feat(dcp): add support for S3 CopyObject API

Add support for S3 `CopyObject` API, binding Python and Rust clients
together. Bump versions for mountpoint-s3-client and mountpoint-s3-crt
(required to use the `CopyObject` API).

.gitignore

@@ -30,5 +30,8 @@ venv/
 *.egg
 multirun/
 
+# Unit test / coverage reports
+.hypothesis/
+
 # Prevent publishing file with third party licenses
 THIRD-PARTY-LICENSES

s3torchconnector/src/s3torchconnector/_s3client/_s3client.py

@@ -130,3 +130,11 @@ def head_object(self, bucket: str, key: str) -> ObjectInfo:
     def delete_object(self, bucket: str, key: str) -> None:
         log.debug(f"DeleteObject s3://{bucket}/{key}")
         self._client.delete_object(bucket, key)
+
+    def copy_object(
+        self, src_bucket: str, src_key: str, dst_bucket: str, dst_key: str
+    ) -> None:
+        log.debug(
+            f"CopyObject s3://{src_bucket}/{src_key} to s3://{dst_bucket}/{dst_key}"
+        )
+        return self._client.copy_object(src_bucket, src_key, dst_bucket, dst_key)

s3torchconnector/tst/unit/test_s3_client.py

@@ -60,6 +60,20 @@ def test_list_objects_log(s3_client: S3Client, caplog):
     assert f"ListObjects {S3_URI}" in caplog.messages
 
 
+def test_delete_object_log(s3_client: S3Client, caplog):
+    with caplog.at_level(logging.DEBUG):
+        s3_client.delete_object(TEST_BUCKET, TEST_KEY)
+    assert f"DeleteObject {S3_URI}" in caplog.messages
+
+
+def test_copy_object_log(s3_client: S3Client, caplog):
+    dst_bucket, dst_key = "dst_bucket", "dst_key"
+
+    with caplog.at_level(logging.DEBUG):
+        s3_client.copy_object(TEST_BUCKET, TEST_KEY, dst_bucket, dst_key)
+    assert f"CopyObject {S3_URI} to s3://{dst_bucket}/{dst_key}" in caplog.messages
+
+
 def test_s3_client_default_user_agent():
     s3_client = S3Client(region=TEST_REGION)
     expected_user_agent = f"s3torchconnector/{__version__}"

s3torchconnectorclient/Cargo.toml

@@ -19,8 +19,8 @@ built = "0.7"
 pyo3 = { version = "0.19.2" }
 pyo3-log = "0.8.3"
 futures = "0.3.28"
-mountpoint-s3-client = { version = "0.10.0", features = ["mock"] }
-mountpoint-s3-crt = "0.9.0"
+mountpoint-s3-client = { version = "0.11.0", features = ["mock"] }
+mountpoint-s3-crt = "0.10.0"
 log = "0.4.20"
 tracing = { version = "0.1.40", default-features = false, features = ["std", "log"] }
 tracing-subscriber = { version = "0.3.18", features = ["fmt", "env-filter"]}

s3torchconnectorclient/pyproject.toml

@@ -25,12 +25,14 @@ dependencies = []
 
 [project.optional-dependencies]
 test = [
+    "boto3",
     "pytest",
     "pytest-timeout",
     "hypothesis",
     "flake8",
     "black",
-    "mypy"
+    "mypy",
+    "Pillow"
 ]
 
 [tool.setuptools.packages]

s3torchconnectorclient/python/src/s3torchconnectorclient/_mountpoint_s3_client.pyi

@@ -35,6 +35,9 @@ class MountpointS3Client:
     ) -> ListObjectStream: ...
     def head_object(self, bucket: str, key: str) -> ObjectInfo: ...
     def delete_object(self, bucket: str, key: str) -> None: ...
+    def copy_object(
+        self, src_bucket: str, src_key: str, dst_bucket: str, dst_key: str
+    ) -> None: ...
 
 class MockMountpointS3Client:
     throughput_target_gbps: float

s3torchconnectorclient/python/tst/integration/conftest.py

@@ -4,6 +4,8 @@
 import io
 import os
 import random
+from dataclasses import dataclass, field
+from typing import Optional
 
 import boto3
 import numpy as np
@@ -18,33 +20,28 @@ def getenv(var: str, optional: bool = False) -> str:
     return v
 
 
-class BucketPrefixFixture(object):
+@dataclass
+class BucketPrefixFixture:
     """An S3 bucket/prefix and its contents for use in a single unit test. The prefix will be unique
     to this instance, so other concurrent tests won't affect its state."""
 
