Modify the JSON output of kpod ps

Changed the JSON output to hold the actual type of the data.
For example the creation time of a container will be of form time.Time.
The human readable output modifies all the fields to type string, which
is not helpful when the JSON output wants to be used for further processing.

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

cmd/kpod/ps.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"fmt"
 	"reflect"
 	"regexp"
 	"strconv"
@@ -33,18 +32,37 @@ type psOptions struct {
 	label   string
 }
 
-type psOutputParams struct {
+type psTemplateParams struct {
-	ID         string `json:"id"`
+	ID         string
-	Image      string `json:"image"`
+	Image      string
-	Command    string `json:"command"`
+	Command    string
-	CreatedAt  string `json:"created"`
+	CreatedAt  string
-	RunningFor string `json:"running"`
+	RunningFor string
-	Status     string `json:"status"`
+	Status     string
-	Ports      string `json:"ports"`
+	Ports      string
-	Size       string `json:"size"`
+	Size       string
-	Names      string `json:"names"`
+	Names      string
-	Labels     string `json:"labels"`
+	Labels     string
-	Mounts     string `json:"mounts"`
+	Mounts     string
+}
+
+// psJSONParams is only used when the JSON format is specified,
+// and is better for data processing from JSON.
+// psJSONParams will be populated by data from libkpod.ContainerData,
+// the members of the struct are the sama data types as their sources.
+type psJSONParams struct {
+	ID               string              `json:"id"`
+	Image            string              `json:"image"`
+	Command          string              `json:"command"`
+	CreatedAt        time.Time           `json:"createdAt"`
+	RunningFor       time.Duration       `json:"runningFor"`
+	Status           string              `json:"status"`
+	Ports            map[string]struct{} `json:"ports"`
+	Size             uint                `json:"size"`
+	Names            string              `json:"names"`
+	Labels           fields.Set          `json:"labels"`
+	Mounts           []specs.Mount       `json:"mounts"`
+	ContainerRunning bool                `json:"ctrRunning"`
 }
 
 const runningState = "running"
@@ -159,7 +177,7 @@ func psCmd(c *cli.Context) error {
 
 	containerList := getContainersMatchingFilter(containers, params, server)
 
-	return psOutput(containerList, server, opts)
+	return generatePsOutput(containerList, server, opts)
 }
 
 // generate the template based on conditions given
@@ -174,16 +192,21 @@ func genPsFormat(quiet, size bool) (format string) {
 	return
 }
 
-func psToGeneric(params []psOutputParams) []interface{} {
+func psToGeneric(templParams []psTemplateParams, JSONParams []psJSONParams) (genericParams []interface{}) {
-	genericParams := make([]interface{}, len(params))
+	if len(templParams) > 0 {
-	for i, v := range params {
+		for _, v := range templParams {
-		genericParams[i] = interface{}(v)
+			genericParams = append(genericParams, interface{}(v))
+		}
+		return
 	}
-	return genericParams
+	for _, v := range JSONParams {
+		genericParams = append(genericParams, interface{}(v))
+	}
+	return
 }
 
 // generate the accurate header based on template given
-func (p *psOutputParams) headerMap() map[string]string {
+func (p *psTemplateParams) headerMap() map[string]string {
 	v := reflect.Indirect(reflect.ValueOf(p))
 	values := make(map[string]string)
 
@@ -221,38 +244,19 @@ func getContainers(containers []*libkpod.ContainerData, opts psOptions) []*libkp
 	return containersOutput
 }
 
