Add support for Fly.io deployments (#167)

Author: mickel8

guides/advanced/debugging.md

@@ -162,4 +162,4 @@ You can also configure PeerConnection to use a specific port range by doing
 
 Otherwise, the connection won't be established at all, or just in one direction.
 
-Read more in our [Deploying tutorial](./deploying.md#allow-udp-traffic-in-your-firewall)!
+Read more in our [Deploying tutorial](../deploying/bare.md#allow-udp-traffic-in-your-firewall)!

guides/advanced/deploying.md renamed to guides/deploying/bare.md

@@ -1,7 +1,7 @@
-# Deploying
+# Deploying on bare machines
 
 Deploying WebRTC applications can be cumbersome.
-Here are a few details you should keep in mind when trying to push your project into production.
+Here are a few details you should keep in mind when trying to push your project into production on a bare machine.
 
 ## Allow UDP traffic in your firewall
 
@@ -37,12 +37,6 @@ docker run -p 50000-50010/udp myapp
 Keep in mind that exporting a lot of ports might take a lot of time or even cause the Docker daemon to timeout.
 That's why we recommend using host's network.
 
-## Choose your cloud provider wisely
-
-Many cloud providers do not offer good support for UDP traffic.
-In such cases, deploying a WebRTC-based application might be impossible.
-We recommend using bare machines that you can configure as you need.
-
 ## Enable HTTPS in your frontend
 
 The server hosting your frontend site must have HTTPS enabled.
@@ -66,7 +60,7 @@ Read more [here](https://nginx.org/en/docs/http/websocket.html).
 
 ## Configure STUN servers
 
-If you are deploying your application behind a NAT, you have to configure a STUN 
+If you are deploying your application behind a NAT, you have to configure a STUN
 server that will allow it to discover its public IP address.
 In Elixir WebRTC this will be:
 
@@ -86,6 +80,6 @@ And as a TURN server, you can always use our [Rel](https://github.com/elixir-web
 
 If your application is deployed behind a very restrictive NAT, which should be very rare (e.g. a symmetric NAT),
 you will need to configure a TURN server.
-In most cases, TURN servers are needed on the client side as you don't have any control 
+In most cases, TURN servers are needed on the client side as you don't have any control
 over a network your clients connect from.
 For testing and experimental purposes, you can use our publicly available TURN called [Rel](https://github.com/elixir-webrtc/rel)!

guides/deploying/fly.md

@@ -0,0 +1,50 @@
+# Deploying on Fly.io
+
+Elixir WebRTC-based apps can be easily deployed on [Fly.io](https://fly.io)!
+
+There are just two things you need to do:
+
+* configure a STUN server both on the client and server side
+* use a custom Fly.io IP filter on the server side
+
+In theory, configuring a STUN server just on one side should be enough but we recommend doing it on both sides.
+
+In JavaScript code:
+
+```js
+pc = new RTCPeerConnection({
+  iceServers: [{ urls: "stun:stun.l.google.com:19302" }],
+});
+```
+
+In Elixir code:
+
+```elixir
+ip_filter = Application.get_env(:your_app, :ice_ip_filter)
+
+{:ok, pc} =
+  PeerConnection.start_link(
+    ice_ip_filter: ip_filter,
+    ice_servers: [%{urls: "stun:stun.l.google.com:19302"}]
+  )
+```
+
+In `runtime.exs`:
+
+```elixir
+if System.get_env("FLY_IO") do
+  config :your_app, ice_ip_filter: &ExWebRTC.ICE.FlyIpFilter.ip_filter/1
+end
+```
+
+In fly.toml:
+
+```toml
+[env]
+  # add one additional env
+  FLY_IO = 'true'
+```
+
+That's it!
+No special UDP port exports or dedicated IP address are needed.
+Just run `fly launch` and enjoy your deployment :)

