Fix podman stats based on QE feedback

QE found issues with formatting the go template and
the man page was lacking information.
Changed the format of the output to match latest docker.
Add shortID function that returns the truncated ID

Signed-off-by: umohnani8 <umohnani@redhat.com>

Closes: #258
Approved by: rhatdan

7 files changed, 75 insertions, 51 deletions

diff --git a/cmd/podman/common.go b/cmd/podman/common.go
index ae4bbd65d..921f30b84 100644
--- a/cmd/podman/common.go
+++ b/cmd/podman/common.go
@@ -22,7 +22,10 @@ var (
 	}
 )
 
-const crioConfigPath = "/etc/crio/crio.conf"
+const (
+	crioConfigPath = "/etc/crio/crio.conf"
+	idTruncLength  = 12
+)
 
 func getRuntime(c *cli.Context) (*libpod.Runtime, error) {
 
@@ -88,6 +91,13 @@ func splitCamelCase(src string) string {
 	return strings.Join(entries, " ")
 }
 
+func shortID(id string) string {
+	if len(id) > idTruncLength {
+		return id[:idTruncLength]
+	}
+	return id
+}
+
 // validateFlags searches for StringFlags or StringSlice flags that never had
 // a value set.  This commonly occurs when the CLI mistakenly takes the next
 // option and uses it as a value.
diff --git a/cmd/podman/history.go b/cmd/podman/history.go
index f142f5fd4..1164555d3 100644
--- a/cmd/podman/history.go
+++ b/cmd/podman/history.go
@@ -14,10 +14,7 @@ import (
 	"github.com/urfave/cli"
 )
 
-const (
-	createdByTruncLength = 45
-	idTruncLength        = 12
-)
+const createdByTruncLength = 45
 
 // historyTemplateParams stores info about each layer
 type historyTemplateParams struct {
@@ -169,7 +166,7 @@ func getHistoryTemplateOutput(history []v1.History, layers []types.BlobInfo, ima
 			imageID = "<missing>"
 		}
 		if !opts.noTrunc && i == len(history)-1 {
-			imageID = imageID[:idTruncLength]
+			imageID = shortID(imageID)
 		}
 
 		var size int64
diff --git a/cmd/podman/images.go b/cmd/podman/images.go
index 90dd8ae12..1f1174950 100644
--- a/cmd/podman/images.go
+++ b/cmd/podman/images.go
@@ -194,7 +194,7 @@ func getImagesTemplateOutput(runtime *libpod.Runtime, images []*storage.Image, o
 
 		imageID := "sha256:" + img.ID
 		if !opts.noTrunc {
-			imageID = img.ID[:idTruncLength]
+			imageID = shortID(img.ID)
 		}
 
 		repository := "<none>"
diff --git a/cmd/podman/ps.go b/cmd/podman/ps.go
index 0b75b9a96..e4c90187b 100644
--- a/cmd/podman/ps.go
+++ b/cmd/podman/ps.go
@@ -482,7 +482,7 @@ func getTemplateOutput(containers []*libpod.Container, opts psOptions) ([]psTemp
 		}
 
 		if !opts.noTrunc {
-			ctrID = ctr.ID()[:idTruncLength]
+			ctrID = shortID(ctr.ID())
 			imageName = conConfig.RootfsImageName
 		}
 
diff --git a/cmd/podman/stats.go b/cmd/podman/stats.go
index 871eb9e2f..21cca1d83 100644
--- a/cmd/podman/stats.go
+++ b/cmd/podman/stats.go
@@ -15,14 +15,14 @@ import (
 )
 
 type statsOutputParams struct {
-	Container string `json:"name"`
-	ID        string `json:"id"`
-	CPUPerc   string `json:"cpu_percent"`
-	MemUsage  string `json:"mem_usage"`
-	MemPerc   string `json:"mem_percent"`
-	NetIO     string `json:"netio"`
-	BlockIO   string `json:"blocki"`
-	PIDS      string `json:"pids"`
+	ID       string `json:"id"`
+	Name     string `json:"name"`
+	CPUPerc  string `json:"cpu_percent"`
+	MemUsage string `json:"mem_usage"`
+	MemPerc  string `json:"mem_percent"`
+	NetIO    string `json:"netio"`
+	BlockIO  string `json:"blocki"`
+	PIDS     string `json:"pids"`
 }
 
 var (
@@ -37,7 +37,7 @@ var (
 		},
 		cli.StringFlag{
 			Name:  "format",
-			Usage: "pretty-print container statistics using a Go template",
+			Usage: "pretty-print container statistics to JSON or using a Go template",
 		},
 		cli.BoolFlag{
 			Name:  "no-reset",
@@ -184,7 +184,12 @@ func outputStats(stats []*libpod.ContainerStats, format string) error {
 }
 
 func genStatsFormat() (format string) {
-	return "table {{.Container}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.MemPerc}}\t{{.NetIO}}\t{{.BlockIO}}\t{{.PIDS}}"
+	if format != "" {
+		// "\t" from the command line is not being recognized as a tab
+		// replacing the string "\t" to a tab character if the user passes in "\t"
+		return strings.Replace(format, `\t`, "\t", -1)
+	}
+	return "table {{.ID}}\t{{.Name}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.MemPerc}}\t{{.NetIO}}\t{{.BlockIO}}\t{{.PIDS}}"
 }
 
