Add color to hpa line when replicas >= maxpods (#2333)

* feat: paint hpa line when replicas >= maxpods

* chore: add license headers

* refactor: decrease Assignment Branch Condition

* validate IndexOf returns a valid index

internal/model/registry.go

@@ -202,4 +202,14 @@ var Registry = map[string]ResourceMeta{
 	"rbac.authorization.k8s.io/v1/rolebindings": {
 		Renderer: &render.RoleBinding{},
 	},
+
+	// Autoscaling...
+	"autoscaling/v1/horizontalpodautoscalers": {
+		Renderer: &render.HorizontalPodAutoscaler{},
+		DAO:      &dao.Table{},
+	},
+	"autoscaling/v2/horizontalpodautoscalers": {
+		Renderer: &render.HorizontalPodAutoscaler{},
+		DAO:      &dao.Table{},
+	},
 }

internal/render/hpa.go

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Authors of K9s
+
+package render
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/derailed/tcell/v2"
+)
+
+// HorizontalPodAutoscaler renders a K8s HorizontalPodAutoscaler to screen.
+type HorizontalPodAutoscaler struct {
+	Generic
+}
+
+// ColorerFunc colors a resource row.
+func (hpa HorizontalPodAutoscaler) ColorerFunc() ColorerFunc {
+	return func(ns string, h Header, re RowEvent) tcell.Color {
+		c := DefaultColorer(ns, h, re)
+
+		maxPodsIndex := h.IndexOf("MAXPODS", true)
+		replicasIndex := h.IndexOf("REPLICAS", true)
+		if (maxPodsIndex < 0 || maxPodsIndex >= len(re.Row.Fields)) || (replicasIndex < 0 || replicasIndex >= len(re.Row.Fields)) {
+			return c
+		}
+
+		maxPodsS := strings.TrimSpace(re.Row.Fields[maxPodsIndex])
+		currentReplicasS := strings.TrimSpace(re.Row.Fields[replicasIndex])
+
+		maxPods, err := strconv.Atoi(maxPodsS)
+		if err != nil {
+			return c
+		}
+		currentReplicas, err := strconv.Atoi(currentReplicasS)
+		if err != nil {
+			return c
+		}
+		if currentReplicas >= maxPods {
+			c = ErrColor
+		}
+		return c
+	}
+}

internal/render/hpa_test.go

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Authors of K9s
+
+package render
+
+import (
+	"testing"
+
+	"github.com/derailed/tcell/v2"
+	"github.com/derailed/tview"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHorizontalPodAutoscalerColorer(t *testing.T) {
+	hpaHeader := Header{
+		HeaderColumn{Name: "NAMESPACE"},
+		HeaderColumn{Name: "NAME"},
+		HeaderColumn{Name: "REFERENCE"},
+		HeaderColumn{Name: "TARGETS%"},
+		HeaderColumn{Name: "MINPODS", Align: tview.AlignRight},
+		HeaderColumn{Name: "MAXPODS", Align: tview.AlignRight},
+		HeaderColumn{Name: "REPLICAS", Align: tview.AlignRight},
+		HeaderColumn{Name: "AGE", Time: true},
+	}
+
+	uu := map[string]struct {
+		h  Header
+		re RowEvent
+		e  tcell.Color
+	}{
+		"when replicas = maxpods": {
+			h: hpaHeader,
+			re: RowEvent{
+				Kind: EventUnchanged,
+				Row: Row{
+					Fields: Fields{"blee", "fred", "fred", "100%", "1", "5", "5", "1d"},
+				},
+			},
+			e: ErrColor,
+		},
+		"when replicas > maxpods, for some reason": {
+			h: hpaHeader,
+			re: RowEvent{
+				Kind: EventUnchanged,
+				Row: Row{
+					Fields: Fields{"blee", "fred", "fred", "100%", "1", "5", "6", "1d"},
+				},
+			},
+			e: ErrColor,
+		},
+		"when replicas < maxpods": {
+			h: hpaHeader,
+			re: RowEvent{
+				Kind: EventUnchanged,
+				Row: Row{
+					Fields: Fields{"blee", "fred", "fred", "100%", "1", "5", "1", "1d"},
+				},
+			},
+			e: StdColor,
+		},
+	}
+
+	var r HorizontalPodAutoscaler
+	for k := range uu {
+		u := uu[k]
+		t.Run(k, func(t *testing.T) {
+			assert.Equal(t, u.e, r.ColorerFunc()("", u.h, u.re))
+		})
+	}
+}