JuliusBrussee/caveman · error

objectstore: put

Error message

objectstore: put %q: %w

What it means

minioStore.Put wraps MinIO PutObject errors with 'objectstore: put %q: %w', naming the object key so the failing write is identifiable. The library throws it for any failure uploading the body: connectivity, auth, missing bucket, permissions, or size/policy limits.

Solutions

1. Inspect the wrapped cause for the class: connection refused (endpoint/network), AccessDenied (IAM), NoSuchBucket (bucket), timeout (ctx).
2. Confirm the bucket exists and credentials allow PutObject on it.
3. Check network/DNS from the service to the endpoint and retry transient failures with backoff.
4. Honor ctx deadlines — extend the timeout if legitimate uploads are being cut off.

Example fix

// before
if err := store.Put(ctx, key, body, ct); err != nil { return err } // wraps: AccessDenied
// after
if err := store.Put(ctx, key, body, ct); err != nil {
    var resp minio.ErrorResponse
    if errors.As(err, &resp) && resp.Code == "AccessDenied" {
        return fmt.Errorf("grant s3:PutObject on bucket %q to the configured key", resp.BucketName)
    }
    return err
}

// before Put: ensure context has sane deadline
ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()

err := store.Put(ctx, key, body, ct)
if err != nil {
    var resp minio.ErrorResponse
    if errors.As(err, &resp) {
        switch resp.Code {
        case "AccessDenied": // fix IAM
        case "NoSuchBucket": // recreate bucket
        default: // transient: retry with backoff
        }
    }
    if ctx.Err() == context.DeadlineExceeded { /* extend timeout */ }
}

When it happens

Trigger: Calling Store.Put (or the Probe path) where m.client.PutObject fails: network partition to the endpoint, wrong credentials, bucket deleted, IAM lacking s3:PutObject, request exceeding bucket policy size limits, or context deadline exceeded.

Common situations: Bucket auto-removed in dev environments; expired/rotated static credentials; MinIO restarted or scaled down in k8s; DNS resolution failures; long uploads killed by ctx timeout.

Understand the failure class

Background: "API error: {status}" and "HTTP 401/403/404/429/5xx" errors: non-2xx HTTP responses explained — this error's family across 27 libraries.

Related errors

• objectstore: get
• objectstore: production read/write/delete probe failed
• objectstore: read
• AbortError
• awscreds: read response

AI-assisted analysis of JuliusBrussee/caveman@3ee70a1026 (2026-09-20). Data as JSON: /api/errors/d9523e48c74703a5. Report an issue: GitHub.

Appendix: source

Thrown at shared/platform/objectstore/objectstore.go:278

	cleaned = true
	exists, err := store.Exists(ctx, key)
	if err != nil {
		return err
	}
	if exists {
		return errors.New("probe object still exists after purge")
	}
	return nil
}

func (m *minioStore) Put(ctx context.Context, key string, body []byte, contentType string) error {
	if contentType == "" {
		contentType = "application/octet-stream"
	}
	_, err := m.client.PutObject(ctx, m.bucket, key, bytes.NewReader(body), int64(len(body)),
		minio.PutObjectOptions{ContentType: contentType})
	if err != nil {
		return fmt.Errorf("objectstore: put %q: %w", key, err)
	}
	return nil
}

func (m *minioStore) Get(ctx context.Context, key string) ([]byte, error) {
	obj, err := m.client.GetObject(ctx, m.bucket, key, minio.GetObjectOptions{})
	if err != nil {
		return nil, fmt.Errorf("objectstore: get %q: %w", key, err)
	}
	defer obj.Close()
	maxBytes := int64(env.Int("CAVE_OBJECTSTORE_MAX_READ_BYTES", 64<<20))
	if maxBytes <= 0 {
		maxBytes = 64 << 20
	}
	body, err := io.ReadAll(io.LimitReader(obj, maxBytes+1))
	if err != nil {
		if minio.ToErrorResponse(err).Code == "NoSuchKey" {
			return nil, ErrNotFound

View on GitHub (pinned to 3ee70a1026)