Fixes content-type/length for stats stream=false

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit 855a056af7)

api/server/server.go

@@ -575,7 +575,16 @@ func (s *Server) getContainersStats(version version.Version, w http.ResponseWrit
 		return fmt.Errorf("Missing parameter")
 	}
 
-	return s.daemon.ContainerStats(vars["name"], boolValueOrDefault(r, "stream", true), ioutils.NewWriteFlusher(w))
+	stream := boolValueOrDefault(r, "stream", true)
+	var out io.Writer
+	if !stream {
+		w.Header().Set("Content-Type", "application/json")
+		out = w
+	} else {
+		out = ioutils.NewWriteFlusher(w)
+	}
+
+	return s.daemon.ContainerStats(vars["name"], stream, out)
 }
 
 func (s *Server) getContainersLogs(version version.Version, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

daemon/stats.go

@@ -15,31 +15,39 @@ func (daemon *Daemon) ContainerStats(name string, stream bool, out io.Writer) er
 	if err != nil {
 		return err
 	}
-	var pre_cpu_stats types.CpuStats
-	for first_v := range updates {
-		first_update := first_v.(*execdriver.ResourceStats)
-		first_stats := convertToAPITypes(first_update.Stats)
-		pre_cpu_stats = first_stats.CpuStats
-		pre_cpu_stats.SystemUsage = first_update.SystemUsage
-		break
-	}
-	enc := json.NewEncoder(out)
-	for v := range updates {
+
+	var preCpuStats types.CpuStats
+	getStat := func(v interface{}) *types.Stats {
 		update := v.(*execdriver.ResourceStats)
 		ss := convertToAPITypes(update.Stats)
-		ss.PreCpuStats = pre_cpu_stats
+		ss.PreCpuStats = preCpuStats
 		ss.MemoryStats.Limit = uint64(update.MemoryLimit)
 		ss.Read = update.Read
 		ss.CpuStats.SystemUsage = update.SystemUsage
-		pre_cpu_stats = ss.CpuStats
-		if err := enc.Encode(ss); err != nil {
+		preCpuStats = ss.CpuStats
+		return ss
+	}
+
+	enc := json.NewEncoder(out)
+
+	if !stream {
+		// prime the cpu stats so they aren't 0 in the final output
+		s := getStat(<-updates)
+
+		// now pull stats again with the cpu stats primed
+		s = getStat(<-updates)
+		err := enc.Encode(s)
+		daemon.UnsubscribeToContainerStats(name, updates)
+		return err
+	}
+
+	for v := range updates {
+		s := getStat(v)
+		if err := enc.Encode(s); err != nil {
 			// TODO: handle the specific broken pipe
 			daemon.UnsubscribeToContainerStats(name, updates)
 			return err
 		}
-		if !stream {
-			break
-		}
 	}
 	return nil
 }

integration-cli/docker_api_stats.go

@@ -1,48 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"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)
-	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")
-			}
-
-		}
-	case <-time.After(4 * time.Second):
-		c.Fatal("docker stats with no-stream timeout")
-	}
-
-}

integration-cli/docker_api_stats_test.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/docker/docker/api/types"
+	"github.com/go-check/check"
+)
+
+func (s *DockerSuite) TestCliStatsNoStreamGetCpu(c *check.C) {
+	out, _ := dockerCmd(c, "run", "-d", "busybox", "/bin/sh", "-c", "while true;do echo 'Hello'; usleep 100000; done")
+
+	id := strings.TrimSpace(out)
+	err := waitRun(id)
+	c.Assert(err, check.IsNil)
+
+	resp, body, err := sockRequestRaw("GET", fmt.Sprintf("/containers/%s/stats?stream=false", id), nil, "")
+	c.Assert(err, check.IsNil)
+	c.Assert(resp.ContentLength > 0, check.Equals, true, check.Commentf("should not use chunked encoding"))
+	c.Assert(resp.Header.Get("Content-Type"), check.Equals, "application/json")
+
+	var v *types.Stats
+	err = json.NewDecoder(body).Decode(&v)
+	c.Assert(err, check.IsNil)
+
+	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)
+	}
+}