From 3c779c6b64a7210b14d3a5f68ddc5a150333a899 Mon Sep 17 00:00:00 2001
From: Nikos Papadakis <nikos@papadakis.xyz>
Date: Fri, 23 Jun 2023 10:05:10 +0300
Subject: [PATCH] backend: register server api

---
 backend/lib/prymn/servers.ex                  | 31 ++++++++++-------
 backend/lib/prymn/servers/server.ex           | 13 +++++---
 .../prymn_web/components/core_components.ex   |  2 +-
 .../controllers/server_controller.ex          | 19 +++++++++++
 .../lib/prymn_web/live/server_live/index.ex   | 12 ++++---
 .../live/server_live/index.html.heex          | 13 +++++---
 .../prymn_web/live/server_live/show.html.heex | 33 +++++++++++--------
 backend/lib/prymn_web/router.ex               |  9 ++---
 .../20230609164352_create_servers.exs         | 10 +++---
 9 files changed, 95 insertions(+), 47 deletions(-)
 create mode 100644 backend/lib/prymn_web/controllers/server_controller.ex

diff --git a/backend/lib/prymn/servers.ex b/backend/lib/prymn/servers.ex
index d6d5bef..42aeff0 100644
--- a/backend/lib/prymn/servers.ex
+++ b/backend/lib/prymn/servers.ex
@@ -38,24 +38,33 @@ defmodule Prymn.Servers do
   def get_server!(id), do: Repo.get!(Server, id)
 
   @doc """
-  Creates a server.
-
-  ## Examples
-
-      iex> create_server(%{field: value})
-      {:ok, %Server{}}
-
-      iex> create_server(%{field: bad_value})
-      {:error, %Ecto.Changeset{}}
 
+  Start a new server connection with the app.
   """
   def create_server(attrs \\ %{}) do
-    # FIXME: Maybe use a cryptographically secure token (if UUID v4 is not one)?
-    %Server{connection_token: Ecto.UUID.generate()}
+    # Create a unique registration token
+    %Server{registration_token: :crypto.strong_rand_bytes(16)}
     |> Server.changeset(attrs)
     |> Repo.insert()
   end
 
+  @doc """
+  Registers a server using a registration token.
+  """
+  def register_server(token, public_ip) do
+    # TODO: Validate public ip
+
+    case Base.decode64(token) do
+      {:ok, token} ->
+        from(s in Server, where: s.registration_token == ^token, select: s)
+        |> Repo.one()
+        |> update_server(%{public_ip: public_ip})
+
+      :error ->
+        {:error, "token is not a valid base64 encoded string"}
+    end
+  end
+
   @doc """
   Updates a server.
 
diff --git a/backend/lib/prymn/servers/server.ex b/backend/lib/prymn/servers/server.ex
index 21b22ac..ae3dc11 100644
--- a/backend/lib/prymn/servers/server.ex
+++ b/backend/lib/prymn/servers/server.ex
@@ -4,10 +4,13 @@ defmodule Prymn.Servers.Server do
 
   schema "servers" do
     field :name, :string
-    field :ipv4, :string
-    field :ipv6, :string
+    field :public_ip, :string
     field :provider, Ecto.Enum, values: [:Hetzner, :Custom]
-    field :connection_token, Ecto.UUID, redact: true
+    field :registration_token, :binary, redact: true
+
+    field :connection_status, Ecto.Enum,
+      values: [:awaiting, :connecting, :installing, :connected, :disconnected],
+      default: :awaiting
 
