feat: start a server with bentoml.Service instance (bentoml#3829)

```python
# service.py
svc = bentoml.Service(...)

if __name__ == "__main__":
    server = bentoml.HTTPServer(svc)
    server.start(blocking=True)
```


Co-authored-by: Aaron <[email protected]>

Author: parano

DEVELOPMENT.md

@@ -1,6 +1,6 @@
 # Developer Guide
 
-Before getting started, check out the `#bentoml-contributors` channel in the [BentoML community slack](https://l.linklyhq.com/l/ktOh).
+Before getting started, check out the `#bentoml-contributors` channel in the [BentoML community slack](https://l.bentoml.com/join-slack).
 
 If you are interested in contributing to existing issues and feature requets, check out the [good-first-issue](https://github.com/bentoml/BentoML/issues?q=is%3Aopen+is%3Aissue+label%3Agood-first-issue) and [help-wanted](https://github.com/bentoml/BentoML/issues?q=is%3Aopen+is%3Aissue+label%3Ahelp-wanted) issues list.
 

README.md

@@ -24,7 +24,7 @@ for the easiest and fastest way to deploy your bento.
 - [Examples](https://github.com/bentoml/BentoML/tree/main/examples) - Gallery of sample projects using BentoML
 - [ML Framework Guides](https://docs.bentoml.org/en/latest/frameworks/index.html) - Best practices and example usages by the ML framework of your choice
 - [Advanced Guides](https://docs.bentoml.org/en/latest/guides/index.html) - Learn about BentoML's internals, architecture and advanced features
-- Need help? [Join BentoML Community Slack 💬](https://l.linklyhq.com/l/ktOh)
+- Need help? [Join BentoML Community Slack 💬](https://l.bentoml.com/join-slack)
 
 ---
 
@@ -140,7 +140,7 @@ For a more detailed user guide, check out the [BentoML Tutorial](https://docs.be
 
 ## Community
 
-- For general questions and support, join the [community slack](https://l.linklyhq.com/l/ktOh).
+- For general questions and support, join the [community slack](https://l.bentoml.com/join-slack).
 - To receive release notification, star & watch the BentoML project on [GitHub](https://github.com/bentoml/BentoML).
 - To report a bug or suggest a feature request, use [GitHub Issues](https://github.com/bentoml/BentoML/issues/new/choose).
 - To stay informed with community updates, follow the [BentoML Blog](http://modelserving.com) and [@bentomlai](http://twitter.com/bentomlai) on Twitter.
@@ -149,7 +149,7 @@ For a more detailed user guide, check out the [BentoML Tutorial](https://docs.be
 
 There are many ways to contribute to the project:
 
-- If you have any feedback on the project, share it under the `#bentoml-contributors` channel in the [community slack](https://l.linklyhq.com/l/ktOh).
+- If you have any feedback on the project, share it under the `#bentoml-contributors` channel in the [community slack](https://l.bentoml.com/join-slack).
 - Report issues you're facing and "Thumbs up" on issues and feature requests that are relevant to you.
 - Investigate bugs and reviewing other developer's pull requests.
 - Contributing code or documentation to the project by submitting a GitHub pull request. Check out the [Development Guide](https://github.com/bentoml/BentoML/blob/main/DEVELOPMENT.md).

docs/source/guides/migration.rst

@@ -346,4 +346,4 @@ in one place, and enables advanced GitOps and CI/CD workflow.
 
 
 🎉 Ta-da, you have migrated your project to BentoML 1.0.0. Have more questions?
-`Join the BentoML Slack community <https://l.linklyhq.com/l/ktPp>`_.
+`Join the BentoML Slack community <https://l.bentoml.com/join-slack>`_.

requirements/tests-requirements.txt

@@ -19,4 +19,4 @@ protobuf<4.0dev
 grpcio
 grpcio-health-checking
 opentelemetry-instrumentation-grpc==0.35b0
-Pillow
+Pillow

src/bentoml/__init__.py

@@ -12,7 +12,7 @@
 
 To learn more, visit BentoML documentation at: http://docs.bentoml.org
 To get involved with the development, find us on GitHub: https://github.com/bentoml
-And join us in the BentoML slack community: https://l.linklyhq.com/l/ktOh
+And join us in the BentoML slack community: https://l.bentoml.com/join-slack
 """
 
 from typing import TYPE_CHECKING

src/bentoml/_internal/bento/bento.py

@@ -412,6 +412,15 @@ def from_bento_model(cls, bento_model: Model) -> BentoModelInfo:
         )
 
