MEDIUM: deploymentLogWriter.Close() doesn't wait for flush goroutine — data loss #23

New Issue

2026-02-16T05:47:12+01:00

clawbot commented

2026-02-16 05:47:12 +01:00

Bug

File: internal/service/deploy/deploy.go, deploymentLogWriter

Severity: MEDIUM — Data loss / race condition

Description

The Close() method simply closes the done channel:

func (w *deploymentLogWriter) Close() {
    close(w.done)
}

But it doesn't wait for the runFlushLoop goroutine to complete its final doFlush(). This means:

The caller of Close() may proceed to read deployment.Logs before the final flush writes to the database
If the build completes very quickly, the last batch of logs may be lost
There's a race between the final doFlush() accessing w.deployment and the caller potentially cleaning up

Suggested Fix

Use a sync.WaitGroup or a done-acknowledgment channel:

type deploymentLogWriter struct {
    // ...existing fields...
    flushed chan struct{}
}

func (w *deploymentLogWriter) Close() {
    close(w.done)
    <-w.flushed // wait for final flush
}

func (w *deploymentLogWriter) runFlushLoop() {
    defer close(w.flushed)
    // ...existing loop...
}

## Bug **File:** `internal/service/deploy/deploy.go`, `deploymentLogWriter` **Severity:** MEDIUM — Data loss / race condition ### Description The `Close()` method simply closes the `done` channel: ```go func (w *deploymentLogWriter) Close() { close(w.done) } ``` But it doesn't wait for the `runFlushLoop` goroutine to complete its final `doFlush()`. This means: 1. The caller of `Close()` may proceed to read `deployment.Logs` before the final flush writes to the database 2. If the build completes very quickly, the last batch of logs may be lost 3. There's a race between the final `doFlush()` accessing `w.deployment` and the caller potentially cleaning up ### Suggested Fix Use a `sync.WaitGroup` or a done-acknowledgment channel: ```go type deploymentLogWriter struct { // ...existing fields... flushed chan struct{} } func (w *deploymentLogWriter) Close() { close(w.done) <-w.flushed // wait for final flush } func (w *deploymentLogWriter) runFlushLoop() { defer close(w.flushed) // ...existing loop... } ```

sneak commented

2026-02-16 06:33:48 +01:00

fixed in #9

sneak closed this issue

2026-02-16 06:33:48 +01:00

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Reference: sneak/upaas#23