Use instance requirements to get a wider set of instance types by default

tests/integration/create_cluster/karpenter/expected-v1alpha2.yaml

@@ -110,6 +110,12 @@ spec:
   manager: Karpenter
   maxSize: 2
   minSize: 2
+  mixedInstancesPolicy:
+    instanceRequirements:
+      cpu:
+        min: "2"
+      memory:
+        min: 2G
   nodeLabels:
     kops.k8s.io/instancegroup: nodes
   role: Node

upup/pkg/fi/cloudup/new_cluster.go

@@ -876,6 +876,24 @@ func setupKarpenterNodes(opt *NewClusterOptions, cluster *api.Cluster, zoneToSub
 		HTTPTokens:              fi.String("required"),
 	}
 
+	// Karpenter thinks all clusters run VPC CNI and schedules thinking Node Capacity is constrainted by number of ENIs.
+
+	// cpuMin is the reasonable lower limit for a Kubernetes Node
+	// Generally, it also avoids instances Karpenter thinks it can only schedule 4 Pods on.
+	cpuMin := resource.MustParse("2")
+	memoryMin := resource.MustParse(("2G"))
+
+	g.Spec.MixedInstancesPolicy = &api.MixedInstancesPolicySpec{
+		InstanceRequirements: &api.InstanceRequirementsSpec{
+			CPU: &api.MinMaxSpec{
+				Min: &cpuMin,
+			},
+			Memory: &api.MinMaxSpec{
+				Min: &memoryMin,
+			},
+		},
+	}
+
 	return []*api.InstanceGroup{g}, nil
 }
 

upup/pkg/fi/cloudup/template_functions.go

@@ -822,6 +822,13 @@ func karpenterInstanceTypes(cloud awsup.AWSCloud, ig kops.InstanceGroupSpec) ([]
 			ir := &ec2.InstanceRequirementsRequest{
 				VCpuCount:            &ec2.VCpuCountRangeRequest{},
 				MemoryMiB:            &ec2.MemoryMiBRequest{},
+				BurstablePerformance: fi.String("included"),
+			}
+			cpu := instanceRequirements.CPU
+			if cpu != nil {
+				if cpu.Max != nil {
+					cpuMax, _ := instanceRequirements.CPU.Max.AsInt64()
+					ir.VCpuCount.Max = &cpuMax
 				}
 				cpu := instanceRequirements.CPU
 				if cpu != nil {
@@ -876,5 +883,6 @@ func karpenterInstanceTypes(cloud awsup.AWSCloud, ig kops.InstanceGroupSpec) ([]
 				return types, nil
 			}
 		}
+	}
 	return []string{ig.MachineType}, nil
 }