Creation of DTS example and passing of completionToken (#40)

* Creation of DTS example and passing of completionToken

Signed-off-by: Ryan Lettieri <[email protected]>

* Adressing review feedback

Signed-off-by: Ryan Lettieri <[email protected]>

* Reverting dapr readme

Signed-off-by: Ryan Lettieri <[email protected]>

* Adding accessTokenManager class for refreshing credential token

Signed-off-by: Ryan Lettieri <[email protected]>

* Adding comments to the example

Signed-off-by: Ryan Lettieri <[email protected]>

* Adding in requirement for azure-identity

Signed-off-by: Ryan Lettieri <[email protected]>

* Moving dts logic into its own module

Signed-off-by: Ryan Lettieri <[email protected]>

* Fixing whitesapce

Signed-off-by: Ryan Lettieri <[email protected]>

* Updating dts client to refresh token

Signed-off-by: Ryan Lettieri <[email protected]>

* Cleaning up construction of dts objects and improving examples

Signed-off-by: Ryan Lettieri <[email protected]>

* Migrating shared access token logic to new grpc class

Signed-off-by: Ryan Lettieri <[email protected]>

* Adding log statements to access_token_manager

Signed-off-by: Ryan Lettieri <[email protected]>

* breaking for loop when setting interceptors

Signed-off-by: Ryan Lettieri <[email protected]>

* Removing changes to client.py and adding additional steps to readme.md

Signed-off-by: Ryan Lettieri <[email protected]>

* Refactoring client and worker to pass around interceptors

Signed-off-by: Ryan Lettieri <[email protected]>

* Fixing import for DefaultClientInterceptorImpl

Signed-off-by: Ryan Lettieri <[email protected]>

* Adressing round 1 of feedback

Signed-off-by: Ryan Lettieri <[email protected]>

* Fixing interceptor issue

Signed-off-by: Ryan Lettieri <[email protected]>

* Moving some files around to remove dependencies

Signed-off-by: Ryan Lettieri <[email protected]>

* Adressing more feedback

Signed-off-by: Ryan Lettieri <[email protected]>

* More review feedback

Signed-off-by: Ryan Lettieri <[email protected]>

* Passing token credential as an argument rather than 2 strings

Signed-off-by: Ryan Lettieri <[email protected]>

* More review feedback for token passing

Signed-off-by: Ryan Lettieri <[email protected]>

* Addressing None comment and using correct metadata

Signed-off-by: Ryan Lettieri <[email protected]>

* Updating unit tests

Signed-off-by: Ryan Lettieri <[email protected]>

* Fixing the type for the unit test

Signed-off-by: Ryan Lettieri <[email protected]>

* Fixing grpc calls

Signed-off-by: Ryan Lettieri <[email protected]>

* Fix linter errors and update documentation

* Specifying version reqiuirement for pyproject.toml

Signed-off-by: Ryan Lettieri <[email protected]>

* Updating README

Signed-off-by: Ryan Lettieri <[email protected]>

* Adding comment for credential type

Signed-off-by: Ryan Lettieri <[email protected]>

---------

Signed-off-by: Ryan Lettieri <[email protected]>
Signed-off-by: Ryan Lettieri <[email protected]>
Co-authored-by: Chris Gillum <[email protected]>

Author: RyanLettieri

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Added `set_custom_status` orchestrator API ([#31](https://github.com/microsoft/durabletask-python/pull/31)) - contributed by [@famarting](https://github.com/famarting)
 - Added `purge_orchestration` client API ([#34](https://github.com/microsoft/durabletask-python/pull/34)) - contributed by [@famarting](https://github.com/famarting)
+- Added new `durabletask-azuremanaged` package for use with the [Durable Task Scheduler](https://techcommunity.microsoft.com/blog/appsonazureblog/announcing-limited-early-access-of-the-durable-task-scheduler-for-azure-durable-/4286526) - by [@RyanLettieri](https://github.com/RyanLettieri)
 
