Initial Attempt at JSON Support

pkg/capacity/json.go

@@ -0,0 +1,101 @@
+// Package capacity - json.go contains all the messy details for the json printer implementation
+package capacity
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+type jsonNodeMetric struct {
+	Name   string              `json:"name"`
+	CPU    *jsonResourceOutput `json:"cpu,omitempty"`
+	Memory *jsonResourceOutput `json:"memory,omitempty"`
+	Pods   []*jsonPod          `json:"pods,omitempty"`
+}
+
+type jsonPod struct {
+	Name      string              `json:"name"`
+	Namespace string              `json:"namespace"`
+	CPU       *jsonResourceOutput `json:"cpu"`
+	Memory    *jsonResourceOutput `json:"memory"`
+}
+
+type jsonResourceOutput struct {
+	Requests       string `json:"requests"`
+	RequestsPct    string `json:"requests_pct"`
+	Limits         string `json:"limits"`
+	LimitsPct      string `json:"limits_pct"`
+	Utilization    string `json:"utilization,omitempty"`
+	UtilizationPct string `json:"utilization_pct,omitempty"`
+}
+
+type jsonClusterMetrics struct {
+	Nodes         []*jsonNodeMetric `json:"nodes"`
+	ClusterTotals struct {
+		CPU    *jsonResourceOutput `json:"cpu"`
+		Memory *jsonResourceOutput `json:"memory"`
+	} `json:"cluster_totals"`
+}
+
+type jsonPrinter struct {
+	cm       *clusterMetric
+	showPods bool
+	showUtil bool
+}
+
+func (jp jsonPrinter) Print() {
+	jsonOutput := jp.buildJSONClusterMetrics()
+
+	jsonRaw, err := json.MarshalIndent(jsonOutput, "", "  ")
+	if err != nil {
+		fmt.Println("Error Marshalling JSON")
+		fmt.Println(err)
+	}
+
+	fmt.Printf("%s", jsonRaw)
+}
+
+func (jp *jsonPrinter) buildJSONClusterMetrics() jsonClusterMetrics {
+	var response jsonClusterMetrics
+
+	response.ClusterTotals.CPU = jp.buildJSONResourceOutput(jp.cm.cpu)
+	response.ClusterTotals.Memory = jp.buildJSONResourceOutput(jp.cm.memory)
+
+	for key, val := range jp.cm.nodeMetrics {
+		var node jsonNodeMetric
+		node.Name = key
+		node.CPU = jp.buildJSONResourceOutput(val.cpu)
+		node.Memory = jp.buildJSONResourceOutput(val.memory)
+		if jp.showPods {
+			for _, val := range val.podMetrics {
+				var newNode jsonPod
+				newNode.Name = val.name
+				newNode.Namespace = val.namespace
+				newNode.CPU = jp.buildJSONResourceOutput(val.cpu)
+				newNode.Memory = jp.buildJSONResourceOutput(val.memory)
+				node.Pods = append(node.Pods, &newNode)
+			}
+		}
+		response.Nodes = append(response.Nodes, &node)
+	}
+
+	return response
+}
+
+func (jp *jsonPrinter) buildJSONResourceOutput(item *resourceMetric) *jsonResourceOutput {
+	valueCalculator := item.valueFunction()
+	percentCalculator := item.percentFunction()
+
+	out := jsonResourceOutput{
+		Requests:    valueCalculator(item.request),
+		RequestsPct: percentCalculator(item.request),
+		Limits:      valueCalculator(item.limit),
+		LimitsPct:   percentCalculator(item.limit),
+	}
+
+	if jp.showUtil {
+		out.Utilization = valueCalculator(item.utilization)
+		out.UtilizationPct = percentCalculator(item.utilization)
+	}
+	return &out
+}

pkg/capacity/list.go

@@ -28,7 +28,7 @@ import (
 )
 
 // List gathers cluster resource data and outputs it
-func List(showPods, showUtil bool, podLabels, nodeLabels, namespaceLabels, kubeContext string) {
+func List(showPods, showUtil bool, podLabels, nodeLabels, namespaceLabels, kubeContext string, output string) {
 	clientset, err := kube.NewClientSet(kubeContext)
 	if err != nil {
 		fmt.Printf("Error connecting to Kubernetes: %v\n", err)
@@ -47,7 +47,7 @@ func List(showPods, showUtil bool, podLabels, nodeLabels, namespaceLabels, kubeC
 		pmList = getMetrics(mClientset)
 	}
 	cm := buildClusterMetric(podList, pmList, nodeList)
-	printList(&cm, showPods, showUtil)
+	printList(&cm, showPods, showUtil, output)
 }
 
 func getPodsAndNodes(clientset kubernetes.Interface, podLabels, nodeLabels, namespaceLabels string) (*corev1.PodList, *corev1.NodeList) {

pkg/capacity/printer.go

@@ -17,151 +17,56 @@ package capacity
 import (
 	"fmt"
 	"os"
-	"sort"
 	"text/tabwriter"
 )
 
