agent: fix 'psn' usage

agent/server.go

@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/coreos/dbtester/agent/agentpb"
+	"github.com/gyuho/psn"
 	"golang.org/x/net/context"
 )
 
@@ -39,10 +40,13 @@ type transporterServer struct {
 	proxyCmd *exec.Cmd
 	proxyPid int64
 
+	metricsCSV *psn.CSV
+
 	// trigger log uploads to cloud storage
 	// this should be triggered before we shut down
 	// the agent server
 	uploadSig chan struct{}
+	csvReady  chan struct{}
 
 	// notified after all tests finish
 	notifier chan os.Signal
@@ -55,6 +59,7 @@ func NewServer() agentpb.TransporterServer {
 
 	return &transporterServer{
 		uploadSig: make(chan struct{}, 1),
+		csvReady:  make(chan struct{}),
 		notifier:  notifier,
 	}
 }
@@ -214,6 +219,7 @@ func (t *transporterServer) Transfer(ctx context.Context, r *agentpb.Request) (*
 		}
 
 		t.uploadSig <- struct{}{}
+		<-t.csvReady
 
 		if err := uploadLog(&globalFlags, t); err != nil {
 			plog.Warningf("uploadLog error %v", err)

agent/system_metrics.go

@@ -38,6 +38,7 @@ func collectMetrics(fs *flags, t *transporterServer) error {
 	if err := c.Add(); err != nil {
 		return err
 	}
+	t.metricsCSV = c
 
 	go func() {
 		for {
@@ -49,10 +50,16 @@ func collectMetrics(fs *flags, t *transporterServer) error {
 				}
 
 			case <-t.uploadSig:
-				plog.Info("upload signal received; returning")
+				plog.Infof("upload signal received; saving CSV at %q", t.metricsCSV.FilePath)
+				if err := t.metricsCSV.Save(); err != nil {
+					plog.Errorf("psn.CSV.Save error %v", err)
+				} else {
+					plog.Infof("CSV saved at %q", t.metricsCSV.FilePath)
+				}
+				close(t.csvReady)
 				return
 
-			case sig := <-notifier:
+			case sig := <-t.notifier:
 				plog.Infof("signal received %q", sig.String())
 				return
 			}