Merge pull request #13645 from calavera/fix_stats_flaky_test

Fix stats flaky test.

integration-cli/docker_api_stats.go

@@ -3,46 +3,31 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"strings"
+
 	"github.com/docker/docker/api/types"
 	"github.com/go-check/check"
-	"strings"
-	"time"
 )
 
 func (s *DockerSuite) TestCliStatsNoStreamGetCpu(c *check.C) {
 	out, _ := dockerCmd(c, "run", "-d", "--cpu-quota=2000", "busybox", "/bin/sh", "-c", "while true;do echo 'Hello';done")
 
 	id := strings.TrimSpace(out)
-	if err := waitRun(id); err != nil {
-		c.Fatal(err)
-	}
-	ch := make(chan error)
+	err := waitRun(id)
+	c.Assert(err, check.IsNil)
+
+	_, body, err := sockRequestRaw("GET", fmt.Sprintf("/containers/%s/stats?stream=false", id), nil, "")
+	c.Assert(err, check.IsNil)
+
 	var v *types.Stats
-	go func() {
-		_, body, err := sockRequestRaw("GET", fmt.Sprintf("/containers/%s/stats?stream=1", id), nil, "")
-		if err != nil {
-			ch <- err
-		}
-		dec := json.NewDecoder(body)
-		if err := dec.Decode(&v); err != nil {
-			ch <- err
-		}
-		ch <- nil
-	}()
-	select {
-	case e := <-ch:
-		if e == nil {
-			var cpuPercent = 0.0
-			cpuDelta := float64(v.CpuStats.CpuUsage.TotalUsage - v.PreCpuStats.CpuUsage.TotalUsage)
-			systemDelta := float64(v.CpuStats.SystemUsage - v.PreCpuStats.SystemUsage)
-			cpuPercent = (cpuDelta / systemDelta) * float64(len(v.CpuStats.CpuUsage.PercpuUsage)) * 100.0
-			if cpuPercent < 1.8 || cpuPercent > 2.2 {
-				c.Fatal("docker stats with no-stream get cpu usage failed")
-			}
+	err = json.NewDecoder(body).Decode(&v)
+	c.Assert(err, check.IsNil)
 
-		}
-	case <-time.After(4 * time.Second):
-		c.Fatal("docker stats with no-stream timeout")
+	var cpuPercent = 0.0
+	cpuDelta := float64(v.CpuStats.CpuUsage.TotalUsage - v.PreCpuStats.CpuUsage.TotalUsage)
+	systemDelta := float64(v.CpuStats.SystemUsage - v.PreCpuStats.SystemUsage)
+	cpuPercent = (cpuDelta / systemDelta) * float64(len(v.CpuStats.CpuUsage.PercpuUsage)) * 100.0
+	if cpuPercent == 0 {
+		c.Fatalf("docker stats with no-stream get cpu usage failed: was %v", cpuPercent)
 	}
-
 }