lib/ex_webrtc/ice/fly_ip_filter.ex

@@ -0,0 +1,23 @@
+defmodule ExWebRTC.ICE.FlyIpFilter do
+  @moduledoc """
+  ICE IP filter for Fly.io deployments.
+
+  This module defines a single function, which filters IP addresses,
+  which ICE Agent will use as its host candidates.
+  It accepts only the IPv4 address that `fly-global-services` resolves to.
+  """
+
+  @spec ip_filter(:inet.ip_address()) :: boolean()
+  def ip_filter(ip_address) do
+    case :inet.gethostbyname(~c"fly-global-services") do
+      # Assume that fly-global-services has to resolve
+      # to a single ipv4 address.
+      # In other case, don't even try to connect.
+      {:ok, {:hostent, _, _, :inet, 4, [addr]}} ->
+        addr == ip_address
+
+      _ ->
+        false
+    end
+  end
+end

lib/ex_webrtc/peer_connection/configuration.ex

@@ -5,6 +5,7 @@ defmodule ExWebRTC.PeerConnection.Configuration do
 
   require Logger
 
+  alias ExICE.ICEAgent
   alias ExWebRTC.{RTPCodecParameters, SDPUtils}
   alias ExSDP.Attribute.{Extmap, FMTP, RTCPFeedback}
 
@@ -148,7 +149,7 @@ defmodule ExWebRTC.PeerConnection.Configuration do
           controlling_process: Process.dest(),
           ice_servers: [ice_server()],
           ice_transport_policy: :relay | :all,
-          ice_ip_filter: (:inet.ip_address() -> boolean()),
+          ice_ip_filter: ICEAgent.ip_filter(),
           ice_port_range: Enumerable.t(non_neg_integer()),
           audio_codecs: [RTPCodecParameters.t()],
           video_codecs: [RTPCodecParameters.t()],
@@ -162,7 +163,7 @@ defmodule ExWebRTC.PeerConnection.Configuration do
           controlling_process: Process.dest(),
           ice_servers: [ice_server()],
           ice_transport_policy: :relay | :all,
-          ice_ip_filter: (:inet.ip_address() -> boolean()),
+          ice_ip_filter: (:inet.ip_address() -> boolean()) | nil,
           ice_port_range: Enumerable.t(non_neg_integer()),
           audio_codecs: [RTPCodecParameters.t()],
           video_codecs: [RTPCodecParameters.t()],
@@ -239,7 +240,6 @@ defmodule ExWebRTC.PeerConnection.Configuration do
     feedbacks = Keyword.get(options, :rtcp_feedbacks, @default_rtcp_feedbacks)
 
     options
-    |> Keyword.put_new(:ice_ip_filter, fn _ -> true end)
     |> Keyword.put(:audio_extensions, Enum.map(audio_extensions, fn {_, ext} -> ext end))
     |> Keyword.put(:video_extensions, Enum.map(video_extensions, fn {_, ext} -> ext end))
     |> then(&struct(__MODULE__, &1))

mix.exs

@@ -57,7 +57,7 @@ defmodule ExWebRTC.MixProject do
   defp deps do
     [
       {:ex_sdp, "~> 1.0"},
-      {:ex_ice, "~> 0.8.0"},
+      {:ex_ice, github: "elixir-webrtc/ex_ice"},
       {:ex_dtls, "~> 0.16.0"},
       {:ex_libsrtp, "~> 0.7.1"},
       {:ex_rtp, "~> 0.4.0"},
@@ -80,25 +80,28 @@ defmodule ExWebRTC.MixProject do
       "simulcast",
       "modifying",
       "mastering_transceivers",
-      "deploying",
       "debugging"
     ]
 
+    deploying_guides = ["bare", "fly"]
+
     [
       main: "readme",
       logo: "logo.svg",
       extras:
         ["README.md"] ++
           Enum.map(intro_guides, &"guides/introduction/#{&1}.md") ++
-          Enum.map(advanced_guides, &"guides/advanced/#{&1}.md"),
+          Enum.map(advanced_guides, &"guides/advanced/#{&1}.md") ++
+          Enum.map(deploying_guides, &"guides/deploying/#{&1}.md"),
       assets: "guides/assets",
       source_ref: "v#{@version}",
       formatters: ["html"],
       before_closing_body_tag: &before_closing_body_tag/1,
       nest_modules_by_prefix: [ExWebRTC],
       groups_for_extras: [
         Introduction: Path.wildcard("guides/introduction/*.md"),
-        Advanced: Path.wildcard("guides/advanced/*.md")
+        Advanced: Path.wildcard("guides/advanced/*.md"),
+        Deploying: Path.wildcard("guides/deploying/*.md")
       ],
       groups_for_modules: [
         MEDIA: ~r"ExWebRTC\.Media\..*",