     timestamps()
   end
@@ -15,8 +18,8 @@ defmodule Prymn.Servers.Server do
   @doc false
   def changeset(server, attrs) do
     server
-    |> cast(attrs, [:name, :provider])
-    |> validate_required([:name, :provider, :connection_token])
+    |> cast(attrs, [:name, :provider, :registration_token])
+    |> validate_required([:name, :provider])
     |> validate_inclusion(:provider, [:Custom], message: "Provider not available (yet)")
   end
 end
diff --git a/backend/lib/prymn_web/components/core_components.ex b/backend/lib/prymn_web/components/core_components.ex
index f9c99ca..c3830e6 100644
--- a/backend/lib/prymn_web/components/core_components.ex
+++ b/backend/lib/prymn_web/components/core_components.ex
@@ -477,7 +477,7 @@ defmodule PrymnWeb.CoreComponents do
               class="relative w-min p-0 hover:cursor-pointer"
               phx-click={@row_click && @row_click.(row)}
             >
-              <div class="block w-min py-4 pr-6">
+              <div class="block py-4 pr-6">
                 <span class="absolute -inset-y-px right-0 -left-4 group-hover:bg-zinc-50 sm:rounded-l-xl" />
                 <span class="relative hover:cursor-pointer"><%= @row_indicator.(row) %></span>
               </div>
diff --git a/backend/lib/prymn_web/controllers/server_controller.ex b/backend/lib/prymn_web/controllers/server_controller.ex
new file mode 100644
index 0000000..e0b5e92
--- /dev/null
+++ b/backend/lib/prymn_web/controllers/server_controller.ex
@@ -0,0 +1,19 @@
+defmodule PrymnWeb.ServerController do
+  use PrymnWeb, :controller
+
+  alias Prymn.Servers
+
+  @doc """
+  Used by clients to request a new server connection to the prymn backend
+  validating their registration token.
+  """
+  def register(conn, %{"token" => token, "ip" => ip}) do
+    case Servers.register_server(token, ip) do
+      {:ok, _server} ->
+        json(conn, %{"connected" => true})
+
+      {:error, error} ->
+        raise inspect(error)
+    end
+  end
+end
diff --git a/backend/lib/prymn_web/live/server_live/index.ex b/backend/lib/prymn_web/live/server_live/index.ex
index 99ddd39..d896183 100644
--- a/backend/lib/prymn_web/live/server_live/index.ex
+++ b/backend/lib/prymn_web/live/server_live/index.ex
@@ -24,11 +24,13 @@ defmodule PrymnWeb.ServerLive.Index do
   end
 
   @impl true
-  def handle_info({:connect, server}, socket) do
-    # TODO: Connect the new server:
-    #       For custom connections: will need to generate a new prompt for the user to execute
-    #       For API connections: the "prompt" will be automatic, but same execution server-side
-    {:noreply, stream_insert(socket, :servers, server)}
+  def handle_info({:connect, %Servers.Server{} = server}, socket) do
+    socket =
+      if server.provider == :Custom,
+        do: push_navigate(socket, to: ~p"/servers/#{server}"),
+        else: stream_insert(socket, :servers, server)
+
+    {:noreply, socket}
   end
 
