✨ util: Warning handler that discards a default set of messages

Author: dlipovetsky

util/apiwarnings/default.go

@@ -0,0 +1,49 @@
+/*
+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 apiwarnings
+
+import (
+	"fmt"
+	"regexp"
+
+	"github.com/go-logr/logr"
+
+	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
+)
+
+// DomainQualifiedFinalizerWarning is a regular expression that matches a
+// warning that the API server returns when a finalizer is not domain-qualified.
+func DomainQualifiedFinalizerWarning(domain string) *regexp.Regexp {
+	return regexp.MustCompile(
+		fmt.Sprintf("^metadata.finalizers:.*%s.*prefer a domain-qualified finalizer name to avoid accidental conflicts with other finalizer writers$", domain),
+	)
+}
+
+// DefaultHandler is a handler that discards warnings that are the result of
+// decisions made by the Cluster API project, but cannot be immediately
+// addressed, and are therefore not helpful to the user.
+func DefaultHandler(l logr.Logger) *DiscardMatchingHandler {
+	return NewDiscardMatchingHandler(
+		l,
+		DiscardMatchingHandlerOptions{
+			Deduplicate: true,
+			Expressions: []regexp.Regexp{
+				*DomainQualifiedFinalizerWarning(clusterv1.GroupVersion.Group),
+			},
+		},
+	)
+}

util/apiwarnings/default_test.go

@@ -0,0 +1,61 @@
+/*
+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 apiwarnings
+
+import (
+	"testing"
+
+	"github.com/go-logr/logr/funcr"
+	. "github.com/onsi/gomega"
+)
+
+func TestDefaultHandler(t *testing.T) {
+	tests := []struct {
+		name       string
+		code       int
+		message    string
+		wantLogged bool
+	}{
+		{
+			name:       "log, if warning does not match any expression",
+			code:       299,
+			message:    `metadata.finalizers: "foo.example.com": prefer a domain-qualified finalizer name to avoid accidental conflicts with other finalizer writers`,
+			wantLogged: true,
+		},
+		{
+			name:       "do not log, if warning matches at least one expression",
+			code:       299,
+			message:    `metadata.finalizers: "dockermachine.infrastructure.cluster.x-k8s.io": prefer a domain-qualified finalizer name to avoid accidental conflicts with other finalizer writers`,
+			wantLogged: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			g := NewWithT(t)
+			logged := false
+			h := DefaultHandler(
+				funcr.New(func(_, _ string) {
+					logged = true
+				},
+					funcr.Options{},
+				),
+			)
+			h.HandleWarningHeader(tt.code, "", tt.message)
+			g.Expect(logged).To(Equal(tt.wantLogged))
+		})
+	}
+}