Add caller-provided logger configuration

[andystaples]

Why this is needed

Azure Functions 2.x clients and workers currently receive private core-SDK loggers with SDK-owned INFO stream handlers. Those records bypass the Azure Functions host logging pipeline, so host-level configuration cannot reliably control their level, routing, sampling, or telemetry correlation.

This change makes Functions-created components use the azure.durable_functions.client and azure.durable_functions.worker module loggers. They have no SDK-installed handlers and propagate normally, so the Functions host owns logging behavior as it does for the v1 SDK.

Changes

• route Azure Functions client and worker logs through the host-managed module logger hierarchy
• add an optional caller-provided logger to core and Azure Managed clients and workers
• deprecate log_handler and log_formatter while preserving their existing behavior
• document shared and isolated logger patterns, including handler and propagation trade-offs
• add regression coverage for logger forwarding, configuration preservation, legacy warnings, and Functions host logging

Validation

• python -m pytest tests\durabletask\test_logging.py tests\durabletask-azuremanaged\test_logging.py
• python -m pytest tests\azure-functions-durable\test_logging.py tests\azure-functions-durable\test_client_lifecycle.py tests\azure-functions-durable\test_client_compat.py tests\azure-functions-durable\test_worker_compat.py
• python -m flake8 durabletask tests\durabletask
• python -m flake8 durabletask-azuremanaged tests\durabletask-azuremanaged
• python -m flake8 azure-functions-durable tests\azure-functions-durable
• python -m pyright durabletask\client.py durabletask\worker.py durabletask\internal\shared.py durabletask-azuremanaged\durabletask\azuremanaged\client.py durabletask-azuremanaged\durabletask\azuremanaged\worker.py
• python -m pymarkdown -c .pymarkdown.json scan docs\features.md

[Copilot]

Pull request overview

This PR updates the Durable Task Python SDK and its Azure Managed / Azure Functions provider packages to let callers supply fully configured logging.Logger instances, and to ensure Azure Functions components emit logs through the host-managed azure.durable_functions.* logger hierarchy (rather than SDK-installed handlers).

Changes:

• Added an optional logger parameter to core and Azure Managed clients/workers, and ensured the SDK does not mutate caller-supplied logger configuration.
• Deprecated log_handler / log_formatter (with warnings) while preserving existing behavior when they’re used.
• Added documentation and tests covering logger forwarding and Azure Functions host logging behavior.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/durabletask/test_logging.py	New tests validating core components accept a caller-supplied logger unchanged and enforce incompatibility with legacy logging options.
tests/durabletask-azuremanaged/test_logging.py	New tests validating Azure Managed components forward a supplied logger unchanged.
tests/azure-functions-durable/test_logging.py	New tests validating Azure Functions components use the module logger (host-managed hierarchy).
durabletask/worker.py	Added logger parameter and updated worker documentation to deprecate legacy logging options.
durabletask/internal/shared.py	Extended get_logger() to accept a caller-supplied logger and emit deprecation warnings for legacy options.
durabletask/client.py	Added logger parameter to sync/async clients and forwarded it into shared logger creation.
durabletask-azuremanaged/durabletask/azuremanaged/worker.py	Added logger pass-through and updated Azure Managed worker docs for deprecation guidance.
durabletask-azuremanaged/durabletask/azuremanaged/client.py	Added logger pass-through to Azure Managed clients (sync + async).
durabletask-azuremanaged/CHANGELOG.md	Documented the new logger parameter and legacy option deprecations.
docs/features.md	Added SDK logging guidance, including propagation/handler duplication trade-offs.
CHANGELOG.md	Documented the new core logger parameter and legacy option deprecations.
azure-functions-durable/CHANGELOG.md	Documented that Functions logs now flow through the host-managed logger hierarchy.
azure-functions-durable/azure/durable_functions/worker.py	Introduced module logger and forwarded it into the base worker to avoid SDK-owned handlers.
azure-functions-durable/azure/durable_functions/client.py	Introduced module logger and forwarded it into the base clients to avoid SDK-owned handlers.

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[Bernd Verst (berndverst)]

Two non-blocking correctness issues remain in deprecation attribution and sync-client fail-fast cleanup. Otherwise the API shape, wrapper forwarding, Functions host routing, performance characteristics, documentation/changelogs, and coverage look sound. Local targeted tests, affected flake8 checks, and strict Pyright checks passed; all checks on this head are green.

[Bernd Verst (berndverst)]

The implementation and both previously reported correctness fixes now look sound. Two non-blocking documentation inconsistencies remain.

[Bernd Verst (berndverst)]

This heading now puts the pre-existing continue_as_new(new_version=...) entry (lines 23-25) under CHANGED, although it was an ADDED entry on main. Please move CHANGED below that entry. While touching these entries, please also preserve the changelog's unindented continuation style; the new wrapped lines here and in both provider changelogs currently use two-space indentation.

[Bernd Verst (berndverst)]

The guide still contains a second ### Logging configuration section at lines 640-661 that recommends log_handler/log_formatter and demonstrates log_handler=.... That contradicts this new deprecation guidance. Please merge, update, or remove the old section so the feature guide no longer recommends deprecated options.