Copy contents into the container

[gossi]

In my port of a library into elixir, my reference implementations are written in node and rust (et al). Both use testcontainers. Now, there is two functions, that do not exist in elixir:

• Rust: with_copy_to
• Node: withCopyContentToContainer()

This is semi-doable in elixir and in fact, the nginx container does it for testing:

testcontainers-elixir/test/support/nginx_container.ex

Line 17 in 644f5bd

Docker.Api.put_file(container.container_id, conn, "/tmp", "foo.txt", "Hello foo bar")

This was fine for me, to do it myself and not create a PR as an API is available... until I figured, there is a timing issue using it in after_build. I'm using it to create a file in combination with the with_cmd() to pass a parameter to point to that file and here is what happens:

1. Create container
2. Start container (with cmd)
3. Run after build to provide the file

This crashes when starting the container with executing the cmd fails. It is expecting a file, that is about to be provided.

Checking the node and rust implementation, the order is different:

1. Create container
2. Provide the files
3. Start container (with cmd)

... and that is how it works. I think to implement it in elixir, it would go in here:

testcontainers-elixir/lib/testcontainers.ex

Lines 368 to 377 in 644f5bd

	defp create_and_start_container(config, config_builder, state) do
	with :ok <- maybe_pull_image(config, state.conn),
	{:ok, id} <- Api.create_container(config, state.conn),
	:ok <- Api.start_container(id, state.conn),
	{:ok, container} <- Api.get_container(id, state.conn),
	:ok <- ContainerBuilder.after_start(config_builder, container, state.conn),
	:ok <- wait_for_container(container, config.wait_strategies || [], state.conn) do
	{:ok, container}
	end
	end

between create_container and start_container.

Apparently, node has a couple of "provide files" API methods. I dunno, what the elixir variant would take.

Any suggestions for this?