 
+def get_service_import_str(svc: Service | str):
+    from ..service import Service
+
+    if isinstance(svc, Service):
+        return svc.get_service_import_origin()[0]
+    else:
+        return svc
+
+
 @attr.frozen(repr=False)
 class BentoInfo:
     # for backward compatibility in case new fields are added to BentoInfo.
@@ -420,9 +429,7 @@ class BentoInfo:
     __omit_if_default__ = True
 
     tag: Tag
-    service: str = attr.field(
-        converter=lambda svc: svc if isinstance(svc, str) else svc._import_str
-    )
+    service: str = attr.field(converter=get_service_import_str)
     name: str = attr.field(init=False)
     version: str = attr.field(init=False)
     # using factory explicitly instead of default because omit_if_default is enabled for BentoInfo

src/bentoml/_internal/service/loader.py

@@ -14,7 +14,6 @@
 from ..tag import Tag
 from ..bento import Bento
 from ..models import ModelStore
-from .service import on_import_svc
 from .service import on_load_bento
 from ...exceptions import NotFound
 from ...exceptions import BentoMLException
@@ -169,11 +168,8 @@ def recover_standalone_env_change():
             instance, Service
         ), f'import target "{module_name}:{attrs_str}" is not a bentoml.Service instance'
 
-        on_import_svc(
-            svc=instance,
-            working_dir=working_dir,
-            import_str=f"{module_name}:{attrs_str}",
-        )
+        # set import_str for retrieving the service import origin
+        object.__setattr__(instance, "_import_str", f"{module_name}:{attrs_str}")
         return instance
     except ImportServiceError:
         if sys_path_modified and working_dir:

src/bentoml/_internal/service/service.py

@@ -1,6 +1,9 @@
 from __future__ import annotations
 
+import os
+import sys
 import typing as t
+import inspect
 import logging
 import importlib
 from typing import TYPE_CHECKING
@@ -119,6 +122,7 @@ class Service:
     # Working dir and Import path of the service, set when the service was imported
     _working_dir: str | None = attr.field(init=False, default=None)
     _import_str: str | None = attr.field(init=False, default=None)
+    _caller_module: str | None = attr.field(init=False, default=None)
 
     def __reduce__(self):
         """
@@ -181,7 +185,7 @@ def get_or_pull(bento_tag):
         else:
             from bentoml._internal.service.loader import import_service
 
-            return (import_service, (self._import_str, self._working_dir))
+            return (import_service, self.get_service_import_origin())
 
     def __init__(
         self,
@@ -226,6 +230,54 @@ def __init__(
             models=[] if models is None else models,
         )
 
+        # Set import origin info - import_str can not be determined at this stage yet as
+        # the variable name is only available in module vars after __init__ is returned
+        # get_service_import_origin below will use the _caller_module for retriving the
+        # correct import_str for this service
+        caller_module = inspect.currentframe().f_back.f_globals["__name__"]
+        object.__setattr__(self, "_caller_module", caller_module)
+        object.__setattr__(self, "_working_dir", os.getcwd())
+
+    def get_service_import_origin(self) -> tuple[str, str]:
+        """
+        Returns the module name and working directory of the service
+        """
+        if not self._import_str:
+            import_module = self._caller_module
+            if import_module == "__main__":
+                if hasattr(sys.modules["__main__"], "__file__"):
+                    import_module = sys.modules["__main__"].__file__
+                else:
+                    raise BentoMLException(
+                        "Failed to get service import origin, bentoml.Service object defined interactively in console or notebook is not supported"
+                    )
+
+            if self._caller_module not in sys.modules:
+                raise BentoMLException(
+                    "Failed to get service import origin, bentoml.Service object must be defined in a module"
+                )
+
+            for name, value in vars(sys.modules[self._caller_module]).items():
+                if value is self:
+                    object.__setattr__(self, "_import_str", f"{import_module}:{name}")
+                    break
+
+            if not self._import_str:
+                raise BentoMLException(
+                    "Failed to get service import origin, bentoml.Service object must be assigned to a variable at module level"
+                )
+
+        assert self._working_dir is not None
+
+        return self._import_str, self._working_dir
+
+    def is_service_importable(self) -> bool:
+        if self._caller_module == "__main__":
+            if not hasattr(sys.modules["__main__"], "__file__"):
+                return False
+
+        return True
+
     def api(
         self,
         input: IODescriptor[t.Any],  # pylint: disable=redefined-builtin
@@ -247,13 +299,15 @@ def decorator(func: D) -> D:
     def __str__(self):
         if self.bento:
             return f'bentoml.Service(tag="{self.tag}", ' f'path="{self.bento.path}")'
-        elif self._import_str and self._working_dir:
+
+        try:
+            import_str, working_dir = self.get_service_import_origin()
             return (
                 f'bentoml.Service(name="{self.name}", '
-                f'import_str="{self._import_str}", '
-                f'working_dir="{self._working_dir}")'
+                f'import_str="{import_str}", '
+                f'working_dir="{working_dir}")'
             )
-        else:
+        except BentoMLException:
             return (
                 f'bentoml.Service(name="{self.name}", '
                 f'runners=[{",".join([r.name for r in self.runners])}])'
@@ -263,16 +317,17 @@ def __repr__(self):
         return self.__str__()
 
     def __eq__(self, other: Service):
+        if self is other:
+            return True
+
         if self.bento and other.bento:
             return self.bento.tag == other.bento.tag
 