   @impl true
diff --git a/backend/lib/prymn_web/live/server_live/index.html.heex b/backend/lib/prymn_web/live/server_live/index.html.heex
index 3f38d52..d10c240 100644
--- a/backend/lib/prymn_web/live/server_live/index.html.heex
+++ b/backend/lib/prymn_web/live/server_live/index.html.heex
@@ -12,15 +12,20 @@
   rows={@streams.servers}
   row_click={fn {_id, server} -> JS.navigate(~p"/servers/#{server}") end}
   row_indicator={
-    fn {_id, _server} ->
-      ~H(<span class="text-indigo-600">Connecting</span>)
+    fn
+      {_id, %Servers.Server{connection_status: :awaiting}} ->
+        ~H(<span class="text-grey-600">Awaiting connection</span>)
+
+      {_id, %Servers.Server{connection_status: :connecting}} ->
+        ~H(<span class="text-purple-600">Connecting</span>)
+
+      {_id, %Servers.Server{connection_status: :connected}} ->
+        ~H(<span class="text-green-600">Connected</span>)
     end
   }
   indicator_label="Status"
 >
   <:col :let={{_id, server}} label="Name"><%= server.name %></:col>
-  <:col :let={{_id, server}} label="IPv4"><%= server.ipv4 || "N/A" %></:col>
-  <:col :let={{_id, server}} label="IPv6"><%= server.ipv6 || "N/A" %></:col>
   <:action :let={{id, server}}>
     <.link
       phx-click={JS.push("delete", value: %{id: server.id}) |> hide("##{id}")}
diff --git a/backend/lib/prymn_web/live/server_live/show.html.heex b/backend/lib/prymn_web/live/server_live/show.html.heex
index 604a5f9..a21038a 100644
--- a/backend/lib/prymn_web/live/server_live/show.html.heex
+++ b/backend/lib/prymn_web/live/server_live/show.html.heex
@@ -1,18 +1,25 @@
 <.header>
-  <%= @server.name %>
-  <:subtitle>
-    <span>IPv4: <%= @server.ipv4 || "Not available" %></span>
-    <span :if={@server.ipv6}>IPv6: <%= @server.ipv6 %></span>
-  </:subtitle>
-  <:actions>
-    <.button>
-      New site
-    </.button>
-  </:actions>
+  Server <%= @server.name %>
 </.header>
 
-<div class="mt-10">
-  <h2 class="text-xl font-bold">Sites</h2>
-</div>
+<section :if={@server.connection_status == :awaiting} class="my-10">
+  <p class="mb-9">
+    Connect to your server using root credentials and execute the following command:
+  </p>
+  <div class="group inline-flex items-center rounded-lg bg-gray-800 p-4 pl-6 text-white">
+    <code class="flex gap-4">
+      <span class="select-none text-gray-500">#</span>
+      <span class="flex-1">
+        your command here that contains token: <%= Base.encode64(@server.registration_token) %>
+      </span>
+    </code>
+    <button type="button" tabindex="-1">
+      <.icon
+        name="hero-document-duplicate-solid"
+        class="invisible ml-4 animate-bounce text-gray-500 group-hover:visible"
+      />
+    </button>
+  </div>
+</section>
 
 <.back navigate={~p"/servers"}>Back to servers</.back>
diff --git a/backend/lib/prymn_web/router.ex b/backend/lib/prymn_web/router.ex
index 5cb50c4..0eaff59 100644
--- a/backend/lib/prymn_web/router.ex
+++ b/backend/lib/prymn_web/router.ex
@@ -25,10 +25,11 @@ defmodule PrymnWeb.Router do
     live "/servers/:id", ServerLive.Show
   end
 
-  # Other scopes may use custom stacks.
-  # scope "/api", PrymnWeb do
-  #   pipe_through :api
-  # end
+  scope "/api/v1", PrymnWeb do
+    pipe_through :api
+
+    post "/servers/register", ServerController, :register
+  end
 
   # Enable LiveDashboard and Swoosh mailbox preview in development
   if Application.compile_env(:prymn, :dev_routes) do
diff --git a/backend/priv/repo/migrations/20230609164352_create_servers.exs b/backend/priv/repo/migrations/20230609164352_create_servers.exs
index 93e046b..b097bad 100644
--- a/backend/priv/repo/migrations/20230609164352_create_servers.exs
+++ b/backend/priv/repo/migrations/20230609164352_create_servers.exs
@@ -2,14 +2,16 @@ defmodule Prymn.Repo.Migrations.CreateServers do
   use Ecto.Migration
 
   def change do
-    create table(:servers) do
+    create table("servers") do
       add :name, :string
-      add :ipv4, :string
-      add :ipv6, :string
+      add :public_ip, :string
       add :provider, :string
-      add :connection_token, :binary
+      add :connection_status, :string
+      add :registration_token, :binary
 
       timestamps()
     end
+
+    create index("servers", [:registration_token], unique: true)
   end
 end