snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

authz/audit/stdout/stdout_logger.go

@@ -0,0 +1,110 @@
+/*
+ *
+ * Copyright 2023 gRPC 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 stdout defines an stdout audit logger.
+package stdout
+
+import (
+	"encoding/json"
+	"log"
+	"os"
+	"time"
+
+	"google.golang.org/grpc/authz/audit"
+	"google.golang.org/grpc/grpclog"
+)
+
+var grpcLogger = grpclog.Component("authz-audit")
+
+// Name is the string to identify this logger type in the registry
+const Name = "stdout_logger"
+
+func init() {
+	audit.RegisterLoggerBuilder(&loggerBuilder{
+		goLogger: log.New(os.Stdout, "", 0),
+	})
+}
+
+type event struct {
+	FullMethodName string `json:"rpc_method"`
+	Principal      string `json:"principal"`
+	PolicyName     string `json:"policy_name"`
+	MatchedRule    string `json:"matched_rule"`
+	Authorized     bool   `json:"authorized"`
+	Timestamp      string `json:"timestamp"` // Time when the audit event is logged via Log method
+}
+
+// logger implements the audit.logger interface by logging to standard output.
+type logger struct {
+	goLogger *log.Logger
+}
+
+// Log marshals the audit.Event to json and prints it to standard output.
+func (l *logger) Log(event *audit.Event) {
+	jsonContainer := map[string]any{
+		"grpc_audit_log": convertEvent(event),
+	}
+	jsonBytes, err := json.Marshal(jsonContainer)
+	if err != nil {
+		grpcLogger.Errorf("failed to marshal AuditEvent data to JSON: %v", err)
+		return
+	}
+	l.goLogger.Println(string(jsonBytes))
+}
+
+// loggerConfig represents the configuration for the stdout logger.
+// It is currently empty and implements the audit.Logger interface by embedding it.
+type loggerConfig struct {
+	audit.LoggerConfig
+}
+
+type loggerBuilder struct {
+	goLogger *log.Logger
+}
+
+func (loggerBuilder) Name() string {
+	return Name
+}
+
+// Build returns a new instance of the stdout logger.
+// Passed in configuration is ignored as the stdout logger does not
+// expect any configuration to be provided.
+func (lb *loggerBuilder) Build(audit.LoggerConfig) audit.Logger {
+	return &logger{
+		goLogger: lb.goLogger,
+	}
+}
+
+// ParseLoggerConfig is a no-op since the stdout logger does not accept any configuration.
+func (*loggerBuilder) ParseLoggerConfig(config json.RawMessage) (audit.LoggerConfig, error) {
+	if len(config) != 0 && string(config) != "{}" {
+		grpcLogger.Warningf("Stdout logger doesn't support custom configs. Ignoring:\n%s", string(config))
+	}
+	return &loggerConfig{}, nil
+}
+
+func convertEvent(auditEvent *audit.Event) *event {
+	return &event{
+		FullMethodName: auditEvent.FullMethodName,
+		Principal:      auditEvent.Principal,
+		PolicyName:     auditEvent.PolicyName,
+		MatchedRule:    auditEvent.MatchedRule,
+		Authorized:     auditEvent.Authorized,
+		Timestamp:      time.Now().Format(time.RFC3339Nano),
+	}
+}