From db93455b07c03fad48bd6f46b46c869a4a73ebaf Mon Sep 17 00:00:00 2001
From: Thomas Citharel <tcit@tcit.fr>
Date: Thu, 27 Aug 2020 15:42:09 +0200
Subject: [PATCH] Fix getting remote IP behind reverse proxy

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
---
 config/config.exs       |  3 ++-
 lib/web/auth/context.ex | 10 ++++++++--
 lib/web/endpoint.ex     |  6 ++++++
 mix.exs                 |  1 +
 mix.lock                |  1 +
 5 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index 07e8a5871..9f75a3205 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -48,7 +48,8 @@ config :mobilizon, Mobilizon.Web.Endpoint,
   secret_key_base: "1yOazsoE0Wqu4kXk3uC5gu3jDbShOimTCzyFL3OjCdBmOXMyHX87Qmf3+Tu9s0iM",
   render_errors: [view: Mobilizon.Web.ErrorView, accepts: ~w(html json)],
   pubsub_server: Mobilizon.PubSub,
-  cache_static_manifest: "priv/static/manifest.json"
+  cache_static_manifest: "priv/static/manifest.json",
+  has_reverse_proxy: true
 
 # Upload configuration
 config :mobilizon, Mobilizon.Web.Upload,
diff --git a/lib/web/auth/context.ex b/lib/web/auth/context.ex
index 18f054075..209afd8fa 100644
--- a/lib/web/auth/context.ex
+++ b/lib/web/auth/context.ex
@@ -12,8 +12,14 @@ defmodule Mobilizon.Web.Auth.Context do
     opts
   end
 
-  def call(conn, _) do
-    context = %{ip: to_string(:inet_parse.ntoa(conn.remote_ip))}
+  def call(%{assigns: %{ip: _}} = conn, _opts), do: conn
+
+  def call(conn, _opts) do
+    set_user_and_ip_in_context(conn)
+  end
+
+  def set_user_and_ip_in_context(conn) do
+    context = %{ip: conn.remote_ip |> :inet.ntoa() |> to_string()}
 
     context =
       case Guardian.Plug.current_resource(conn) do
diff --git a/lib/web/endpoint.ex b/lib/web/endpoint.ex
index 932f9b999..7d4ebd421 100644
--- a/lib/web/endpoint.ex
+++ b/lib/web/endpoint.ex
@@ -19,6 +19,12 @@ defmodule Mobilizon.Web.Endpoint do
     longpoll: false
   )
 
+  endpoint_config = Application.get_env(:mobilizon, Mobilizon.Web.Endpoint)
+
+  if Keyword.get(endpoint_config, :has_reverse_proxy, false) == true do
+    plug(RemoteIp)
+  end
+
   plug(Mobilizon.Web.Plugs.UploadedMedia)
 
   # Serve at "/" the static files from "priv/static" directory.
diff --git a/mix.exs b/mix.exs
index 41cc45b1d..7ba01e834 100644
--- a/mix.exs
+++ b/mix.exs
@@ -134,6 +134,7 @@ defmodule Mobilizon.Mixfile do
       {:tesla, "~> 1.3.0"},
       {:sitemapper, "~> 0.4.0"},
       {:xml_builder, "~> 2.1.1", override: true},
+      {:remote_ip, "~> 0.2.0"},
       # Dev and test dependencies
       {:phoenix_live_reload, "~> 1.2", only: [:dev, :e2e]},
       {:ex_machina, "~> 2.3", only: [:dev, :test]},
diff --git a/mix.lock b/mix.lock
index 9b547867b..c79deffdb 100644
--- a/mix.lock
+++ b/mix.lock
@@ -117,6 +117,7 @@
   "postgrex": {:hex, :postgrex, "0.15.5", "aec40306a622d459b01bff890fa42f1430dac61593b122754144ad9033a2152f", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "ed90c81e1525f65a2ba2279dbcebf030d6d13328daa2f8088b9661eb9143af7f"},
   "progress_bar": {:hex, :progress_bar, "2.0.0", "447285f533b4b8717881fdb7160c7360c2f2ab57276f8904ce6d40482857e573", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm", "9d8b879f322fd5563e8e7ec39f1d02a9da3ffc36019f05287788744e88260fde"},
   "ranch": {:hex, :ranch, "1.7.1", "6b1fab51b49196860b733a49c07604465a47bdb78aa10c1c16a3d199f7f8c881", [:rebar3], [], "hexpm", "451d8527787df716d99dc36162fca05934915db0b6141bbdac2ea8d3c7afc7d7"},
+  "remote_ip": {:hex, :remote_ip, "0.2.1", "cd27cd8ea54ecaaf3532776ff4c5e353b3804e710302e88c01eadeaaf42e7e24", [:mix], [{:combine, "~> 0.10", [hex: :combine, repo: "hexpm", optional: false]}, {:inet_cidr, "~> 1.0", [hex: :inet_cidr, repo: "hexpm", optional: false]}, {:plug, "~> 1.5", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm", "2e7ab1a461cc3cd5719f37e116a08f45c8b8493923063631b164315d6b7ee8e0"},
   "rsa_ex": {:hex, :rsa_ex, "0.4.0", "e28dd7dc5236e156df434af0e4aa822384c8866c928e17b785d4edb7c253b558", [:mix], [], "hexpm", "40e1f08e8401da4be59a6dd0f4da30c42d5bb01703161f0208d839d97db27f4e"},
   "shortuuid": {:hex, :shortuuid, "2.1.2", "14dbafdb2f6c7213fdfcc05c7572384b5051a7b1621170018ad4c05504bd96c1", [:mix], [], "hexpm", "d9b0c4f37500ea5199b6275ece872e213e9f45a015caf4aa777cec84f63ad353"},
   "sitemapper": {:hex, :sitemapper, "0.4.0", "50061503ddc306aabcb984b377415961ff49696d70cd95081b20fa2a86f18ac4", [:mix], [{:ex_aws_s3, "~> 2.0", [hex: :ex_aws_s3, repo: "hexpm", optional: true]}, {:xml_builder, "~> 2.1.1", [hex: :xml_builder, repo: "hexpm", optional: false]}], "hexpm", "9bfe778635a6801e7762b185564df6a174d6016b15cbeaf50746e94ee55138c3"},