Add an API endpoint to install a new frontend

lib/pleroma/frontend.ex

@@ -0,0 +1,108 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Frontend do
+  alias Pleroma.Config
+
+  require Logger
+
+  def install(name, opts \\ []) do
+    cmd_frontend_info = %{
+      "ref" => opts[:ref],
+      "build_url" => opts[:build_url],
+      "build_dir" => opts[:build_dir]
+    }
+
+    config_frontend_info = Config.get([:frontends, :available, name], %{})
+
+    frontend_info =
+      Map.merge(config_frontend_info, cmd_frontend_info, fn _key, config, cmd ->
+        # This only overrides things that are actually set
+        cmd || config
+      end)
+
+    ref = frontend_info["ref"]
+
+    unless ref do
+      raise "No ref given or configured"
+    end
+
+    dest = Path.join([dir(), name, ref])
+
+    label = "#{name} (#{ref})"
+    tmp_dir = Path.join(dir(), "tmp")
+
+    with {_, :ok} <-
+           {:download_or_unzip, download_or_unzip(frontend_info, tmp_dir, opts[:file])},
+         Logger.info("Installing #{label} to #{dest}"),
+         :ok <- install_frontend(frontend_info, tmp_dir, dest) do
+      File.rm_rf!(tmp_dir)
+      Logger.info("Frontend #{label} installed to #{dest}")
+    else
+      {:download_or_unzip, _} ->
+        Logger.info("Could not download or unzip the frontend")
+
+      _e ->
+        Logger.info("Could not install the frontend")
+    end
+  end
+
+  def dir(opts \\ []) do
+    if is_nil(opts[:static_dir]) do
+      Pleroma.Config.get!([:instance, :static_dir])
+    else
+      opts[:static_dir]
+    end
+    |> Path.join("frontends")
+  end
+
+  defp download_or_unzip(frontend_info, temp_dir, nil),
+    do: download_build(frontend_info, temp_dir)
+
+  defp download_or_unzip(_frontend_info, temp_dir, file) do
+    with {:ok, zip} <- File.read(Path.expand(file)) do
+      unzip(zip, temp_dir)
+    end
+  end
+
+  def unzip(zip, dest) do
+    with {:ok, unzipped} <- :zip.unzip(zip, [:memory]) do
+      File.rm_rf!(dest)
+      File.mkdir_p!(dest)
+
+      Enum.each(unzipped, fn {filename, data} ->
+        path = filename
+
+        new_file_path = Path.join(dest, path)
+
+        new_file_path
+        |> Path.dirname()
+        |> File.mkdir_p!()
+
+        File.write!(new_file_path, data)
+      end)
+    end
+  end
+
+  defp download_build(frontend_info, dest) do
+    Logger.info("Downloading pre-built bundle for #{frontend_info["name"]}")
+    url = String.replace(frontend_info["build_url"], "${ref}", frontend_info["ref"])
+
+    with {:ok, %{status: 200, body: zip_body}} <-
+           Pleroma.HTTP.get(url, [], pool: :media, recv_timeout: 120_000) do
+      unzip(zip_body, dest)
+    else
+      {:error, e} -> {:error, e}
+      e -> {:error, e}
+    end
+  end
+
+  defp install_frontend(frontend_info, source, dest) do
+    from = frontend_info["build_dir"] || "dist"
+    File.rm_rf!(dest)
+    File.mkdir_p!(dest)
+    File.cp_r!(Path.join([source, from]), dest)
+    :ok
+  end
+end