feat: tests demonstrating copy file interfaces

core/README.rst

@@ -14,6 +14,8 @@ Testcontainers Core
 
 .. autoclass:: testcontainers.core.generic.DbContainer
 
+.. autoclass:: testcontainers.core.transferable.Transferable
+
 .. raw:: html
 
     <hr>

core/testcontainers/core/container.py

@@ -1,4 +1,7 @@
 import contextlib
+import io
+import pathlib
+import tarfile
 from os import PathLike
 from socket import socket
 from types import TracebackType
@@ -17,6 +20,7 @@
 from testcontainers.core.exceptions import ContainerConnectException, ContainerStartException
 from testcontainers.core.labels import LABEL_SESSION_ID, SESSION_ID
 from testcontainers.core.network import Network
+from testcontainers.core.transferable import Transferable
 from testcontainers.core.utils import is_arm, setup_logger
 from testcontainers.core.waiting_utils import wait_container_is_ready, wait_for_logs
 
@@ -69,6 +73,7 @@ def __init__(
         volumes: Optional[list[tuple[str, str, str]]] = None,
         network: Optional[Network] = None,
         network_aliases: Optional[list[str]] = None,
+        transferables: Optional[list[Transferable]] = None,
         **kwargs: Any,
     ) -> None:
         self.env = env or {}
@@ -96,6 +101,7 @@ def __init__(
             self.with_network_aliases(*network_aliases)
 
         self._kwargs = kwargs
+        self._transferables: list[Transferable] = transferables or []
 
     def with_env(self, key: str, value: str) -> Self:
         self.env[key] = value
@@ -196,6 +202,10 @@ def start(self) -> Self:
         )
 
         logger.info("Container started: %s", self._container.short_id)
+
+        for t in self._transferables:
+            self._transfer_into_container(t.source, t.destination_in_container, t.mode)
+
         return self
 
     def stop(self, force: bool = True, delete_volume: bool = True) -> None:
@@ -273,6 +283,50 @@ def _configure(self) -> None:
         # placeholder if subclasses want to define this and use the default start method
         pass
 
+    def with_copy_into_container(
+        self, file_content: Union[bytes, pathlib.Path], destination_in_container: str, mode: int = 0o644
+    ) -> Self:
+        self._transferables.append(Transferable(file_content, destination_in_container, mode))
+        return self
+
+    def copy_into_container(
+        self, file_content: Union[bytes, pathlib.Path], destination_in_container: str, mode: int = 0o644
+    ) -> None:
+        return self._transfer_into_container(file_content, destination_in_container, mode)
+
+    def _transfer_into_container(
+        self, source: Union[bytes, pathlib.Path], destination_in_container: str, mode: int
+    ) -> None:
+        if isinstance(source, bytes):
+            file_content = source
+        elif isinstance(source, pathlib.Path):
+            file_content = source.read_bytes()
+        else:
+            raise TypeError("source must be bytes or PathLike")
+
+        fileobj = io.BytesIO()
+        with tarfile.open(fileobj=fileobj, mode="w") as tar:
+            tarinfo = tarfile.TarInfo(name=destination_in_container)
+            tarinfo.size = len(file_content)
+            tarinfo.mode = mode
+            tar.addfile(tarinfo, io.BytesIO(file_content))
+        fileobj.seek(0)
+        assert self._container is not None
+        rv = self._container.put_archive(path="/", data=fileobj.getvalue())
+        assert rv is True
+
+    def copy_from_container(self, source_in_container: str, destination_on_host: pathlib.Path) -> None:
+        assert self._container is not None
+        tar_stream, _ = self._container.get_archive(source_in_container)
+
+        for chunk in tar_stream:
+            with tarfile.open(fileobj=io.BytesIO(chunk)) as tar:
+                for member in tar.getmembers():
+                    with open(destination_on_host, "wb") as f:
+                        fileobj = tar.extractfile(member)
+                        assert fileobj is not None
+                        f.write(fileobj.read())
+
 
 class Reaper:
     """

core/testcontainers/core/transferable.py

@@ -0,0 +1,14 @@
+import dataclasses
+import pathlib
+from typing import Union
+
+
+@dataclasses.dataclass
+class Transferable:
+    """
+    Wrapper class enabling copying files into a container
+    """
+
+    source: Union[bytes, pathlib.Path]
+    destination_in_container: str
+    mode: int = 0o644