-func printList(cm *clusterMetric, showPods bool, showUtil bool) {
-	names := make([]string, len(cm.nodeMetrics))
-
-	i := 0
-	for name := range cm.nodeMetrics {
-		names[i] = name
-		i++
-	}
-	sort.Strings(names)
-
-	w := new(tabwriter.Writer)
-	w.Init(os.Stdout, 0, 8, 2, ' ', 0)
-
-	printHeaders(w, cm, showPods, showUtil)
+const (
+	//TableOutput is the constant value for output type text
+	TableOutput string = "table"
+	//JSONOutput is the constant value for output type text
+	JSONOutput string = "json"
+)
 
-	for _, name := range names {
-		printNode(w, name, cm.nodeMetrics[name], showPods, showUtil)
+// SupportedOutputs returns a string list of output formats supposed by this package
+func SupportedOutputs() []string {
+	return []string{
+		TableOutput,
+		JSONOutput,
 	}
-
-	w.Flush()
 }
 
-func printHeaders(w *tabwriter.Writer, cm *clusterMetric, showPods bool, showUtil bool) {
-	if showPods && showUtil {
-		fmt.Fprintln(w, "NODE\t NAMESPACE\t POD\t CPU REQUESTS \t CPU LIMITS \t CPU UTIL \t MEMORY REQUESTS \t MEMORY LIMITS \t MEMORY UTIL")
-
-		if len(cm.nodeMetrics) > 1 {
-			fmt.Fprintf(w, "* \t *\t *\t %s \t %s \t %s \t %s \t %s \t %s \n",
-				cm.cpu.requestString(),
-				cm.cpu.limitString(),
-				cm.cpu.utilString(),
-				cm.memory.requestString(),
-				cm.memory.limitString(),
-				cm.memory.utilString())
-
-			fmt.Fprintln(w, "\t\t\t\t\t\t\t\t")
-		}
-	} else if showPods {
-		fmt.Fprintln(w, "NODE\t NAMESPACE\t POD\t CPU REQUESTS \t CPU LIMITS \t MEMORY REQUESTS \t MEMORY LIMITS")
-
-		fmt.Fprintf(w, "* \t *\t *\t %s \t %s \t %s \t %s \n",
-			cm.cpu.requestString(),
-			cm.cpu.limitString(),
-			cm.memory.requestString(),
-			cm.memory.limitString())
-
-		fmt.Fprintln(w, "\t\t\t\t\t\t")
-
-	} else if showUtil {
-		fmt.Fprintln(w, "NODE\t CPU REQUESTS \t CPU LIMITS \t CPU UTIL \t MEMORY REQUESTS \t MEMORY LIMITS \t MEMORY UTIL")
-
-		fmt.Fprintf(w, "* \t %s \t %s \t %s \t %s \t %s \t %s \n",
-			cm.cpu.requestString(),
-			cm.cpu.limitString(),
-			cm.cpu.utilString(),
-			cm.memory.requestString(),
-			cm.memory.limitString(),
-			cm.memory.utilString())
-
-	} else {
-		fmt.Fprintln(w, "NODE\t CPU REQUESTS \t CPU LIMITS \t MEMORY REQUESTS \t MEMORY LIMITS")
-
-		if len(cm.nodeMetrics) > 1 {
-			fmt.Fprintf(w, "* \t %s \t %s \t %s \t %s \n",
-				cm.cpu.requestString(), cm.cpu.limitString(),
-				cm.memory.requestString(), cm.memory.limitString())
-		}
-	}
+type printer interface {
+	Print()
 }
 
-func printNode(w *tabwriter.Writer, name string, nm *nodeMetric, showPods bool, showUtil bool) {
-	podNames := make([]string, len(nm.podMetrics))
-
-	i := 0
-	for name := range nm.podMetrics {
-		podNames[i] = name
-		i++
+func printList(cm *clusterMetric, showPods bool, showUtil bool, output string) {
+	p, err := printerFactory(cm, showPods, showUtil, output)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
 	}
-	sort.Strings(podNames)
-
-	if showPods && showUtil {
-		fmt.Fprintf(w, "%s \t *\t *\t %s \t %s \t %s \t %s \t %s \t %s \n",
-			name,
-			nm.cpu.requestString(),
-			nm.cpu.limitString(),
-			nm.cpu.utilString(),
-			nm.memory.requestString(),
-			nm.memory.limitString(),
-			nm.memory.utilString())
+	p.Print()
+}
 