mix.lock

@@ -12,7 +12,7 @@
   "erlex": {:hex, :erlex, "0.2.7", "810e8725f96ab74d17aac676e748627a07bc87eb950d2b83acd29dc047a30595", [:mix], [], "hexpm", "3ed95f79d1a844c3f6bf0cea61e0d5612a42ce56da9c03f01df538685365efb0"},
   "ex_doc": {:hex, :ex_doc, "0.31.2", "8b06d0a5ac69e1a54df35519c951f1f44a7b7ca9a5bb7a260cd8a174d6322ece", [:mix], [{:earmark_parser, "~> 1.4.39", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.1", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "317346c14febaba9ca40fd97b5b5919f7751fb85d399cc8e7e8872049f37e0af"},
   "ex_dtls": {:hex, :ex_dtls, "0.16.0", "3ae38025ccc77f6db573e2e391602fa9bbc02253c137d8d2d59469a66cbe806b", [:mix], [{:bundlex, "~> 1.5.3", [hex: :bundlex, repo: "hexpm", optional: false]}, {:unifex, "~> 1.0", [hex: :unifex, repo: "hexpm", optional: false]}], "hexpm", "2a4e30d74c6ddf95cc5b796423293c06a0da295454c3823819808ff031b4b361"},
-  "ex_ice": {:hex, :ex_ice, "0.8.1", "4d5c911766ce92e13323b632a55d9ab821092f13fc2ebf236dc233c8c1f9a64c", [:mix], [{:elixir_uuid, "~> 1.0", [hex: :elixir_uuid, repo: "hexpm", optional: false]}, {:ex_stun, "~> 0.2.0", [hex: :ex_stun, repo: "hexpm", optional: false]}, {:ex_turn, "~> 0.1.0", [hex: :ex_turn, repo: "hexpm", optional: false]}], "hexpm", "8f10134e2eb7e6aebbf8fba0d5fcec56d8f8db3e94c3dde045feb463979c2dda"},
+  "ex_ice": {:git, "https://github.com/elixir-webrtc/ex_ice.git", "4c5190687e11b28a8209f2c930895647d0b2a64c", []},
   "ex_libsrtp": {:hex, :ex_libsrtp, "0.7.2", "211bd89c08026943ce71f3e2c0231795b99cee748808ed3ae7b97cd8d2450b6b", [:mix], [{:bunch, "~> 1.6", [hex: :bunch, repo: "hexpm", optional: false]}, {:bundlex, "~> 1.3", [hex: :bundlex, repo: "hexpm", optional: false]}, {:membrane_precompiled_dependency_provider, "~> 0.1.0", [hex: :membrane_precompiled_dependency_provider, repo: "hexpm", optional: false]}, {:unifex, "~> 1.1", [hex: :unifex, repo: "hexpm", optional: false]}], "hexpm", "2e20645d0d739a4ecdcf8d4810a0c198120c8a2f617f2b75b2e2e704d59f492a"},
   "ex_rtcp": {:hex, :ex_rtcp, "0.4.0", "f9e515462a9581798ff6413583a25174cfd2101c94a2ebee871cca7639886f0a", [:mix], [], "hexpm", "28956602cf210d692fcdaf3f60ca49681634e1deb28ace41246aee61ee22dc3b"},
   "ex_rtp": {:hex, :ex_rtp, "0.4.0", "1f1b5c1440a904706011e3afbb41741f5da309ce251cb986690ce9fd82636658", [:mix], [], "hexpm", "0f72d80d5953a62057270040f0f1ee6f955c08eeae82ac659c038001d7d5a790"},