-    region: str
-    bucket: str
-    prefix: str
-    storage_class: str = None
-    endpoint_url: str = None
-
-    def __init__(
-        self,
-        region: str,
-        bucket: str,
-        prefix: str,
-        storage_class: str = None,
-        endpoint_url: str = None,
-    ):
-        self.bucket = bucket
-        self.prefix = prefix
-        self.region = region
-        self.storage_class = storage_class
-        self.endpoint_url = endpoint_url
-        self.contents = {}
-        session = boto3.Session(region_name=region)
+    name: str
+
+    region: str = getenv("CI_REGION")
+    bucket: str = getenv("CI_BUCKET")
+    prefix: str = getenv("CI_PREFIX")
+    storage_class: Optional[str] = getenv("CI_STORAGE_CLASS", optional=True)
+    endpoint_url: Optional[str] = getenv("CI_CUSTOM_ENDPOINT_URL", optional=True)
+    contents: dict = field(default_factory=dict)
+
+    def __post_init__(self):
+        assert self.prefix == "" or self.prefix.endswith("/")
+        session = boto3.Session(region_name=self.region)
         self.s3 = session.client("s3")
 
+        nonce = random.randrange(2**64)
+        self.prefix = f"{self.prefix}{self.name}/{nonce}/"
+
     @property
     def s3_uri(self):
         return f"s3://{self.bucket}/{self.prefix}"
@@ -55,34 +52,47 @@ def add(self, key: str, contents: bytes, **kwargs):
         self.s3.put_object(Bucket=self.bucket, Key=full_key, Body=contents, **kwargs)
         self.contents[full_key] = contents
 
+    def remove(self, key: str):
+        full_key = f"{self.prefix}{key}"
+        self.s3.delete_object(Bucket=self.bucket, Key=full_key)
+
     def __getitem__(self, index):
         return self.contents[index]
 
     def __iter__(self):
         return iter(self.contents)
 
 
-def get_test_bucket_prefix(name: str) -> BucketPrefixFixture:
-    """Create a new bucket/prefix fixture for the given test name."""
-    bucket = getenv("CI_BUCKET")
-    prefix = getenv("CI_PREFIX")
-    region = getenv("CI_REGION")
-    storage_class = getenv("CI_STORAGE_CLASS", optional=True)
-    endpoint_url = getenv("CI_CUSTOM_ENDPOINT_URL", optional=True)
-    assert prefix == "" or prefix.endswith("/")
+@dataclass
+class CopyBucketFixture(BucketPrefixFixture):
+    src_key: str = "src.txt"
+    dst_key: str = "dst.txt"
+
+    @property
+    def full_src_key(self):
+        return self.prefix + self.src_key
+
+    @property
+    def full_dst_key(self):
+        return self.prefix + self.dst_key
+
+
+def get_test_copy_bucket_fixture(name: str) -> CopyBucketFixture:
+    copy_bucket_fixture = CopyBucketFixture(name=name)
 
-    nonce = random.randrange(2**64)
-    prefix = f"{prefix}{name}/{nonce}/"
+    # set up / teardown
+    copy_bucket_fixture.add(copy_bucket_fixture.src_key, b"Hello, World!\n")
+    copy_bucket_fixture.remove(copy_bucket_fixture.dst_key)
 
-    return BucketPrefixFixture(region, bucket, prefix, storage_class, endpoint_url)
+    return copy_bucket_fixture
 
 
 @pytest.fixture
 def image_directory(request) -> BucketPrefixFixture:
     """Create a bucket/prefix fixture that contains a directory of random JPG image files."""
     NUM_IMAGES = 10
     IMAGE_SIZE = 100
-    fixture = get_test_bucket_prefix(f"{request.node.name}/image_directory")
+    fixture = BucketPrefixFixture(f"{request.node.name}/image_directory")
     for i in range(NUM_IMAGES):
         data = np.random.randint(0, 256, IMAGE_SIZE * IMAGE_SIZE * 3, np.uint8)
         data = data.reshape(IMAGE_SIZE, IMAGE_SIZE, 3)
@@ -100,23 +110,28 @@ def image_directory(request) -> BucketPrefixFixture:
 
 @pytest.fixture
 def sample_directory(request) -> BucketPrefixFixture:
-    fixture = get_test_bucket_prefix(f"{request.node.name}/sample_files")
+    fixture = BucketPrefixFixture(f"{request.node.name}/sample_files")
     fixture.add("hello_world.txt", b"Hello, World!\n")
     return fixture
 
 
 @pytest.fixture
 def put_object_tests_directory(request) -> BucketPrefixFixture:
-    fixture = get_test_bucket_prefix(f"{request.node.name}/put_integration_tests")
+    fixture = BucketPrefixFixture(f"{request.node.name}/put_integration_tests")
     fixture.add("to_overwrite.txt", b"before")
     return fixture
 
