Log streaming

[sjmiller609]

logs-demo.mov

will need update on CLI to use the generated SDK and handle SSE protocol (not showing "data:" and spurious newlines)

Shells out to "tail".

• Part of POSIX standard, included in GNU coreutils. Available on virtually all Unix/Linux systems.
• Handles optimization of reading from end of file without being too complicated
• Nearly the same code for with and without streaming

[github-actions]

✱ Stainless preview builds

This PR will update the hypeman SDKs with the following commit message.

feat: Generate log streaming

✅ hypeman-go studio · code

Your SDK built successfully.
generate ✅ → lint ✅ → test ✅

go get github.com/stainless-sdks/hypeman-go@f444c22bd9eb0ad06e66b3ca167171ddec2836e4

⚠️ hypeman-cli studio · code

There was a regression in your SDK.
generate ✅ → lint ❗ → test ⏳

---

This comment is auto-generated by GitHub Actions and is automatically kept up to date as you push.
Last updated: 2025-11-26 21:51:15 UTC

[mesa-dot-dev]

Mesa Description

TL;DR

Refactored instance log retrieval to use Server-Sent Events (SSE) for real-time streaming and introduced configurable log rotation functionality.

Why we made these changes

To provide real-time log streaming capabilities, optimize log retrieval by shelling out to tail, and implement robust log file management through rotation to prevent unbounded growth.

will need update on CLI to use the generated SDK and handle SSE protocol (not showing "data:" and spurious newlines)

Shells out to "tail".

• Part of POSIX standard, included in GNU coreutils. Available on virtually all Unix/Linux systems.
• Handles optimization of reading from end of file without being too complicated
• Nearly the same code for with and without streaming

What changed?

Log Streaming:

• cmd/api/api/instances.go: Refactored GetInstanceLogs to stream instance logs using SSE, managing headers and calling StreamInstanceLogs.
• lib/instances/logs.go: Refactored log management to use the external tail command for both initial tailing and continuous following.
• lib/instances/manager.go: Replaced GetInstanceLogs with StreamInstanceLogs in the Manager interface.
• openapi.yaml: Updated documentation for /instances/{id}/logs to clarify SSE usage and text/event-stream content type.
• stainless.yaml: Renamed the stream_logs operation to logs under the instances resource.

Log Rotation:

• cmd/api/config/config.go: Added new log rotation configuration parameters (LogMaxSize, LogMaxFiles, LogRotateInterval) to the Config struct.
• cmd/api/main.go: Incorporated log rotation, including validation for environment variables and a goroutine to schedule periodic rotations.
• lib/instances/logs.go: Introduced rotateLogIfNeeded function to manage log file rotation, including backup and truncation.
• lib/instances/manager.go: Added a new RotateLogs method to the Manager interface for rotating console logs.

OpenAPI/SDK Generation:

• lib/oapi/oapi.go: Generated OpenAPI client and server code updated due to specification changes.

Validation

• lib/instances/manager_test.go: Enhanced TestCreateAndDeleteInstance with a new test case to validate live log streaming functionality.

^{Description generated by Mesa. Update settings}

[mesa-dot-dev]

Performed full review of 71fea66...1cc134c

Analysis

1. Critical compilation error in cmd/api/main.go:196 due to incorrect variable reference - app.Config.logRotateInterval should be logRotateInterval (the field name uses uppercase 'L' in the struct).

2. Potential race condition in log streaming implementation - no coordination with instance lifecycle or rotation operations could lead to issues if an instance is deleted while streaming or during log rotation.

3. The external dependency on the POSIX tail command introduces runtime dependencies and testability challenges, though it's a pragmatic solution leveraging existing functionality.

4. Error handling in RotateLogs only returns the last error encountered, potentially masking multiple failures across different instances.

5. No backpressure handling in the log streaming implementation with a fixed buffer of 100 lines could cause goroutine blocking if consumers are slow.

Tip

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