[3.5] chore(e2e): backport TestNoErrorLogsDuringNormalOperations test

tests/e2e/logging_test.go

@@ -0,0 +1,91 @@
+// Copyright 2024 The etcd 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 e2e
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"go.etcd.io/etcd/tests/v3/framework/e2e"
+)
+
+func TestNoErrorLogsDuringNormalOperations(t *testing.T) {
+	tests := []struct {
+		name          string
+		clusterSize   int
+		allowedErrors map[string]bool
+	}{
+		{
+			name:          "single node cluster",
+			clusterSize:   1,
+			allowedErrors: map[string]bool{},
+		},
+		{
+			name:          "three node cluster",
+			clusterSize:   3,
+			allowedErrors: map[string]bool{},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			e2e.BeforeTest(t)
+
+			epc, err := e2e.NewEtcdProcessCluster(t,
+				&e2e.EtcdProcessClusterConfig{
+					LogLevel:    "debug",
+					ClusterSize: tc.clusterSize,
+				},
+			)
+			require.NoError(t, err)
+			defer epc.Close()
+
+			require.Lenf(t, epc.Procs, tc.clusterSize, "embedded etcd cluster process count is not as expected")
+
+			// Collect the handle of logs before closing the processes.
+			var logHandles []e2e.LogsExpect
+			for i := range tc.clusterSize {
+				logHandles = append(logHandles, epc.Procs[i].Logs())
+			}
+
+			time.Sleep(time.Second)
+			err = epc.Close()
+			require.NoErrorf(t, err, "closing etcd processes")
+
+			// Now that the processes are closed we can collect all log lines. This must happen after closing, else we
+			// might not get all log lines.
+			var lines []string
+			for _, h := range logHandles {
+				lines = append(lines, h.Lines()...)
+			}
+			require.NotEmptyf(t, lines, "expected at least one log line")
+
+			var entry logEntry
+			for _, line := range lines {
+				err := json.Unmarshal([]byte(line), &entry)
+				require.NoErrorf(t, err, "parse log line as json, line: %s", line)
+
+				if tc.allowedErrors[entry.Message] {
+					continue
+				}
+
+				require.NotEqualf(t, "error", entry.Level, "error level log message found: %s", line)
+			}
+		})
+	}
+}