feat(upgrade_to_v3): add migration warnings for metrics-server changes

src/go/cmd/update-collection-v3/main.go

@@ -14,6 +14,7 @@ import (
 	kubestatemetricscollectors "github.com/SumoLogic/sumologic-kubernetes-collection/tools/cmd/update-collection-v3/migrations/kube-state-metrics-collectors"
 	"github.com/SumoLogic/sumologic-kubernetes-collection/tools/cmd/update-collection-v3/migrations/logsmetadataconfig"
 	metricsmetadataconfig "github.com/SumoLogic/sumologic-kubernetes-collection/tools/cmd/update-collection-v3/migrations/metrics-metadata-config"
+	metricsserverupgrade "github.com/SumoLogic/sumologic-kubernetes-collection/tools/cmd/update-collection-v3/migrations/metrics-server-upgrade"
 	otellogsconfigmerge "github.com/SumoLogic/sumologic-kubernetes-collection/tools/cmd/update-collection-v3/migrations/otellogs-config-merge"
 	removeloadconfigfile "github.com/SumoLogic/sumologic-kubernetes-collection/tools/cmd/update-collection-v3/migrations/remove-load-config-file"
 	tracingreplaces "github.com/SumoLogic/sumologic-kubernetes-collection/tools/cmd/update-collection-v3/migrations/tracing-replaces"
@@ -101,6 +102,10 @@ var migrations = []Migration{
 		directory: "otellogs-config-merge",
 		action:    otellogsconfigmerge.Migrate,
 	},
+	{
+		directory: "metrics-server-upgrade",
+		action:    metricsserverupgrade.Migrate,
+	},
 }
 
 func migrateYaml(input string) (string, error) {

src/go/cmd/update-collection-v3/migrations/metrics-server-upgrade/migrate.go

@@ -0,0 +1,54 @@
+package metricsserverupgrade
+
+import (
+	"fmt"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Values struct {
+	MetricsServer struct {
+		Rest map[string]interface{} `yaml:",inline"`
+	} `yaml:"kube-prometheus-stack,omitempty"`
+	Rest map[string]interface{} `yaml:",inline"`
+}
+
+func Migrate(inputYaml string) (outputYaml string, err error) {
+	values, err := parseValues(inputYaml)
+	if err != nil {
+		return "", fmt.Errorf("error parsing input yaml: %v", err)
+	}
+
+	values = migrate(&values)
+	if err != nil {
+		return "", fmt.Errorf("error migrating: %v", err)
+	}
+
+	return inputYaml, nil
+}
+
+func parseValues(inputYaml string) (Values, error) {
+	var v Values
+	err := yaml.Unmarshal([]byte(inputYaml), &v)
+	return v, err
+}
+
+func migrate(values *Values) Values {
+	log := migrateLog(values)
+
+	if log != "" {
+		fmt.Println(log)
+	}
+
+	return *values
+}
+
+func migrateLog(values *Values) string {
+	if len(values.MetricsServer.Rest) == 0 {
+		return ""
+	}
+
+	return "WARNING! Changes in metrics-server detected, which may require manual migration\n" +
+		"For details please see the following documentations:\n  - https://github.com/SumoLogic/sumologic-kubernetes-collection/blob/main/docs/v3-migration-doc.md\n" +
+		"  - https://github.com/bitnami/charts/tree/5b09f7a7c0d9232f5752840b6c4e5cdc56d7f796/bitnami/metrics-server#to-600"
+}

src/go/cmd/update-collection-v3/migrations/metrics-server-upgrade/migrate_test.go

@@ -0,0 +1,47 @@
+package metricsserverupgrade
+
+import (
+	"testing"
+
+	"gotest.tools/assert"
+)
+
+var (
+	foo interface{} = "bar"
+)
+
+func TestMain(t *testing.T) {
+	for _, tt := range []struct {
+		input    func() *Values
+		expected string
+		name     string
+	}{
+		{
+			name: "all",
+			input: func() *Values {
+				values := &Values{}
+				values.MetricsServer.Rest = map[string]interface{}{
+					"foo": foo,
+				}
+				return values
+			},
+			expected: `WARNING! Changes in metrics-server detected, which may require manual migration
+For details please see the following documentations:
+  - https://github.com/SumoLogic/sumologic-kubernetes-collection/blob/main/docs/v3-migration-doc.md
+  - https://github.com/bitnami/charts/tree/5b09f7a7c0d9232f5752840b6c4e5cdc56d7f796/bitnami/metrics-server#to-600`,
+		},
+		{
+			name: "no values",
+			input: func() *Values {
+				values := &Values{}
+				return values
+			},
+			expected: ``,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			val := migrateLog(tt.input())
+			assert.Equal(t, tt.expected, val)
+		})
+	}
+}