Podman pod stats -- fix GO template output

Go templates were not being processed or printed correctly for podman
pod stats.  Added the ability to do templates as well as honor the
table identifier.

Fixes #2258

Signed-off-by: baude <bbaude@redhat.com>

3 files changed, 138 insertions, 24 deletions

diff --git a/cmd/podman/pod_stats.go b/cmd/podman/pod_stats.go
index ccbcf9f7c..02dee68ac 100644
--- a/cmd/podman/pod_stats.go
+++ b/cmd/podman/pod_stats.go
@@ -2,7 +2,11 @@ package main
 
 import (
 	"fmt"
+	"html/template"
+	"os"
+	"reflect"
 	"strings"
+	"text/tabwriter"
 	"time"
 
 	"encoding/json"
@@ -136,6 +140,25 @@ func podStatsCmd(c *cliconfig.PodStatsValues) error {
 		step = 0
 	}
 
+	headerNames := make(map[string]string)
+	if c.Format != "" {
+		// Make a map of the field names for the headers
+		v := reflect.ValueOf(podStatOut{})
+		t := v.Type()
+		for i := 0; i < t.NumField(); i++ {
+			value := strings.ToUpper(splitCamelCase(t.Field(i).Name))
+			switch value {
+			case "CPU":
+				value = value + " %"
+			case "MEM":
+				value = value + " %"
+			case "MEM USAGE":
+				value = "MEM USAGE / LIMIT"
+			}
+			headerNames[t.Field(i).Name] = value
+		}
+	}
+
 	for i := 0; i < times; i += step {
 		var newStats []*libpod.PodContainerStats
 		for _, p := range pods {
@@ -163,7 +186,14 @@ func podStatsCmd(c *cliconfig.PodStatsValues) error {
 			outputJson(newStats)
 
 		} else {
-			outputToStdOut(newStats)
+			results := podContainerStatsToPodStatOut(newStats)
+			if len(format) == 0 {
+				outputToStdOut(results)
+			} else {
+				if err := printPSFormat(c.Format, results, headerNames); err != nil {
+					return err
+				}
+			}
 		}
 		time.Sleep(time.Second)
 		previousPodStats := new([]*libpod.PodContainerStats)
@@ -177,28 +207,88 @@ func podStatsCmd(c *cliconfig.PodStatsValues) error {
 	return nil
 }
 
-func outputToStdOut(stats []*libpod.PodContainerStats) {
-	outFormat := ("%-14s %-14s %-12s %-6s %-19s %-6s %-19s %-19s %-4s\n")
-	fmt.Printf(outFormat, "POD", "CID", "NAME", "CPU %", "MEM USAGE/ LIMIT", "MEM %", "NET IO", "BLOCK IO", "PIDS")
-	for _, i := range stats {
-		if len(i.ContainerStats) == 0 {
-			fmt.Printf(outFormat, i.Pod.ID()[:12], "--", "--", "--", "--", "--", "--", "--", "--")
-		}
-		for _, c := range i.ContainerStats {
-			cpu := floatToPercentString(c.CPU)
-			memUsage := combineHumanValues(c.MemUsage, c.MemLimit)
-			memPerc := floatToPercentString(c.MemPerc)
-			netIO := combineHumanValues(c.NetInput, c.NetOutput)
-			blockIO := combineHumanValues(c.BlockInput, c.BlockOutput)
-			pids := pidsToString(c.PIDs)
-			containerName := c.Name
-			if len(c.Name) > 10 {
-				containerName = containerName[:10]
+func podContainerStatsToPodStatOut(stats []*libpod.PodContainerStats) []*podStatOut {
+	var out []*podStatOut
+	for _, p := range stats {
+		for _, c := range p.ContainerStats {
+			o := podStatOut{
+				CPU:      floatToPercentString(c.CPU),
+				MemUsage: combineHumanValues(c.MemUsage, c.MemLimit),
+				Mem:      floatToPercentString(c.MemPerc),
+				NetIO:    combineHumanValues(c.NetInput, c.NetOutput),
+				BlockIO:  combineHumanValues(c.BlockInput, c.BlockOutput),
+				PIDS:     pidsToString(c.PIDs),
+				CID:      c.ContainerID[:12],
+				Name:     c.Name,
+				Pod:      p.Pod.ID()[:12],
 			}
-			fmt.Printf(outFormat, i.Pod.ID()[:12], c.ContainerID[:12], containerName, cpu, memUsage, memPerc, netIO, blockIO, pids)
+			out = append(out, &o)
+		}
+	}
+	return out
+}
+
+type podStatOut struct {
+	CPU      string
+	MemUsage string
+	Mem      string
+	NetIO    string
+	BlockIO  string
+	PIDS     string
+	Pod      string
+	CID      string
+	Name     string
+}
+
+func printPSFormat(format string, stats []*podStatOut, headerNames map[string]string) error {
+	if len(stats) == 0 {
+		return nil
+	}
+
+	// Use a tabwriter to align column format
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 3, ' ', 0)
+	// Spit out the header if "table" is present in the format
+	if strings.HasPrefix(format, "table") {
+		hformat := strings.Replace(strings.TrimSpace(format[5:]), " ", "\t", -1)
+		format = hformat
+		headerTmpl, err := template.New("header").Parse(hformat)
+		if err != nil {
+			return err
+		}
+		if err := headerTmpl.Execute(w, headerNames); err != nil {
+			return err
+		}
+		fmt.Fprintln(w, "")
+	}
+
+	// Spit out the data rows now
+	dataTmpl, err := template.New("data").Parse(format)
+	if err != nil {
+		return err
+	}
+	for _, container := range stats {
+		if err := dataTmpl.Execute(w, container); err != nil {
+			return err
+		}
+		fmt.Fprintln(w, "")
+	}
+	// Flush the writer
+	return w.Flush()
+
+}
+
+func outputToStdOut(stats []*podStatOut) {
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
+	outFormat := ("%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\n")
+	fmt.Fprintf(w, outFormat, "POD", "CID", "NAME", "CPU %", "MEM USAGE/ LIMIT", "MEM %", "NET IO", "BLOCK IO", "PIDS")
+	for _, i := range stats {
+		if len(stats) == 0 {
+			fmt.Fprintf(w, outFormat, i.Pod, "--", "--", "--", "--", "--", "--", "--", "--")
+		} else {
+			fmt.Fprintf(w, outFormat, i.Pod, i.CID, i.Name, i.CPU, i.MemUsage, i.Mem, i.NetIO, i.BlockIO, i.PIDS)
 		}
 	}
-	fmt.Println()
+	w.Flush()
 }
 
