feat(api): Add kubernetes version to coredns version mapping (#939)

Added script and makefile target to update coredns version mapping.
`make coredns.sync` will fetch the list of releases from upstream
release branches and create a mapping of k8s versions to coredns
versions.

.pre-commit-config.yaml

@@ -63,6 +63,11 @@ repos:
     language: system
     files: "^devbox.(yaml|lock)$"
     pass_filenames: false
+  - id: check-coredns-versions
+    name: check-coredns-versions
+    entry: make coredns.sync
+    language: system
+    files: "^api/versions/coredns.go$"
 - repo: https://github.com/tekwizely/pre-commit-golang
   rev: v1.0.0-rc.1
   hooks:

api/go.mod

@@ -11,9 +11,11 @@ replace github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/c
 
 require (
 	github.com/aws/aws-sdk-go v1.55.5
+	github.com/blang/semver/v4 v4.0.0
 	github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/common v0.7.0
 	github.com/nutanix-cloud-native/prism-go-client v0.5.1
 	github.com/onsi/gomega v1.34.2
+	github.com/stretchr/testify v1.9.0
 	k8s.io/api v0.30.5
 	k8s.io/apiextensions-apiserver v0.30.5
 	k8s.io/apimachinery v0.30.5
@@ -24,7 +26,6 @@ require (
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
-	github.com/blang/semver/v4 v4.0.0 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/emicklei/go-restful/v3 v3.12.1 // indirect
@@ -51,6 +52,7 @@ require (
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_golang v1.18.0 // indirect
 	github.com/prometheus/client_model v0.6.0 // indirect
 	github.com/prometheus/common v0.45.0 // indirect

api/versions/coredns_test.go

@@ -0,0 +1,51 @@
+// Copyright 2024 Nutanix. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package versions
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReturnsCorrectCoreDNSVersionForValidKubernetesVersion(t *testing.T) {
+	version, found := GetCoreDNSVersion("v1.27")
+	assert.True(t, found)
+	assert.Equal(t, "v1.10.1", version)
+}
+
+func TestReturnsCorrectCoreDNSVersionForValidKubernetesVersionWithoutVPrefix(t *testing.T) {
+	version, found := GetCoreDNSVersion("1.27")
+	assert.True(t, found)
+	assert.Equal(t, "v1.10.1", version)
+}
+
+func TestReturnsFalseForInvalidKubernetesVersion(t *testing.T) {
+	version, found := GetCoreDNSVersion("v2.99")
+	assert.False(t, found)
+	assert.Equal(t, "", version)
+}
+
+func TestReturnsFalseForMalformedKubernetesVersion(t *testing.T) {
+	version, found := GetCoreDNSVersion("invalid-version")
+	assert.False(t, found)
+	assert.Equal(t, "", version)
+}
+
+func TestReturnsCorrectMappingForGetKubernetesToCoreDNSVersionMap(t *testing.T) {
+	mapping := GetKubernetesToCoreDNSVersionMap()
+	expected := map[string]string{
+		"v1.22": "v1.8.4",
+		"v1.23": "v1.8.6",
+		"v1.24": "v1.8.6",
+		"v1.25": "v1.9.3",
+		"v1.26": "v1.9.3",
+		"v1.27": "v1.10.1",
+		"v1.28": "v1.10.1",
+		"v1.29": "v1.11.1",
+		"v1.30": "v1.11.3",
+		"v1.31": "v1.11.3",
+	}
+	assert.Equal(t, expected, mapping)
+}