From a20bac35146a7c2e32f735b84ec14bf1b7f03e5f Mon Sep 17 00:00:00 2001
From: Peter Nickolov <peter@opsani.com>
Date: Tue, 21 Sep 2021 15:33:16 -0700
Subject: [PATCH] compute QoS & display

---
 app/model/model.go |  6 ++++++
 cmd/analysis.go    | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 cmd/output.go      |  5 +++--
 3 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/app/model/model.go b/app/model/model.go
index 5b28d5d..57db234 100644
--- a/app/model/model.go
+++ b/app/model/model.go
@@ -1,5 +1,11 @@
 package model
 
+const (
+	QOS_GUARANTEED = "guaranteed"
+	QOS_BURSTABLE  = "burstable"
+	QOS_BESTEFFORT = "besteffort"
+)
+
 type AppMetadata struct {
 	//Cluster string // needed?
 	//Name               string
diff --git a/cmd/analysis.go b/cmd/analysis.go
index 275ad5e..4ca164d 100644
--- a/cmd/analysis.go
+++ b/cmd/analysis.go
@@ -176,6 +176,50 @@ func analyzeContainers(app *appmodel.App) {
 	// TODO
 }
 
+func computePodQoS(app *appmodel.App) string {
+	// following the rules at https://kubernetes.io/docs/tasks/configure-pod-container/quality-service-pod/
+	// note: ignoring the init containers
+	// TODO: use other sources to get the QoS, use this one to (a) populate QoS if no QoS info found and
+	//       (b) validate the QoS found (e.g., degrade)
+
+	allMatch := true  // assume all containers, all resources match the guaranteed requirements
+	oneMatch := false // track if at least one container, one resource has resources specified
+	for i := range app.Containers {
+		c := &app.Containers[i]
+
+		if c.Cpu.Limit > 0 {
+			if c.Cpu.Request > 0 && c.Cpu.Request != c.Cpu.Limit {
+				allMatch = false
+			}
+			oneMatch = true
+		} else if c.Cpu.Request > 0 {
+			allMatch = false
+			oneMatch = true
+		} else {
+			allMatch = false
+		}
+		if c.Memory.Limit > 0 {
+			if c.Memory.Request > 0 && c.Memory.Request != c.Memory.Limit {
+				allMatch = false
+			}
+			oneMatch = true
+		} else if c.Memory.Request > 0 {
+			allMatch = false
+			oneMatch = true
+		} else {
+			allMatch = false
+		}
+	}
+
+	if allMatch {
+		return appmodel.QOS_GUARANTEED
+	} else if oneMatch {
+		return appmodel.QOS_BURSTABLE
+	} else {
+		return appmodel.QOS_BESTEFFORT
+	}
+}
+
 // --- App-level Analysis ----------------------------------------------------
 
 func preAnalyzeApp(app *appmodel.App) {
@@ -195,6 +239,14 @@ func preAnalyzeApp(app *appmodel.App) {
 			}
 		}
 	}
+
+	computedQos := computePodQoS(app)
+	if app.Settings.QosClass == "" {
+		app.Settings.QosClass = computedQos
+	} else if app.Settings.QosClass != computedQos {
+		log.Warnf("Computed QoS class %q does not match discovered QoS class %q for app %v; assuming the latter",
+			computedQos, app.Settings.QosClass, app.Metadata)
+	}
 }
 
 func analyzeApp(app *appmodel.App) {
diff --git a/cmd/output.go b/cmd/output.go
index cf58d6c..c049f39 100644
--- a/cmd/output.go
+++ b/cmd/output.go
@@ -81,7 +81,7 @@ func (table *AppTable) outputTableHeader() {
 	const RIGHT = tablewriter.ALIGN_RIGHT
 	const LEFT = tablewriter.ALIGN_LEFT
 
-	table.t.SetHeader([]string{"Rating", "Confidence", "Namespace", "Deployment", "Container", "Instances", "CPU", "Mem", "Reason"})
+	table.t.SetHeader([]string{"Rating", "Confidence", "Namespace", "Deployment", "QoS Class", "Instances", "CPU", "Mem", "Reason"})
 	table.t.SetColumnAlignment([]int{RIGHT, RIGHT, LEFT, LEFT, LEFT, RIGHT, RIGHT, RIGHT, LEFT})
 	table.t.SetFooter([]string{})
 	table.t.SetCenterSeparator("")
@@ -98,7 +98,7 @@ func (table *AppTable) outputTableApp(app *appmodel.App) {
 		fmt.Sprintf("%d%%", app.Analysis.Confidence),
 		app.Metadata.Namespace,
 		app.Metadata.Workload,
-		app.Analysis.MainContainer,
+		app.Settings.QosClass,
 		fmt.Sprintf("%.0fx%d", app.Metrics.AverageReplicas, len(app.Containers)),
 		fmt.Sprintf("%.0f%%", app.Metrics.CpuUtilization),
 		fmt.Sprintf("%.0f%%", app.Metrics.MemoryUtilization),
@@ -135,6 +135,7 @@ func (table *AppTable) outputDetailApp(app *appmodel.App) {
 	table.t.Rich([]string{"Deployment", app.Metadata.Workload}, nil)
 	table.t.Rich([]string{"Kind", fmt.Sprintf("%v (%v)", app.Metadata.WorkloadKind, app.Metadata.WorkloadApiVersion)}, nil)
 	table.t.Rich([]string{"Main Container", app.Analysis.MainContainer}, nil)
+	table.t.Rich([]string{"Pod QoS Class", app.Settings.QosClass}, nil)
 
 	table.t.Rich([]string{"Rating", fmt.Sprintf("%4d%%", app.Analysis.Rating)}, appColors)
 	table.t.Rich([]string{"Confidence", fmt.Sprintf("%4d%%", app.Analysis.Confidence)}, appColors)