket(uri) do
-    Kernel.spawn(fn -> fed_socket_almost(uri) end)
-  end
-
-  def fed_socket_almost(origin) do
-    FedRegistry.add_fed_socket(origin)
-
-    receive do
-      :close ->
-        :ok
-    after
-      5_000 -> :timeout
-    end
-  end
-end
diff --git a/test/pleroma/web/fed_sockets/fetch_registry_test.exs b/test/pleroma/web/fed_sockets/fetch_registry_test.exs
deleted file mode 100644
index 7bd2d995a..000000000
--- a/test/pleroma/web/fed_sockets/fetch_registry_test.exs
+++ /dev/null
@@ -1,67 +0,0 @@
-# Pleroma: A lightweight social networking server
-# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
-# SPDX-License-Identifier: AGPL-3.0-only
-
-defmodule Pleroma.Web.FedSockets.FetchRegistryTest do
-  use ExUnit.Case
-
-  alias Pleroma.Web.FedSockets.FetchRegistry
-  alias Pleroma.Web.FedSockets.FetchRegistry.FetchRegistryData
-
-  @json_message "hello"
-  @json_reply "hello back"
-
-  setup do
-    start_supervised(
-      {Pleroma.Web.FedSockets.Supervisor,
-       [
-         ping_interval: 8,
-         connection_duration: 15,
-         rejection_duration: 5,
-         fed_socket_fetches: [default: 10, interval: 10]
-       ]}
-    )
-
-    :ok
-  end
-
-  test "fetches can be stored" do
-    uuid = FetchRegistry.register_fetch(@json_message)
-
-    assert {:error, :waiting} = FetchRegistry.check_fetch(uuid)
-  end
-
-  test "fetches can return" do
-    uuid = FetchRegistry.register_fetch(@json_message)
-    task = Task.async(fn -> FetchRegistry.register_fetch_received(uuid, @json_reply) end)
-
-    assert {:error, :waiting} = FetchRegistry.check_fetch(uuid)
-    Task.await(task)
-
-    assert {:ok, %FetchRegistryData{received_json: received_json}} =
-             FetchRegistry.check_fetch(uuid)
-
-    assert received_json == @json_reply
-  end
-
-  test "fetches are deleted once popped from stack" do
-    uuid = FetchRegistry.register_fetch(@json_message)
-    task = Task.async(fn -> FetchRegistry.register_fetch_received(uuid, @json_reply) end)
-    Task.await(task)
-
-    assert {:ok, %FetchRegistryData{received_json: received_json}} =
-             FetchRegistry.check_fetch(uuid)
-
-    assert received_json == @json_reply
-    assert {:ok, @json_reply} = FetchRegistry.pop_fetch(uuid)
-
-    assert {:error, :missing} = FetchRegistry.check_fetch(uuid)
-  end
-
-  test "fetches can time out" do
-    uuid = FetchRegistry.register_fetch(@json_message)
-    assert {:error, :waiting} = FetchRegistry.check_fetch(uuid)
-    Process.sleep(500)
-    assert {:error, :missing} = FetchRegistry.check_fetch(uuid)
-  end
-end
diff --git a/test/pleroma/web/fed_sockets/socket_info_test.exs b/test/pleroma/web/fed_sockets/socket_info_test.exs
deleted file mode 100644
index db3d6edcd..000000000
--- a/test/pleroma/web/fed_sockets/socket_info_test.exs
+++ /dev/null
@@ -1,118 +0,0 @@
-# Pleroma: A lightweight social networking server
-# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
-# SPDX-License-Identifier: AGPL-3.0-only
-
-defmodule Pleroma.Web.FedSockets.SocketInfoTest do
-  use ExUnit.Case
-
-  alias Pleroma.Web.FedSockets
-  alias Pleroma.Web.FedSockets.SocketInfo
-
-  describe "uri_for_origin" do
-    test "provides the fed_socket URL given the origin information" do
-      endpoint = "example.com:4000"
-      assert FedSockets.uri_for_origin(endpoint) =~ "ws://"
-      assert FedSockets.uri_for_origin(endpoint) =~ endpoint
-    end
-  end
-
-  describe "origin" do
-    test "will provide the origin field given a url" do
-      endpoint = "example.com:4000"
-      assert SocketInfo.origin("ws://#{endpoint}") == endpoint
-      assert SocketInfo.origin("http://#{endpoint}") == endpoint
-      assert SocketInfo.origin("https://#{endpoint}") == endpoint
-    end
-
-    test "will proide the origin field given a uri" do
-      endpoint = "example.com:4000"
-      uri = URI.parse("http://#{endpoint}")
-
-      assert SocketInfo.origin(uri) == endpoint
-    end
-  end
-
-  describe "touch" do
-    test "will update the TTL" do
-      endpoint = "example.com:4000"
-      socket = SocketInfo.build("ws://#{endpoint}")
-      Process.sleep(2)
-      touched_socket = SocketInfo.touch(socket)
-
-      assert socket.connected_until < touched_socket.connected_until
-    end
-  end
-
-  describe "expired?" do
-    setup do
-      start_supervised(
-        {Pleroma.Web.FedSockets.Supervisor,
-         [
-           ping_interval: 8,
-           connection_duration: 5,
-           rejection_duration: 5,
-           fed_socket_rejections: [lazy: true]
-         ]}
-      )
-
-      :ok
-    end
-
-    test "tests if the TTL is exceeded" do
-      endpoint = "example.com:4000"
-      socket = SocketInfo.build("ws://#{endpoint}")
-      refute SocketInfo.expired?(socket)
-      Process.sleep(10)
-
-      assert SocketInfo.expired?(socket)
-    end
-  end
-
-  describe "creating outgoing connection records" do
-    test "can be passed a string" do
-      assert %{conn_pid: :pid, origin: _origin} = SocketInfo.build("example.com:4000", :pid)
-    end
-
-    test "can be passed a URI" do
-      uri = URI.parse("http://example.com:4000")
-      assert %{conn_pid: :pid, origin: origin} = SocketInfo.build(uri, :pid)
-      assert origin =~ "example.com:4000"
-    end
-
-    test "will include the port number" do
-      assert %{conn_pid: :pid, origin: origin} = SocketInfo.build("http://example.com:4000", :pid)
-
-      assert origin =~ ":4000"
-    end
-
-    test "will provide the port if missing" do
-      assert %{conn_pid: :pid, origin: "example.com:80"} =
-               SocketInfo.build("http://example.com", :pid)
-
-      assert %{conn_pid: :pid, origin: "example.com:443"} =
-               SocketInfo.build("https://example.com", :pid)
-    end
-  end
-
-  describe "creating incoming connection records" do
-    test "can be passed a string" do
-      assert %{pid: _, origin: _origin} = SocketInfo.build("example.com:4000")
-    end
-
-    test "can be passed a URI" do
-      uri = URI.parse("example.com:4000")
-      assert %{pid: _, origin: _origin} = SocketInfo.build(uri)
-    end
-
-    test "will include the port number" do
-      assert %{pid: _, origin: origin} = SocketInfo.build("http://example.com:4000")
-
-      assert origin =~ ":4000"
-    end
-
-    test "will provide the port if missing" do
-      assert %{pid: _, origin: "example.com:80"} = SocketInfo.build("http://example.com")
-      assert %{pid: _, origin: "example.com:443"} = SocketInfo.build("https://example.com")
-    end
-  end
-end