From 7e63fe68f7912da32641b453f6a372dec9c2042d Mon Sep 17 00:00:00 2001
From: Jon Ayers <jon@coder.com>
Date: Fri, 3 Apr 2026 16:26:14 -0500
Subject: [PATCH] fix: avoid instantiating a logger if provided /dev/null
 (#24027)

- Adds some additional context to workspace traffic logging
- Fails traffic tests if 0 bytes read from connection
---
 cli/clilog/clilog.go                 |  2 +-
 cli/exp_scaletest.go                 |  3 +++
 scaletest/workspacetraffic/config.go |  6 ++++++
 scaletest/workspacetraffic/run.go    | 29 ++++++++++++++++++++++++++--
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/cli/clilog/clilog.go b/cli/clilog/clilog.go
index 50a7b1c834..81c87bb033 100644
--- a/cli/clilog/clilog.go
+++ b/cli/clilog/clilog.go
@@ -104,7 +104,7 @@ func (b *Builder) Build(inv *serpent.Invocation) (log slog.Logger, closeLog func
 
 	addSinkIfProvided := func(sinkFn func(io.Writer) slog.Sink, loc string) error {
 		switch loc {
-		case "":
+		case "", "/dev/null":
 		case "/dev/stdout":
 			sinks = append(sinks, sinkFn(inv.Stdout))
 
diff --git a/cli/exp_scaletest.go b/cli/exp_scaletest.go
index d46cca9b58..8173d76c3d 100644
--- a/cli/exp_scaletest.go
+++ b/cli/exp_scaletest.go
@@ -1401,6 +1401,9 @@ func (r *RootCmd) scaletestWorkspaceTraffic() *serpent.Command {
 				// Setup our workspace agent connection.
 				config := workspacetraffic.Config{
 					AgentID:       agent.ID,
+					WorkspaceID:   ws.ID,
+					WorkspaceName: ws.Name,
+					AgentName:     agent.Name,
 					BytesPerTick:  bytesPerTick,
 					Duration:      strategy.timeout,
 					TickInterval:  tickInterval,
diff --git a/scaletest/workspacetraffic/config.go b/scaletest/workspacetraffic/config.go
index 0948d35ea7..415eb2284d 100644
--- a/scaletest/workspacetraffic/config.go
+++ b/scaletest/workspacetraffic/config.go
@@ -12,6 +12,12 @@ import (
 type Config struct {
 	// AgentID is the workspace agent ID to which to connect.
 	AgentID uuid.UUID `json:"agent_id"`
+	// WorkspaceID is the workspace ID, used for logging.
+	WorkspaceID uuid.UUID `json:"workspace_id"`
+	// WorkspaceName is the workspace name, used for logging.
+	WorkspaceName string `json:"workspace_name"`
+	// AgentName is the agent name, used for logging.
+	AgentName string `json:"agent_name"`
 
 	// BytesPerTick is the number of bytes to send to the agent per tick.
 	BytesPerTick int64 `json:"bytes_per_tick"`
diff --git a/scaletest/workspacetraffic/run.go b/scaletest/workspacetraffic/run.go
index b3fedf385c..80cb83fd43 100644
--- a/scaletest/workspacetraffic/run.go
+++ b/scaletest/workspacetraffic/run.go
@@ -76,7 +76,12 @@ func (r *Runner) Run(ctx context.Context, _ string, logs io.Writer) (err error)
 		echo                = r.cfg.Echo
 	)
 
-	logger = logger.With(slog.F("agent_id", agentID))
+	logger = logger.With(
+		slog.F("agent_id", agentID),
+		slog.F("workspace_id", r.cfg.WorkspaceID),
+		slog.F("workspace_name", r.cfg.WorkspaceName),
+		slog.F("agent_name", r.cfg.AgentName),
+	)
 
 	logger.Debug(ctx, "config",
 		slog.F("reconnecting_pty_id", reconnect),
@@ -153,6 +158,14 @@ func (r *Runner) Run(ctx context.Context, _ string, logs io.Writer) (err error)
 	conn.readMetrics = r.cfg.ReadMetrics
 	conn.writeMetrics = r.cfg.WriteMetrics
 
+	logTrafficSummary := func() {
+		//nolint:gocritic
+		logger.Info(ctx, "traffic summary",
+			slog.F("actual_bytes_read", r.cfg.ReadMetrics.GetTotalBytes()),
+			slog.F("actual_bytes_written", r.cfg.WriteMetrics.GetTotalBytes()),
+		)
+	}
+
 	// Create a ticker for sending data to the conn.
 	tick := time.NewTicker(tickInterval)
 	defer tick.Stop()
@@ -179,10 +192,18 @@ func (r *Runner) Run(ctx context.Context, _ string, logs io.Writer) (err error)
 
 	var waitCloseTimeoutCh <-chan struct{}
 	deadlineCtxCh := deadlineCtx.Done()
+	deadlineReached := false
 	wchRef, rchRef := wch, rch
 	for {
 		if wchRef == nil && rchRef == nil {
-			logger.Info(ctx, "reading and writing to agent complete! Closing connection")
+			logTrafficSummary()
+			if !deadlineReached {
+				return xerrors.Errorf("test did not complete: context canceled after %s of %s",
+					time.Since(start).Truncate(time.Second), r.cfg.Duration)
+			}
+			if r.cfg.ReadMetrics.GetTotalBytes() == 0 {
+				return xerrors.Errorf("zero bytes read from agent")
+			}
 			return nil
 		}
 
@@ -192,23 +213,27 @@ func (r *Runner) Run(ctx context.Context, _ string, logs io.Writer) (err error)
 				slog.F("write_done", wchRef == nil),
 				slog.F("read_done", rchRef == nil),
 			)
+			logTrafficSummary()
 			return xerrors.Errorf("timed out waiting for read/write to complete: %w", ctx.Err())
 		case <-deadlineCtxCh:
 			go func() {
 				_ = closeConn()
 			}()
 			deadlineCtxCh = nil // Only trigger once.
+			deadlineReached = true
 			// Wait at most closeTimeout for the connection to close cleanly.
 			waitCtx, cancel := context.WithTimeout(context.Background(), waitCloseTimeout)
 			defer cancel() //nolint:revive // Only called once.
 			waitCloseTimeoutCh = waitCtx.Done()
 		case err = <-wchRef:
 			if err != nil {
+				logTrafficSummary()
 				return xerrors.Errorf("write to agent: %w", err)
 			}
 			wchRef = nil
 		case err = <-rchRef:
 			if err != nil {
+				logTrafficSummary()
 				return xerrors.Errorf("read from agent: %w", err)
 			}
 			rchRef = nil