 ### Changes
 

README.md

@@ -1,15 +1,14 @@
-# Durable Task Client SDK for Python
+# Durable Task SDK for Python
 
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 [![Build Validation](https://github.com/microsoft/durabletask-python/actions/workflows/pr-validation.yml/badge.svg)](https://github.com/microsoft/durabletask-python/actions/workflows/pr-validation.yml)
 [![PyPI version](https://badge.fury.io/py/durabletask.svg)](https://badge.fury.io/py/durabletask)
 
-This repo contains a Python client SDK for use with the [Durable Task Framework for Go](https://github.com/microsoft/durabletask-go) and [Dapr Workflow](https://docs.dapr.io/developing-applications/building-blocks/workflow/workflow-overview/). With this SDK, you can define, schedule, and manage durable orchestrations using ordinary Python code.
+This repo contains a Python SDK for use with the [Azure Durable Task Scheduler](https://techcommunity.microsoft.com/blog/appsonazureblog/announcing-limited-early-access-of-the-durable-task-scheduler-for-azure-durable-/4286526) and the [Durable Task Framework for Go](https://github.com/microsoft/durabletask-go). With this SDK, you can define, schedule, and manage durable orchestrations using ordinary Python code.
 
 ⚠️ **This SDK is currently under active development and is not yet ready for production use.** ⚠️
 
-> Note that this project is **not** currently affiliated with the [Durable Functions](https://docs.microsoft.com/azure/azure-functions/durable/durable-functions-overview) project for Azure Functions. If you are looking for a Python SDK for Durable Functions, please see [this repo](https://github.com/Azure/azure-functions-durable-python).
-
+> Note that this SDK is **not** currently compatible with [Azure Durable Functions](https://docs.microsoft.com/azure/azure-functions/durable/durable-functions-overview). If you are looking for a Python SDK for Azure Durable Functions, please see [this repo](https://github.com/Azure/azure-functions-durable-python).
 
 ## Supported patterns
 

durabletask-azuremanaged/__init__.py

@@ -0,0 +1,30 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+from azure.core.credentials import TokenCredential
+
+from durabletask.azuremanaged.internal.durabletask_grpc_interceptor import \
+    DTSDefaultClientInterceptorImpl
+from durabletask.client import TaskHubGrpcClient
+
+
+# Client class used for Durable Task Scheduler (DTS)
+class DurableTaskSchedulerClient(TaskHubGrpcClient):
+    def __init__(self, *,
+                 host_address: str,
+                 taskhub: str,
+                 token_credential: TokenCredential,
+                 secure_channel: bool = True):
+
+        if not taskhub:
+            raise ValueError("Taskhub value cannot be empty. Please provide a value for your taskhub")
+
+        interceptors = [DTSDefaultClientInterceptorImpl(token_credential, taskhub)]
+
+        # We pass in None for the metadata so we don't construct an additional interceptor in the parent class
+        # Since the parent class doesn't use anything metadata for anything else, we can set it as None
+        super().__init__(
+            host_address=host_address,
+            secure_channel=secure_channel,
+            metadata=None,
+            interceptors=interceptors)

