Add support for multiuser permissions in unix

[rads-1996]

Description

Adds folder permissions for Unix when multiple users are using the same system.

Fixes - #43414

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

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• Title of the pull request is clear and informative.
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Testing Guidelines

• Pull request includes test coverage for the included changes.

[Copilot]

Pull Request Overview

Adds multi-user Unix permission handling for local storage by introducing a helper to set parent (0o755) and storage (0o700) directory permissions and adds related test cases.

• Replaces direct chmod with _set_unix_permissions for Unix paths.
• Adds three tests covering success and two failure scenarios related to permission setting.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
sdk/monitor/azure-monitor-opentelemetry-exporter/azure/monitor/opentelemetry/exporter/_storage.py	Introduces _set_unix_permissions and updates Unix branch to use it.
sdk/monitor/azure-monitor-opentelemetry-exporter/tests/test_storage.py	Adds tests for multi-user Unix permission scenarios and error handling.

[rads-1996]

This might return an exception if the user details are not found, should we skip the user_segment in that case?

[hectorhdzg]

There are other unique properties that can be used, like time, new guid or similar

.NET use a hash with ikey, user name and process name
https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/Internals/PersistentStorage/StorageHelper.cs#L25

It will be good to have same logic in all exporters, having some language differentiator as well

[hectorhdzg]

Also this issue should be present in Node.js as well, only ikey is used to differentiate folders

[hectorhdzg]

Regarding what to do if some information is not available, we should try to build a hash using what is present to ensure problem is less likely to happen

[rads-1996]

Also this issue should be present in Node.js as well, only ikey is used to differentiate folders

Will create a separate task for it.

[rads-1996]

There are other unique properties that can be used, like time, new guid or similar

.NET use a hash with ikey, user name and process name https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/monitor/Azure.Monitor.OpenTelemetry.Exporter/src/Internals/PersistentStorage/StorageHelper.cs#L25

It will be good to have same logic in all exporters, having some language differentiator as well

When you say language differentiator, do you mean a difference in the functionality across languages or add a language attribute to this directory path?

[berland]

I have tested this PR, but it will still create the directory /tmp/Microsoft and /tmp/Microsoft/AzureMonitor without 0o777 permissions meaning it will fail when other users on the same machine tries to do the same thing.

[rads-1996]

I have tested this PR, but it will still create the directory /tmp/Microsoft and /tmp/Microsoft/AzureMonitor without 0o777 permissions meaning it will fail when other users on the same machine tries to do the same thing.

@berland I’m updating the implementation to align with the .NET SDK approach for creating a unique subdirectory. Once I push these changes, I’ll share an update so you can test and confirm if it works for you.

[berland]

Some comments to the current PR:

• The subdirectory structure provided by _AZURE_TEMPDIR_PREFIX seems pointless, now that it resides below /tmp/<somelongrandomstring>.
• Why not use tempfile.TemporaryDirectory() instead to make this PR less complex?