core/tests/test_core.py

@@ -2,6 +2,7 @@
 from pathlib import Path
 
 from testcontainers.core.container import DockerContainer
+from testcontainers.core.transferable import Transferable
 
 
 def test_garbage_collection_is_defensive():
@@ -46,3 +47,119 @@ def test_docker_container_with_env_file():
             assert "ADMIN_EMAIL=admin@example.org" in output
             assert "ROOT_URL=example.org/app" in output
             print(output)
+
+
+def test_copy_file_into_container_at_runtime(tmp_path: Path):
+    # Given
+    my_file = tmp_path / "my_file"
+    my_file.write_text("hello world")
+    destination_in_container = "/tmp/my_file"
+
+    with DockerContainer("bash", command="sleep infinity") as container:
+        # When
+        container.copy_into_container(my_file, destination_in_container)
+        result = container.exec(f"cat {destination_in_container}")
+
+    # Then
+    assert result.exit_code == 0
+    assert result.output == b"hello world"
+
+
+def test_copy_file_into_container_at_startup(tmp_path: Path):
+    # Given
+    my_file = tmp_path / "my_file"
+    my_file.write_text("hello world")
+    destination_in_container = "/tmp/my_file"
+
+    container = DockerContainer("bash", command="sleep infinity")
+    container.with_copy_into_container(my_file, destination_in_container)
+
+    with container:
+        # When
+        result = container.exec(f"cat {destination_in_container}")
+
+    # Then
+    assert result.exit_code == 0
+    assert result.output == b"hello world"
+
+
+def test_copy_file_into_container_via_initializer(tmp_path: Path):
+    # Given
+    my_file = tmp_path / "my_file"
+    my_file.write_text("hello world")
+    destination_in_container = "/tmp/my_file"
+    transferables = [Transferable(my_file, destination_in_container)]
+
+    with DockerContainer("bash", command="sleep infinity", transferables=transferables) as container:
+        # When
+        result = container.exec(f"cat {destination_in_container}")
+
+    # Then
+    assert result.exit_code == 0
+    assert result.output == b"hello world"
+
+
+def test_copy_bytes_to_container_at_runtime():
+    # Given
+    file_content = b"hello world"
+    destination_in_container = "/tmp/my_file"
+
+    with DockerContainer("bash", command="sleep infinity") as container:
+        # When
+        container.copy_into_container(file_content, destination_in_container)
+
+        # Then
+        result = container.exec(f"cat {destination_in_container}")
+
+    assert result.exit_code == 0
+    assert result.output == b"hello world"
+
+
+def test_copy_bytes_to_container_at_startup():
+    # Given
+    file_content = b"hello world"
+    destination_in_container = "/tmp/my_file"
+
+    container = DockerContainer("bash", command="sleep infinity")
+    container.with_copy_into_container(file_content, destination_in_container)
+
+    with container:
+        # When
+        result = container.exec(f"cat {destination_in_container}")
+
+    # Then
+    assert result.exit_code == 0
+    assert result.output == b"hello world"
+
+
+def test_copy_bytes_to_container_via_initializer():
+    # Given
+    file_content = b"hello world"
+    destination_in_container = "/tmp/my_file"
+    transferables = [Transferable(file_content, destination_in_container)]
+
+    with DockerContainer("bash", command="sleep infinity", transferables=transferables) as container:
+        # When
+        result = container.exec(f"cat {destination_in_container}")
+
+    # Then
+    assert result.exit_code == 0
+    assert result.output == b"hello world"
+
+
+def test_copy_file_from_container(tmp_path: Path):
+    # Given
+    file_in_container = "/tmp/foo.txt"
+    destination_on_host = tmp_path / "foo.txt"
+    assert not destination_on_host.is_file()
+
+    with DockerContainer("bash", command="sleep infinity") as container:
+        result = container.exec(f'bash -c "echo -n hello world > {file_in_container}"')
+        assert result.exit_code == 0
+
+        # When
+        container.copy_from_container(file_in_container, destination_on_host)
+
+    # Then
+    assert destination_on_host.is_file()
+    assert destination_on_host.read_text() == "hello world"