fix: print the correct field path when spec.api.publicName is missing

We introduce a field-mapping layer to help us map v1alpha2 -> v1alpha3 and vice-versa

pkg/apis/kops/fieldmap.go

@@ -0,0 +1,71 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kops
+
+// Because we have multiple versions of the API, fields hvae different paths in different API versions.
+// This file contains the mappings from the old paths to the new paths.
+
+// These functions are somewhat of a work in progress, we are adding function mappings as we hit them.
+
+// HumanPathForClusterField returns the path for a given v1alpha3 cluster field, as we should print it for users.
+func HumanPathForClusterField(fieldPath string) string {
+	f := NewClusterField(fieldPath)
+	return f.HumanPath()
+}
+
+// ClusterField represents a field in the Cluster resource.
+type ClusterField struct {
+	Path string
+}
+
+// NewClusterField creates a new ClusterField for the given path.
+func NewClusterField(path string) *ClusterField {
+	return &ClusterField{Path: path}
+}
+
+// HumanPath returns the path for the field, as we should print it for users.
+func (f *ClusterField) HumanPath() string {
+	return f.PathInV1Alpha2()
+}
+
+// PathInV1Alpha2 returns the path for the field in the v1alpha2 API.
+func (f *ClusterField) PathInV1Alpha2() string {
+	for _, mapping := range clusterFieldMappings {
+		if mapping.V1Alpha3 == f.Path {
+			return mapping.V1Alpha2
+		}
+	}
+	return f.Path
+}
+
+// PathInV1Alpha3 returns the path for the field in the v1alpha3 API.
+func (f *ClusterField) PathInV1Alpha3() string {
+	for _, mapping := range clusterFieldMappings {
+		if mapping.V1Alpha2 == f.Path {
+			return mapping.V1Alpha3
+		}
+	}
+	return f.Path
+}
+
+// clusterFieldMappings is a list of mappings from v1alpha2 field paths to v1alpha3 field paths.
+var clusterFieldMappings = []struct {
+	V1Alpha2 string
+	V1Alpha3 string
+}{
+	{V1Alpha2: "spec.masterPublicName", V1Alpha3: "spec.api.publicName"},
+}

pkg/apis/kops/fieldmap_test.go

@@ -0,0 +1,20 @@
+package kops
+
+import "testing"
+
+func TestClusterFieldHumanPath(t *testing.T) {
+	grid := []struct {
+		In       string
+		Expected string
+	}{
+		{In: "spec.api.publicName", Expected: "spec.masterPublicName"},
+		{In: "spec.api", Expected: "spec.api"},
+	}
+
+	for _, g := range grid {
+		actual := HumanPathForClusterField(g.In)
+		if actual != g.Expected {
+			t.Errorf("HumanPathForClusterField(%q) = %q; expected %q", g.In, actual, g.Expected)
+		}
+	}
+}

upup/pkg/fi/cloudup/metal/cloud.go

@@ -100,7 +100,7 @@ func (c *Cloud) GetApiIngressStatus(cluster *kops.Cluster) ([]fi.ApiIngressStatu
 	var ret []fi.ApiIngressStatus
 	publicName := cluster.Spec.API.PublicName
 	if publicName == "" {
-		return ret, fmt.Errorf("spec.api.publicName must be set for bare metal")
+		return ret, fmt.Errorf("%s must be set for bare metal", kops.HumanPathForClusterField("spec.api.publicName"))
 	}
 	ip := net.ParseIP(publicName)
 	if ip == nil {