-		for _, podName := range podNames {
-			pm := nm.podMetrics[podName]
-			fmt.Fprintf(w, "%s \t %s \t %s \t %s \t %s \t %s \t %s \t %s \t %s \n",
-				name,
-				pm.namespace,
-				pm.name,
-				pm.cpu.requestString(),
-				pm.cpu.limitString(),
-				pm.cpu.utilString(),
-				pm.memory.requestString(),
-				pm.memory.limitString(),
-				pm.memory.utilString())
+func printerFactory(cm *clusterMetric, showPods bool, showUtil bool, outputType string) (printer, error) {
+	var response printer
+	switch outputType {
+	case JSONOutput:
+		response = jsonPrinter{
+			cm:       cm,
+			showPods: showPods,
+			showUtil: showUtil,
 		}
-
-		fmt.Fprintln(w, "\t\t\t\t\t\t\t\t")
-
-	} else if showPods {
-		fmt.Fprintf(w, "%s \t *\t *\t %s \t %s \t %s \t %s \n",
-			name,
-			nm.cpu.requestString(),
-			nm.cpu.limitString(),
-			nm.memory.requestString(),
-			nm.memory.limitString())
-
-		for _, podName := range podNames {
-			pm := nm.podMetrics[podName]
-			fmt.Fprintf(w, "%s \t %s \t %s \t %s \t %s \t %s \t %s \n",
-				name,
-				pm.namespace,
-				pm.name,
-				pm.cpu.requestString(),
-				pm.cpu.limitString(),
-				pm.memory.requestString(),
-				pm.memory.limitString())
+		return response, nil
+	case TableOutput:
+		response = tablePrinter{
+			cm:       cm,
+			showPods: showPods,
+			showUtil: showUtil,
+			w:        new(tabwriter.Writer),
 		}
-
-		fmt.Fprintln(w, "\t\t\t\t\t\t")
-
-	} else if showUtil {
-		fmt.Fprintf(w, "%s \t %s \t %s \t %s \t %s \t %s \t %s \n",
-			name,
-			nm.cpu.requestString(),
-			nm.cpu.limitString(),
-			nm.cpu.utilString(),
-			nm.memory.requestString(),
-			nm.memory.limitString(),
-			nm.memory.utilString())
-
-	} else {
-		fmt.Fprintf(w, "%s \t %s \t %s \t %s \t %s \n", name,
-			nm.cpu.requestString(), nm.cpu.limitString(),
-			nm.memory.requestString(), nm.memory.limitString())
+		return response, nil
+	default:
+		return response, fmt.Errorf("Called with an unsupported output type: %s", outputType)
 	}
 }

pkg/capacity/resources.go

@@ -18,9 +18,9 @@ import (
 	"fmt"
 
 	corev1 "k8s.io/api/core/v1"
-	v1beta1 "k8s.io/metrics/pkg/apis/metrics/v1beta1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	resourcehelper "k8s.io/kubernetes/pkg/kubectl/util/resource"
+	v1beta1 "k8s.io/metrics/pkg/apis/metrics/v1beta1"
 )
 
 type resourceMetric struct {
@@ -138,3 +138,26 @@ func resourceString(actual, allocatable resource.Quantity, resourceType string)
 	}
 	return fmt.Sprintf("%dMi (%d%%)", actual.Value()/1048576, int64(utilPercent))
 }
+
+// NOTE: This might not be a great place for closures due to the cyclical nature of how resourceType works. Perhaps better implemented another way.
+func (rm resourceMetric) valueFunction() (f func(r resource.Quantity) string) {
+	switch rm.resourceType {
+	case "cpu":
+		f = func(r resource.Quantity) string {
+			return fmt.Sprintf("%dm", r.MilliValue())
+		}
+	case "memory":
+		f = func(r resource.Quantity) string {
+			return fmt.Sprintf("%dMi", r.Value()/1048576)
+		}
+	}
+	return f
+}
+
+// NOTE: This might not be a great place for closures due to the cyclical nature of how resourceType works. Perhaps better implemented another way.
+func (rm resourceMetric) percentFunction() (f func(r resource.Quantity) string) {
+	f = func(r resource.Quantity) string {
+		return fmt.Sprintf("%v%%", int64(float64(r.MilliValue())/float64(rm.allocatable.MilliValue())*100))
+	}
+	return f
+}