 
 @pytest.fixture
 def checkpoint_directory(request) -> BucketPrefixFixture:
-    return get_test_bucket_prefix(f"{request.node.name}/checkpoint_directory")
+    return BucketPrefixFixture(f"{request.node.name}/checkpoint_directory")
 
 
 @pytest.fixture
 def empty_directory(request) -> BucketPrefixFixture:
-    return get_test_bucket_prefix(f"{request.node.name}/empty_directory")
+    return BucketPrefixFixture(f"{request.node.name}/empty_directory")
+
+
+@pytest.fixture
+def copy_directory(request) -> CopyBucketFixture:
+    return get_test_copy_bucket_fixture(f"{request.node.name}/copy_directory")

s3torchconnectorclient/python/tst/integration/test_mountpoint_s3_integration.py

@@ -21,7 +21,7 @@
         ListObjectStream,
     )
 
-from conftest import BucketPrefixFixture
+from conftest import BucketPrefixFixture, CopyBucketFixture
 
 logging.basicConfig(
     format="%(levelname)s %(name)s %(asctime)-15s %(filename)s:%(lineno)d %(message)s"
@@ -404,6 +404,91 @@ def test_delete_object_invalid_bucket(
         )
 
 
+def test_copy_object(copy_directory: CopyBucketFixture):
+    full_src_key, full_dst_key = (
+        copy_directory.full_src_key,
+        copy_directory.full_dst_key,
+    )
+    bucket = copy_directory.bucket
+
+    client = MountpointS3Client(copy_directory.region, TEST_USER_AGENT_PREFIX)
+
+    client.copy_object(
+        src_bucket=bucket, src_key=full_src_key, dst_bucket=bucket, dst_key=full_dst_key
+    )
+
+    src_object = client.get_object(bucket, full_src_key)
+    dst_object = client.get_object(bucket, full_dst_key)
+
+    assert dst_object.key == full_dst_key
+    assert b"".join(dst_object) == b"".join(src_object)
+
+
+def test_copy_object_raises_when_source_bucket_does_not_exist(
+    copy_directory: CopyBucketFixture,
+):
+    full_src_key, full_dst_key = (
+        copy_directory.full_src_key,
+        copy_directory.full_dst_key,
+    )
+
+    client = MountpointS3Client(copy_directory.region, TEST_USER_AGENT_PREFIX)
+    # TODO: error message looks unexpected for Express One Zone, compared to the other tests for non-existing bucket or
+    #  key (see below)
+    error_message = (
+        "Client error: Forbidden: <no message>"
+        if copy_directory.storage_class == "EXPRESS_ONEZONE"
+        else "Service error: The object was not found"
+    )
+
+    with pytest.raises(S3Exception, match=error_message):
+        client.copy_object(
+            src_bucket=str(uuid.uuid4()),
+            src_key=full_src_key,
+            dst_bucket=copy_directory.bucket,
+            dst_key=full_dst_key,
+        )
+
+
+def test_copy_object_raises_when_destination_bucket_does_not_exist(
+    copy_directory: CopyBucketFixture,
+):
+    full_src_key, full_dst_key = (
+        copy_directory.full_src_key,
+        copy_directory.full_dst_key,
+    )
+
+    client = MountpointS3Client(copy_directory.region, TEST_USER_AGENT_PREFIX)
+
+    # NOTE: `copy_object` and its underlying implementation does not
+    # differentiate between `NoSuchBucket` and `NoSuchKey` errors.
+    with pytest.raises(S3Exception, match="Service error: The object was not found"):
+        client.copy_object(
+            src_bucket=copy_directory.bucket,
+            src_key=full_src_key,
+            dst_bucket=str(uuid.uuid4()),
+            dst_key=full_dst_key,
+        )
+
+
+def test_copy_object_raises_when_source_key_does_not_exist(
+    copy_directory: CopyBucketFixture,
+):
+    full_dst_key = copy_directory.full_dst_key
+
+    bucket = copy_directory.bucket
+
+    client = MountpointS3Client(copy_directory.region, TEST_USER_AGENT_PREFIX)
+
+    with pytest.raises(S3Exception, match="Service error: The object was not found"):
+        client.copy_object(
+            src_bucket=bucket,
+            src_key=str(uuid.uuid4()),
+            dst_bucket=bucket,
+            dst_key=full_dst_key,
+        )
+
+
 def _parse_list_result(stream: ListObjectStream, max_keys: int):
     object_infos = []
     i = 0