 func getPreviousPodContainerStats(podID string, prev []*libpod.PodContainerStats) map[string]*libpod.ContainerStats {
diff --git a/docs/podman-stats.1.md b/docs/podman-stats.1.md
index 8fc765326..d0b56b2e6 100644
--- a/docs/podman-stats.1.md
+++ b/docs/podman-stats.1.md
@@ -36,16 +36,17 @@ Valid placeholders for the Go template are listed below:
 
 | **Placeholder** | **Description**   |
 | --------------- | ---------------   |
-| .ID             | Container ID      |
+| .Pod            | Pod ID      |
+| .CID            | Container ID      |
 | .Name           | Container Name    |
-| .CPUPerc        | CPU percentage    |
+| .CPU            | CPU percentage    |
 | .MemUsage       | Memory usage      |
-| .MemPerc        | Memory percentage |
+| .Mem            | Memory percentage |
 | .NetIO          | Network IO        |
 | .BlockIO        | Block IO          |
 | .PIDS           | Number of PIDs    |
 
-
+When using a GO template, you may preceed the format with `table` to print headers.
 ## EXAMPLE
 
 ```
diff --git a/test/e2e/pod_stats_test.go b/test/e2e/pod_stats_test.go
index 43d089a24..e330c3a39 100644
--- a/test/e2e/pod_stats_test.go
+++ b/test/e2e/pod_stats_test.go
@@ -147,5 +147,28 @@ var _ = Describe("Podman pod stats", func() {
 		Expect(stats.ExitCode()).To(Equal(0))
 		Expect(stats.IsJSONOutputValid()).To(BeTrue())
 	})
+	It("podman stats with GO template", func() {
+		_, ec, podid := podmanTest.CreatePod("")
+		Expect(ec).To(Equal(0))
+
+		session := podmanTest.RunTopContainerInPod("", podid)
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		stats := podmanTest.Podman([]string{"pod", "stats", "-a", "--no-reset", "--no-stream", "--format", "\"table {{.CID}} {{.Pod}} {{.Mem}} {{.MemUsage}} {{.CPU}} {{.NetIO}} {{.BlockIO}} {{.PIDS}} {{.Pod}}\""})
+		stats.WaitWithDefaultTimeout()
+		Expect(stats.ExitCode()).To(Equal(0))
+	})
+
+	It("podman stats with invalid GO template", func() {
+		_, ec, podid := podmanTest.CreatePod("")
+		Expect(ec).To(Equal(0))
+
+		session := podmanTest.RunTopContainerInPod("", podid)
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		stats := podmanTest.Podman([]string{"pod", "stats", "-a", "--no-reset", "--no-stream", "--format", "\"table {{.ID}} \""})
+		stats.WaitWithDefaultTimeout()
+		Expect(stats.ExitCode()).ToNot(Equal(0))
+	})
 
 })