durabletask-azuremanaged/durabletask/azuremanaged/__init__.py

@@ -0,0 +1,49 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+from datetime import datetime, timedelta, timezone
+from typing import Optional
+
+from azure.core.credentials import AccessToken, TokenCredential
+
+import durabletask.internal.shared as shared
+
+
+# By default, when there's 10minutes left before the token expires, refresh the token
+class AccessTokenManager:
+
+    _token: Optional[AccessToken]
+
+    def __init__(self, token_credential: Optional[TokenCredential], refresh_interval_seconds: int = 600):
+        self._scope = "https://durabletask.io/.default"
+        self._refresh_interval_seconds = refresh_interval_seconds
+        self._logger = shared.get_logger("token_manager")
+
+        self._credential = token_credential
+
+        if self._credential is not None:
+            self._token = self._credential.get_token(self._scope)
+            self.expiry_time = datetime.fromtimestamp(self._token.expires_on, tz=timezone.utc)
+        else:
+            self._token = None
+            self.expiry_time = None
+
+    def get_access_token(self) -> Optional[AccessToken]:
+        if self._token is None or self.is_token_expired():
+            self.refresh_token()
+        return self._token
+
+    # Checks if the token is expired, or if it will expire in the next "refresh_interval_seconds" seconds.
+    # For example, if the token is created to have a lifespan of 2 hours, and the refresh buffer is set to 30 minutes,
+    # We will grab a new token when there're 30minutes left on the lifespan of the token
+    def is_token_expired(self) -> bool:
+        if self.expiry_time is None:
+            return True
+        return datetime.now(timezone.utc) >= (self.expiry_time - timedelta(seconds=self._refresh_interval_seconds))
+
+    def refresh_token(self):
+        if self._credential is not None:
+            self._token = self._credential.get_token(self._scope)
+
+            # Convert UNIX timestamp to timezone-aware datetime
+            self.expiry_time = datetime.fromtimestamp(self._token.expires_on, tz=timezone.utc)
+            self._logger.debug(f"Token refreshed. Expires at: {self.expiry_time}")

durabletask-azuremanaged/durabletask/azuremanaged/client.py

@@ -0,0 +1,41 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+import grpc
+from azure.core.credentials import TokenCredential
+
+from durabletask.azuremanaged.internal.access_token_manager import \
+    AccessTokenManager
+from durabletask.internal.grpc_interceptor import (
+    DefaultClientInterceptorImpl, _ClientCallDetails)
+
+
+class DTSDefaultClientInterceptorImpl (DefaultClientInterceptorImpl):
+    """The class implements a UnaryUnaryClientInterceptor, UnaryStreamClientInterceptor,
+    StreamUnaryClientInterceptor and StreamStreamClientInterceptor from grpc to add an
+    interceptor to add additional headers to all calls as needed."""
+
+    def __init__(self, token_credential: TokenCredential, taskhub_name: str):
+        self._metadata = [("taskhub", taskhub_name)]
+        super().__init__(self._metadata)
+
+        if token_credential is not None:
+            self._token_credential = token_credential
+            self._token_manager = AccessTokenManager(token_credential=self._token_credential)
+            access_token = self._token_manager.get_access_token()
+            if access_token is not None:
+                self._metadata.append(("authorization", f"Bearer {access_token.token}"))
+
+    def _intercept_call(
+            self, client_call_details: _ClientCallDetails) -> grpc.ClientCallDetails:
+        """Internal intercept_call implementation which adds metadata to grpc metadata in the RPC
+            call details."""
+        # Refresh the auth token if it is present and needed
+        if self._metadata is not None:
+            for i, (key, _) in enumerate(self._metadata):
+                if key.lower() == "authorization":  # Ensure case-insensitive comparison
+                    new_token = self._token_manager.get_access_token()  # Get the new token
+                    if new_token is not None:
+                        self._metadata[i] = ("authorization", f"Bearer {new_token.token}")  # Update the token
+
+        return super()._intercept_call(client_call_details)

durabletask-azuremanaged/durabletask/azuremanaged/internal/access_token_manager.py

@@ -0,0 +1,30 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+from azure.core.credentials import TokenCredential
+
+from durabletask.azuremanaged.internal.durabletask_grpc_interceptor import \
+    DTSDefaultClientInterceptorImpl
+from durabletask.worker import TaskHubGrpcWorker
+
+
+# Worker class used for Durable Task Scheduler (DTS)
+class DurableTaskSchedulerWorker(TaskHubGrpcWorker):
+    def __init__(self, *,
+                 host_address: str,
+                 taskhub: str,
+                 token_credential: TokenCredential,
+                 secure_channel: bool = True):
+
+        if not taskhub:
+            raise ValueError("The taskhub value cannot be empty.")
+
+        interceptors = [DTSDefaultClientInterceptorImpl(token_credential, taskhub)]
+
+        # We pass in None for the metadata so we don't construct an additional interceptor in the parent class
+        # Since the parent class doesn't use anything metadata for anything else, we can set it as None
+        super().__init__(
+            host_address=host_address,
+            secure_channel=secure_channel,
+            metadata=None,
+            interceptors=interceptors)

durabletask-azuremanaged/durabletask/azuremanaged/internal/durabletask_grpc_interceptor.py

