Implement DaemonSet history logic in controller

1. Create controllerrevisions (history) and label pods with template
   hash for both RollingUpdate and OnDelete update strategy
2. Clean up old, non-live history based on revisionHistoryLimit
3. Remove duplicate controllerrevisions (the ones with the same template)
   and relabel their pods
4. Update RBAC to allow DaemonSet controller to manage
   controllerrevisions
5. In DaemonSet controller unit tests, create new pods with hash labels

pkg/controller/controller_utils_test.go

@@ -19,6 +19,7 @@ package controller
 import (
 	"encoding/json"
 	"fmt"
+	"math"
 	"math/rand"
 	"net/http/httptest"
 	"reflect"
@@ -443,3 +444,38 @@ func TestActiveReplicaSetsFiltering(t *testing.T) {
 		t.Errorf("expected %v, got %v", expectedNames.List(), gotNames.List())
 	}
 }
+
+func int64P(num int64) *int64 {
+	return &num
+}
+
+func TestComputeHash(t *testing.T) {
+	tests := []struct {
+		name                string
+		template            *v1.PodTemplateSpec
+		collisionCount      *int64
+		otherCollisionCount *int64
+	}{
+		{
+			name:                "simple",
+			template:            &v1.PodTemplateSpec{},
+			collisionCount:      int64P(1),
+			otherCollisionCount: int64P(2),
+		},
+		{
+			name:                "using math.MaxInt64",
+			template:            &v1.PodTemplateSpec{},
+			collisionCount:      nil,
+			otherCollisionCount: int64P(int64(math.MaxInt64)),
+		},
+	}
+
+	for _, test := range tests {
+		hash := ComputeHash(test.template, test.collisionCount)
+		otherHash := ComputeHash(test.template, test.otherCollisionCount)
+
+		if hash == otherHash {
+			t.Errorf("expected different hashes but got the same: %d", hash)
+		}
+	}
+}