analytics/lib/plausible_web/endpoint.ex

defmodule PlausibleWeb.Endpoint do
  use Plausible
  use Sentry.PlugCapture
  use Phoenix.Endpoint, otp_app: :plausible

  @session_options [
    # key to be patched
    key: "",
    store: :cookie,
    signing_salt: "I45i0SKHEku2f3tJh6y4v8gztrb/eG5KGCOe/o/AwFb7VHeuvDOn7AAq6KsdmOFM",
    # 5 years, this is super long but the SlidingSessionTimeout will log people out if they don't return for 2 weeks
    max_age: 60 * 60 * 24 * 365 * 5,
    extra: "SameSite=Lax"
    # domain added dynamically via RuntimeSessionAdapter, see below
  ]

  socket("/live", Phoenix.LiveView.Socket,
    websocket: [
      check_origin: true,
      connect_info: [
        :peer_data,
        :uri,
        :user_agent,
        session: {__MODULE__, :runtime_session_opts, []}
      ]
    ]
  )

  # Serve at "/" the static files from "priv/static" directory.
  #
  # You should set gzip to true if you are running phx.digest
  # when deploying your static files in production.
  plug(PlausibleWeb.Tracker)
  plug(PlausibleWeb.Favicon)

  static_paths = ~w(css js images favicon.ico)

  static_paths =
    on_full_build do
      # NOTE: The Cloud uses custom robots.txt from https://github.com/plausible/website: https://plausible.io/robots.txt
      static_paths
    else
      static_paths ++ ["robots.txt"]
    end

  plug(Plug.Static,
    at: "/",
    from: :plausible,
    gzip: false,
    only: static_paths
  )

  on_full_build do
    plug(Plug.Static,
      at: "/kaffy",
      from: :kaffy,
      gzip: false,
      only: ~w(assets)
    )
  end

  # Code reloading can be explicitly enabled under the
  # :code_reloader configuration of your endpoint.
  if code_reloading? do
    socket("/phoenix/live_reload/socket", Phoenix.LiveReloader.Socket)
    plug(Phoenix.LiveReloader)
    plug(Phoenix.CodeReloader)
  end

  plug(Plug.RequestId)
  plug(PromEx.Plug, prom_ex_module: Plausible.PromEx)
  plug(Plug.Telemetry, event_prefix: [:phoenix, :endpoint], log: false)

  plug(Plug.Parsers,
    parsers: [:urlencoded, :multipart, :json],
    pass: ["*/*"],
    json_decoder: Phoenix.json_library()
  )

  plug(Sentry.PlugContext)

  plug(Plug.MethodOverride)
  plug(Plug.Head)

  plug(:runtime_session)

  plug(CORSPlug)
  plug(PlausibleWeb.Router)

  def secure_cookie?, do: config!(:secure_cookie)

  def websocket_url() do
    config!(:websocket_url)
  end

  def runtime_session(conn, _opts) do
    Plug.run(conn, [{Plug.Session, runtime_session_opts()}])
  end

  def runtime_session_opts() do
    # `host()` provided by Phoenix.Endpoint's compilation hooks
    # is used to inject the domain - this way we can authenticate
    # websocket requests within single root domain, in case websocket_url()
    # returns a ws{s}:// scheme (in which case SameSite=Lax is not applicable).
    @session_options
    |> Keyword.put(:domain, host())
    |> Keyword.put(:key, "_plausible_#{Application.fetch_env!(:plausible, :environment)}")
    |> Keyword.put(:secure, secure_cookie?())
  end

  defp config!(key) do
    :plausible
    |> Application.fetch_env!(__MODULE__)
    |> Keyword.fetch!(key)
  end
end