Multiple fixes to 'docker stats' output:

* Add space between values in docker stats output for easier parsing

  Old output could not be parsed easily because there were columns
  that did not have any separator. Also values that are together
  without any space is difficult to read even for humans.

* Update unit.HumanSize comment to match what the does actually does

Signed-off-by: Otto Kekäläinen <otto@seravo.fi>

api/client/stats.go

@@ -110,7 +110,7 @@ func (s *containerStats) Display(w io.Writer) error {
 	if s.err != nil {
 		return s.err
 	}
-	fmt.Fprintf(w, "%s\t%.2f%%\t%s/%s\t%.2f%%\t%s/%s\n",
+	fmt.Fprintf(w, "%s\t%.2f%%\t%s / %s\t%.2f%%\t%s / %s\n",
 		s.Name,
 		s.CPUPercentage,
 		units.HumanSize(s.Memory), units.HumanSize(s.MemoryLimit),
@@ -142,7 +142,7 @@ func (cli *DockerCli) CmdStats(args ...string) error {
 			fmt.Fprint(cli.out, "\033[2J")
 			fmt.Fprint(cli.out, "\033[H")
 		}
-		io.WriteString(w, "CONTAINER\tCPU %\tMEM USAGE/LIMIT\tMEM %\tNET I/O\n")
+		io.WriteString(w, "CONTAINER\tCPU %\tMEM USAGE / LIMIT\tMEM %\tNET I/O\n")
 	}
 	for _, n := range names {
 		s := &containerStats{Name: n}

api/client/stats_unit_test.go

@@ -22,7 +22,7 @@ func TestDisplay(t *testing.T) {
 		t.Fatalf("c.Display() gave error: %s", err)
 	}
 	got := b.String()
-	want := "app\t30.00%\t104.9 MB/2.147 GB\t4.88%\t104.9 MB/838.9 MB\n"
+	want := "app\t30.00%\t104.9 MB / 2.147 GB\t4.88%\t104.9 MB / 838.9 MB\n"
 	if got != want {
 		t.Fatalf("c.Display() = %q, want %q", got, want)
 	}

docs/articles/runmetrics.md

@@ -21,13 +21,13 @@ and network IO metrics.
 The following is a sample output from the `docker stats` command
 
     $ docker stats redis1 redis2
-    CONTAINER           CPU %               MEM USAGE/LIMIT     MEM %               NET I/O
-    redis1              0.07%               796 KB/64 MB        1.21%               788 B/648 B
-    redis2              0.07%               2.746 MB/64 MB      4.29%               1.266 KB/648 B
+    CONTAINER           CPU %               MEM USAGE / LIMIT     MEM %               NET I/O
+    redis1              0.07%               796 KB / 64 MB        1.21%               788 B / 648 B
+    redis2              0.07%               2.746 MB / 64 MB      4.29%               1.266 KB / 648 B
 
 
 The [docker stats](/reference/commandline/stats/) reference page has
-more details about the `docker stats` command. 
+more details about the `docker stats` command.
 
 ## Control groups
 

docs/reference/commandline/stats.md

@@ -21,9 +21,9 @@ weight=1
 Running `docker stats` on multiple containers
 
     $ docker stats redis1 redis2
-    CONTAINER           CPU %               MEM USAGE/LIMIT     MEM %               NET I/O
-    redis1              0.07%               796 KB/64 MB        1.21%               788 B/648 B
-    redis2              0.07%               2.746 MB/64 MB      4.29%               1.266 KB/648 B
+    CONTAINER           CPU %               MEM USAGE / LIMIT     MEM %               NET I/O
+    redis1              0.07%               796 KB / 64 MB        1.21%               788 B / 648 B
+    redis2              0.07%               2.746 MB / 64 MB      4.29%               1.266 KB / 648 B
 
 
 The `docker stats` command will only return a live stream of data for running
@@ -31,4 +31,4 @@ containers. Stopped containers will not return any data.
 
 > **Note:**
 > If you want more detailed information about a container's resource
-> usage, use the API endpoint.
+> usage, use the API endpoint.

man/docker-stats.1.md

@@ -25,7 +25,6 @@ Display a live stream of one or more containers' resource usage statistics
 Run **docker stats** with multiple containers.
 
     $ docker stats redis1 redis2
-    CONTAINER           CPU %               MEM USAGE/LIMIT     MEM %               NET I/O
-    redis1              0.07%               796 KB/64 MB        1.21%               788 B/648 B
-    redis2              0.07%               2.746 MB/64 MB      4.29%               1.266 KB/648 B
-
+    CONTAINER           CPU %               MEM USAGE / LIMIT     MEM %               NET I/O
+    redis1              0.07%               796 KB / 64 MB        1.21%               788 B / 648 B
+    redis2              0.07%               2.746 MB / 64 MB      4.29%               1.266 KB / 648 B

pkg/units/size.go

@@ -49,7 +49,7 @@ func CustomSize(format string, size float64, base float64, _map []string) string
 }
 
 // HumanSize returns a human-readable approximation of a size
-// using SI standard (eg. "44kB", "17MB").
+// capped at 4 valid numbers (eg. "2.746 MB", "796 KB").
 func HumanSize(size float64) string {
 	return CustomSize("%.4g %s", size, 1000.0, decimapAbbrs)
 }