Skip to content

Fix file input in multi-node deployment #3130

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jonatanklosko merged 1 commit into from
Feb 3, 2026
Merged

Fix file input in multi-node deployment #3130

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
56 changes: 47 additions & 9 deletions lib/livebook/session.ex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -800,18 +800,35 @@ defmodule Livebook.Session do

"""
@spec register_file(pid(), String.t(), String.t(), keyword()) ::
{:ok, Runtime.file_ref()} | :error
{:ok, Runtime.file_ref()} | {:error, String.t()}
def register_file(pid, source_path, key, opts \\ []) do
opts = Keyword.validate!(opts, [:linked_client_id])

%{file_ref: file_ref, path: path} = GenServer.call(pid, :register_file_init)

with :ok <- File.mkdir_p(Path.dirname(path)),
:ok <- File.cp(source_path, path) do
with {:ok, file_ref, copy_into} <- GenServer.call(pid, :register_file_init),
:ok <- copy_file(source_path, copy_into) do
GenServer.cast(pid, {:register_file_finish, file_ref, key, opts[:linked_client_id]})
{:ok, file_ref}
else
_ -> :error
end
end

defp copy_file(source_path, {:path, path}) do
case File.cp(source_path, path) do
:ok -> :ok
{:error, reason} -> {:error, "copying file failed, reason: #{inspect(reason)}"}
end
end

defp copy_file(source_path, {:file, file_pid}) do
try do
source_path
|> File.stream!(64_000, [])
|> Enum.each(fn chunk -> IO.binwrite(file_pid, chunk) end)
Copy link
Contributor

@josevalim josevalim Feb 3, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think you can also use File.copy by passing two pids (the one in the open file and the one you received), or even a file path and a pid, and it will copy everything for you. But it is pretty much the same code as you have written here.

Copy link
Member Author

@jonatanklosko jonatanklosko Feb 3, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Nice! With File.copy we would need to make sure to close both files in all failure cases, so this may actually be more code :D


:ok
rescue
error -> {:error, "copying file failed, reason: #{inspect(error)}"}
after
File.close(file_pid)
end
end

Expand Down Expand Up @@ -1123,11 +1140,32 @@ defmodule Livebook.Session do
{:reply, :ok, maybe_save_notebook_sync(state)}
end

def handle_call(:register_file_init, _from, state) do
def handle_call(:register_file_init, {from_pid, _tag}, state) do
file_id = Livebook.Utils.random_id()
file_ref = {:file, file_id}
path = registered_file_path(state.session_id, file_ref)
reply = %{file_ref: file_ref, path: path}

dir = Path.dirname(path)

reply =
case File.mkdir_p(dir) do
:ok ->
if node(from_pid) == node() do
{:ok, file_ref, {:path, path}}
else
case File.open(path, [:binary, :write]) do
{:ok, file_pid} ->
{:ok, file_ref, {:file, file_pid}}

{:error, reason} ->
{:error, "failed to open file #{path}, reason: #{inspect(reason)}"}
end
end

{:error, reason} ->
{:error, "failed to create directory #{dir}, reason: #{inspect(reason)}"}
end

{:reply, reply, state}
end

Expand Down