-        if (
-            self._working_dir == other._working_dir
-            and self._import_str == other._import_str
-        ):
-            return True
-
-        return False
+        try:
+            if self.get_service_import_origin() == other.get_service_import_origin():
+                return True
+        except BentoMLException:
+            return False
 
     @property
     def doc(self) -> str:
@@ -384,8 +439,3 @@ def add_grpc_handlers(self, handlers: list[grpc.GenericRpcHandler]) -> None:
 def on_load_bento(svc: Service, bento: Bento):
     object.__setattr__(svc, "bento", bento)
     object.__setattr__(svc, "tag", bento.info.tag)
-
-
-def on_import_svc(svc: Service, working_dir: str, import_str: str):
-    object.__setattr__(svc, "_working_dir", working_dir)
-    object.__setattr__(svc, "_import_str", import_str)

src/bentoml/server.py

@@ -12,8 +12,10 @@
 from simple_di import inject
 from simple_di import Provide
 
+from .exceptions import BentoMLException
 from ._internal.tag import Tag
 from ._internal.bento import Bento
+from ._internal.service import Service
 from ._internal.configuration.containers import BentoMLContainer
 
 if TYPE_CHECKING:
@@ -28,7 +30,7 @@
 
 
 class Server(ABC):
-    bento: str | Bento | Tag
+    servable: str | Bento | Tag | Service
     host: str
     port: int
 
@@ -40,7 +42,7 @@ class Server(ABC):
 
     def __init__(
         self,
-        bento: str | Bento | Tag,
+        servable: str | Bento | Tag | Service,
         serve_cmd: str,
         reload: bool,
         production: bool,
@@ -50,15 +52,37 @@ def __init__(
         working_dir: str | None,
         api_workers: int | None,
         backlog: int,
+        bento: str | Bento | Tag | Service | None = None,
     ):
-        self.bento = bento
+        if bento is not None:
+            if not servable:
+                logger.warning(
+                    "'bento' is deprecated, either remove it as a kwargs or pass '%s' as the first positional argument",
+                    bento,
+                )
+                servable = bento
+            else:
+                raise BentoMLException(
+                    "Cannot use both 'bento' and 'servable' as kwargs as 'bento' is deprecated."
+                )
 
-        if isinstance(bento, Bento):
-            bento_str = str(bento.tag)
-        elif isinstance(bento, Tag):
-            bento_str = str(bento)
+        self.servable = servable
+        # backward compatibility
+        self.bento = servable
+
+        working_dir = None
+        if isinstance(servable, Bento):
+            bento_str = str(servable.tag)
+        elif isinstance(servable, Tag):
+            bento_str = str(servable)
+        elif isinstance(servable, Service):
+            if not servable.is_service_importable():
+                raise BentoMLException(
+                    "Cannot use 'bentoml.Service' as a server if it is defined in interactive session or Jupyter Notebooks."
+                )
+            bento_str, working_dir = servable.get_service_import_origin()
         else:
-            bento_str = bento
+            bento_str = servable
 
         args: list[str] = [
             sys.executable,
@@ -74,6 +98,8 @@ def __init__(
             str(backlog),
         ]
 
+        if working_dir:
+            args.extend(["--working-dir", working_dir])
         if not production:
             args.append("--development")
         if reload:
@@ -183,7 +209,7 @@ class HTTPServer(Server):
     @inject
     def __init__(
         self,
-        bento: str | Bento | Tag,
+        bento: str | Bento | Tag | Service,
         reload: bool = False,
         production: bool = True,
         env: t.Literal["conda"] | None = None,
@@ -279,7 +305,7 @@ class GrpcServer(Server):
     @inject
     def __init__(
         self,
-        bento: str | Bento | Tag,
+        bento: str | Bento | Tag | Service,
         reload: bool = False,
         production: bool = True,
         env: t.Literal["conda"] | None = None,

tests/e2e/bento_server_http/tests/conftest.py

@@ -50,11 +50,13 @@ def fixture_server_config_file(request: FixtureRequest) -> str:
 
 
 @pytest.fixture(autouse=True, scope="package")
-def bento_directory(request):
+def bento_directory(request: FixtureRequest):
     bento_path = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
     os.chdir(bento_path)
+    sys.path.insert(0, bento_path)
     yield
     os.chdir(request.config.invocation_dir)
+    sys.path.pop(0)
 
 
 @pytest.fixture(scope="session")