-func psOutput(containers []*libkpod.ContainerData, server *libkpod.ContainerServer, opts psOptions) error {
+// getTemplateOutput returns the modified container information
-	var (
+func getTemplateOutput(containers []*libkpod.ContainerData, opts psOptions) (psOutput []psTemplateParams) {
-		output           []psOutputParams
+	var status string
-		containersOutput []*libkpod.ContainerData
+	for _, ctr := range containers {
-		status           string
+		ctrID := ctr.ID
-		ctrID            string
+		runningFor := units.HumanDuration(time.Since(ctr.State.Created))
-		command          string
+		createdAt := runningFor + " ago"
-		runningFor       string
+		command := getCommand(ctr.ImageCreatedBy)
-		imageName        string
+		imageName := ctr.FromImage
-		mounts           string
+		mounts := getMounts(ctr.Mounts, opts.noTrunc)
-		ports            string
+		ports := getPorts(ctr.Config.ExposedPorts)
-		size             string
+		size := units.HumanSize(float64(ctr.SizeRootFs))
-		labels           string
+		labels := getLabels(ctr.Labels)
-		createdAt        string
-	)
-
-	if len(containers) == 0 {
-		fmt.Println("hereee")
-		return nil
-	}
-	containersOutput = getContainers(containers, opts)
-
-	for _, ctr := range containersOutput {
-		ctrID = ctr.ID
-		runningFor = units.HumanDuration(time.Since(ctr.State.Created))
-		createdAt = runningFor + " ago"
-		command = getCommand(ctr.ImageCreatedBy)
-		imageName = ctr.FromImage
-		mounts = getMounts(ctr.Mounts, opts.noTrunc)
-		ports = getPorts(ctr.Config.ExposedPorts)
-		size = units.HumanSize(float64(ctr.SizeRootFs))
-		labels = getLabels(ctr.Labels)
 
 		switch ctr.State.Status {
 		case "stopped":
@@ -268,7 +272,7 @@ func psOutput(containers []*libkpod.ContainerData, server *libkpod.ContainerServ
 			imageName = getImageName(ctr.FromImage)
 		}
 
-		params := psOutputParams{
+		params := psTemplateParams{
 			ID:         ctrID,
 			Image:      imageName,
 			Command:    command,
@@ -281,10 +285,36 @@ func psOutput(containers []*libkpod.ContainerData, server *libkpod.ContainerServ
 			Labels:     labels,
 			Mounts:     mounts,
 		}
-		output = append(output, params)
+		psOutput = append(psOutput, params)
 	}
+	return
+}
 
-	if len(output) == 0 {
+// getJSONOutput returns the container info in its raw form
+func getJSONOutput(containers []*libkpod.ContainerData) (psOutput []psJSONParams) {
+	for _, ctr := range containers {
+		params := psJSONParams{
+			ID:               ctr.ID,
+			Image:            ctr.FromImage,
+			Command:          ctr.ImageCreatedBy,
+			CreatedAt:        ctr.State.Created,
+			RunningFor:       time.Since(ctr.State.Created),
+			Status:           ctr.State.Status,
+			Ports:            ctr.Config.ExposedPorts,
+			Size:             ctr.SizeRootFs,
+			Names:            ctr.Name,
+			Labels:           ctr.Labels,
+			Mounts:           ctr.Mounts,
+			ContainerRunning: ctr.State.Status == runningState,
+		}
+		psOutput = append(psOutput, params)
+	}
+	return
+}
+
+func generatePsOutput(containers []*libkpod.ContainerData, server *libkpod.ContainerServer, opts psOptions) error {
+	containersOutput := getContainers(containers, opts)
+	if len(containersOutput) == 0 {
 		return nil
 	}
 
@@ -292,9 +322,11 @@ func psOutput(containers []*libkpod.ContainerData, server *libkpod.ContainerServ
 
 	switch opts.format {
 	case formats.JSONString:
-		out = formats.JSONStructArray{Output: psToGeneric(output)}
+		psOutput := getJSONOutput(containersOutput)
+		out = formats.JSONStructArray{Output: psToGeneric([]psTemplateParams{}, psOutput)}
 	default:
-		out = formats.StdoutTemplateArray{Output: psToGeneric(output), Template: opts.format, Fields: output[0].headerMap()}
+		psOutput := getTemplateOutput(containersOutput, opts)
+		out = formats.StdoutTemplateArray{Output: psToGeneric(psOutput, []psJSONParams{}), Template: opts.format, Fields: psOutput[0].headerMap()}
 	}
 
 	return formats.Writer(out).Out()