@@ -0,0 +1,41 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# For more information on pyproject.toml, see https://peps.python.org/pep-0621/
+
+[build-system]
+requires = ["setuptools", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "durabletask.azuremanaged"
+version = "0.1b1"
+description = "Extensions for the Durable Task Python SDK for integrating with the Durable Task Scheduler in Azure"
+keywords = [
+    "durable",
+    "task",
+    "workflow",
+    "azure"
+]
+classifiers = [
+  "Development Status :: 3 - Alpha",
+  "Programming Language :: Python :: 3",
+  "License :: OSI Approved :: MIT License",
+]
+requires-python = ">=3.9"
+license = {file = "LICENSE"}
+readme = "README.md"
+dependencies = [
+    "durabletask>=0.2.0",
+    "azure-identity>=1.19.0"
+]
+
+[project.urls]
+repository = "https://github.com/microsoft/durabletask-python"
+changelog = "https://github.com/microsoft/durabletask-python/blob/main/CHANGELOG.md"
+
+[tool.setuptools.packages.find]
+include = ["durabletask.azuremanaged", "durabletask.azuremanaged.*"]
+
+[tool.pytest.ini_options]
+minversion = "6.0"

durabletask-azuremanaged/durabletask/azuremanaged/worker.py

@@ -6,7 +6,7 @@
 from dataclasses import dataclass
 from datetime import datetime
 from enum import Enum
-from typing import Any, Optional, TypeVar, Union
+from typing import Any, Optional, Sequence, TypeVar, Union
 
 import grpc
 from google.protobuf import wrappers_pb2
@@ -16,6 +16,7 @@
 import durabletask.internal.orchestrator_service_pb2_grpc as stubs
 import durabletask.internal.shared as shared
 from durabletask import task
+from durabletask.internal.grpc_interceptor import DefaultClientInterceptorImpl
 
 TInput = TypeVar('TInput')
 TOutput = TypeVar('TOutput')
@@ -96,8 +97,25 @@ def __init__(self, *,
                  metadata: Optional[list[tuple[str, str]]] = None,
                  log_handler: Optional[logging.Handler] = None,
                  log_formatter: Optional[logging.Formatter] = None,
-                 secure_channel: bool = False):
-        channel = shared.get_grpc_channel(host_address, metadata, secure_channel=secure_channel)
+                 secure_channel: bool = False,
+                 interceptors: Optional[Sequence[shared.ClientInterceptor]] = None):
+
+        # If the caller provided metadata, we need to create a new interceptor for it and
+        # add it to the list of interceptors.
+        if interceptors is not None:
+            interceptors = list(interceptors)
+            if metadata is not None:
+                interceptors.append(DefaultClientInterceptorImpl(metadata))
+        elif metadata is not None:
+            interceptors = [DefaultClientInterceptorImpl(metadata)]
+        else:
+            interceptors = None
+
+        channel = shared.get_grpc_channel(
+            host_address=host_address,
+            secure_channel=secure_channel,
+            interceptors=interceptors
+        )
         self._stub = stubs.TaskHubSidecarServiceStub(channel)
         self._logger = shared.get_logger("client", log_handler, log_formatter)
 
@@ -116,7 +134,7 @@ def schedule_new_orchestration(self, orchestrator: Union[task.Orchestrator[TInpu
             scheduledStartTimestamp=helpers.new_timestamp(start_at) if start_at else None,
             version=wrappers_pb2.StringValue(value=""),
             orchestrationIdReusePolicy=reuse_id_policy,
-            )
+        )
 
         self._logger.info(f"Starting new '{name}' instance with ID = '{req.instanceId}'.")
         res: pb.CreateInstanceResponse = self._stub.StartInstance(req)