 // imagesToGeneric creates an empty array of interfaces for output
@@ -248,13 +253,13 @@ func pidsToString(pid uint64) string {
 
 func getStatsOutputParams(stats *libpod.ContainerStats) statsOutputParams {
 	return statsOutputParams{
-		Container: stats.ContainerID[:12],
-		ID:        stats.ContainerID,
-		CPUPerc:   floatToPercentString(stats.CPU),
-		MemUsage:  combineHumanValues(stats.MemUsage, stats.MemLimit),
-		MemPerc:   floatToPercentString(stats.MemPerc),
-		NetIO:     combineHumanValues(stats.NetInput, stats.NetOutput),
-		BlockIO:   combineHumanValues(stats.BlockInput, stats.BlockOutput),
-		PIDS:      pidsToString(stats.PIDs),
+		Name:     stats.Name,
+		ID:       shortID(stats.ContainerID),
+		CPUPerc:  floatToPercentString(stats.CPU),
+		MemUsage: combineHumanValues(stats.MemUsage, stats.MemLimit),
+		MemPerc:  floatToPercentString(stats.MemPerc),
+		NetIO:    combineHumanValues(stats.NetInput, stats.NetOutput),
+		BlockIO:  combineHumanValues(stats.BlockInput, stats.BlockOutput),
+		PIDS:     pidsToString(stats.PIDs),
 	}
 }
diff --git a/docs/podman-stats.1.md b/docs/podman-stats.1.md
index b071a27fa..7af14b8a6 100644
--- a/docs/podman-stats.1.md
+++ b/docs/podman-stats.1.md
@@ -31,48 +31,58 @@ Disable streaming stats and only pull the first result, default setting is false
 
 **--format="TEMPLATE"**
 
-Pretty-print images using a Go template
+Pretty-print container statistics to JSON or using a Go template
+
+Valid placeholders for the Go template are listed below:
+
+| **Placeholder** | **Description**   |
+| --------------- | ---------------   |
+| .ID             | Container ID      |
+| .Name           | Container Name    |
+| .CPUPerc        | CPU percentage    |
+| .MemUsage       | Memory usage      |
+| .MemPerc        | Memory percentage |
+| .NetIO          | Network IO        |
+| .BlockIO        | Block IO          |
+| .PIDS           | Number of PIDs    |
 
 
 ## EXAMPLE
 
 ```
 # podman stats -a --no-stream
-
-CONTAINER      CPU %   MEM USAGE / LIMIT   MEM %   NET IO    BLOCK IO       PIDS
-132ade621b5d   0.00%   1.618MB / 33.08GB   0.00%   0B / 0B   0B / 0B        0
-940e00a40a77   0.00%   1.544MB / 33.08GB   0.00%   0B / 0B   0B / 0B        0
-72a1dfb44ca7   0.00%   1.528MB / 33.08GB   0.00%   0B / 0B   0B / 0B        0
-f5a62a71b07b   0.00%   5.669MB / 33.08GB   0.02%   0B / 0B   0B / 0B        3
-31eab2cf93f4   0.00%   16.42MB / 33.08GB   0.05%   0B / 0B   22.43MB / 0B   0
-
-#
+ID             NAME              CPU %   MEM USAGE / LIMIT   MEM %   NET IO    BLOCK IO   PIDS
+a9f807ffaacd   frosty_hodgkin    --      3.092MB / 16.7GB    0.02%   -- / --   -- / --    2
+3b33001239ee   sleepy_stallman   --      -- / --             --      -- / --   -- / --    --
 ```
 
 ```
-# podman stats --no-stream 31eab2cf93f4
-CONTAINER      CPU %   MEM USAGE / LIMIT   MEM %   NET IO    BLOCK IO       PIDS
-31eab2cf93f4   0.00%   16.42MB / 33.08GB   0.05%   0B / 0B   22.43MB / 0B   0
-
-#
+# podman stats --no-stream a9f80
+ID             NAME             CPU %   MEM USAGE / LIMIT   MEM %   NET IO    BLOCK IO   PIDS
+a9f807ffaacd   frosty_hodgkin   --      3.092MB / 16.7GB    0.02%   -- / --   -- / --    2
 ```
+
 ```
-# podman stats --no-stream --format=json 31eab2cf93f4
+# podman stats --no-stream --format=json a9f80
 [
     {
-        "name": "31eab2cf93f4",
-        "id": "31eab2cf93f413af64a3f13d8d78393238658465d75e527333a8577f251162ec",
-        "cpu_percent": "0.00%",
-        "mem_usage": "16.42MB / 33.08GB",
-        "mem_percent": "0.05%",
-        "netio": "0B / 0B",
-        "blocki": "22.43MB / 0B",
-        "pids": 0
+        "id": "a9f807ffaacd",
+        "name": "frosty_hodgkin",
+        "cpu_percent": "--",
+        "mem_usage": "3.092MB / 16.7GB",
+        "mem_percent": "0.02%",
+        "netio": "-- / --",
+        "blocki": "-- / --",
+        "pids": "2"
     }
 ]
-#
 ```
 
+```
+# podman stats --no-stream --format "table {{.ID}} {{.Name}} {{.MemUsage}}" 6eae
+ID             NAME           MEM USAGE / LIMIT
+6eae9e25a564   clever_bassi   3.031MB / 16.7GB
+```
 
 ## SEE ALSO
 podman(1)
diff --git a/libpod/stats.go b/libpod/stats.go
index e87654277..47fb16194 100644
--- a/libpod/stats.go
+++ b/libpod/stats.go
@@ -13,6 +13,7 @@ import (
 // ContainerStats contains the statistics information for a running container
 type ContainerStats struct {
 	ContainerID string
+	Name        string
 	CPU         float64
 	CPUNano     uint64
 	SystemNano  uint64
@@ -30,6 +31,7 @@ type ContainerStats struct {
 func (c *Container) GetContainerStats(previousStats *ContainerStats) (*ContainerStats, error) {
 	stats := new(ContainerStats)
 	stats.ContainerID = c.ID()
+	stats.Name = c.Name()
 	c.lock.Lock()
 	defer c.lock.Unlock()
 	if err := c.syncContainer(); err != nil {