authz: Stdout logger

authz/audit/stdout/stdout_logger.go

@@ -0,0 +1,99 @@
+/*
+ *
+ * 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"
+	"time"
+
+	"google.golang.org/grpc/authz/audit"
+	"google.golang.org/grpc/grpclog"
+)
+
+var grpcLogger = grpclog.Component("authz-audit")
+
+func init() {
+	audit.RegisterLoggerBuilder(&loggerBuilder{})
+}
+
+type event struct {
+	FullMethodName string `json:"fullMethodName"`
+	Principal      string `json:"principal"`
+	PolicyName     string `json:"policyName"`
+	MatchedRule    string `json:"matchedRule"`
+	Authorized     bool   `json:"authorized"`
+	// Timestamp represents time when Log method prints the audit.Event
+	Timestamp string `json:"timestamp"`
+}
+
+// StdoutLogger contains Log method to be invoked to log audit.Event.
+type logger struct {
+}
+
+// Log marshals the audit.Event to json and prints it using log.go
+func (logger *logger) Log(event *audit.Event) {
+	jsonBytes, err := json.Marshal(convertEvent(event))
+	if err != nil {
+		grpcLogger.Errorf("failed to marshal AuditEvent data to JSON: %v", err)
+	}
+	log.Println(string(jsonBytes))
+}
+
+const (
+	stdName = "stdout"
+)
+
+// LoggerConfig embeds audit.LoggerConfig
+type LoggerConfig struct {
+	audit.LoggerConfig
+}
+
+// StdoutLoggerBuilder contains information to build StdoutLogger
+type loggerBuilder struct{}
+
+// Name returns a hardcoded name of the StdoutLogger
+func (loggerBuilder) Name() string {
+	return stdName
+}
+
+// Build returns default StdoutLogger (audit.LoggerConfig is ignored)
+func (*loggerBuilder) Build(audit.LoggerConfig) audit.Logger {
+	return &logger{}
+}
+
+// ParseLoggerConfig returns LoggerConfig (json.RawMessage is ignored)
+func (*loggerBuilder) ParseLoggerConfig(config json.RawMessage) (audit.LoggerConfig, error) {
+	if config != nil {
+		grpcLogger.Warningf("Config value %v ignored, StdoutLogger doesn't support custom configs", 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.RFC3339),
+	}
+}

authz/audit/stdout/stdout_logger_test.go

@@ -0,0 +1,117 @@
+/*
+ *
+ * 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
+
+import (
+	"bytes"
+	"encoding/json"
+	"log"
+	"strings"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"google.golang.org/grpc/authz/audit"
+	"google.golang.org/grpc/internal/grpctest"
+)
+
+var (
+	content     = json.RawMessage(`{"name": "conf", "val": "to be ignored"}`)
+	builder     = &loggerBuilder{}
+	config, _   = builder.ParseLoggerConfig(content)
+	auditLogger = builder.Build(config)
+)
+
+type s struct {
+	grpctest.Tester
+}
+
+func Test(t *testing.T) {
+	grpctest.RunSubTests(t, s{})
+}
+
+func (s) TestStdoutLogger_Log(t *testing.T) {
+	tests := map[string]struct {
+		event       *audit.Event
+		wantMessage string
+		wantErr     string
+	}{
+		"few fields": {
+			event:       &audit.Event{PolicyName: "test policy", Principal: "test principal"},
+			wantMessage: `{"fullMethodName":"","principal":"test principal","policyName":"test policy","matchedRule":"","authorized":false`,
+		},
+		"all fields": {
+			event: &audit.Event{
+				FullMethodName: "/helloworld.Greeter/SayHello",
+				Principal:      "spiffe://example.org/ns/default/sa/default/backend",
+				PolicyName:     "example-policy",
+				MatchedRule:    "dev-access",
+				Authorized:     true,
+			},
+			wantMessage: `{"fullMethodName":"/helloworld.Greeter/SayHello",` +
+				`"principal":"spiffe://example.org/ns/default/sa/default/backend","policyName":"example-policy",` +
+				`"matchedRule":"dev-access","authorized":true`,
+		},
+	}
+
+	var buf bytes.Buffer
+	log.SetOutput(&buf)
+	log.SetFlags(0)
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			auditLogger.Log(test.event)
+			var e event
+			err := json.Unmarshal(buf.Bytes(), &e)
+			if err != nil {
+				t.Fatalf("Unexpected error\n%v", err)
+			}
+			if len(strings.TrimSpace(e.Timestamp)) == 0 {
+				t.Fatalf("Resulted event has no timestamp\n%v", e)
+			}
+
+			if diff := cmp.Diff(trimEvent(e), test.event); diff != "" {
+				t.Fatalf("Unexpected message\ndiff (-want +got):\n%s", diff)
+			}
+			buf.Reset()
+		})
+	}
+
+}
+
+func (s) TestStdoutLoggerBuilder_NilConfig(t *testing.T) {
+	builder = &loggerBuilder{}
+	config, err := builder.ParseLoggerConfig(nil)
+	if err != nil {
+		t.Fatalf("Unexpected error\n%v", err)
+	}
+	auditLogger = builder.Build(config)
+	if auditLogger == nil {
+		t.Fatalf("Unexpected error\nAuditLogger is nil")
+	}
+}
+
+func trimEvent(testEvent event) *audit.Event {
+	return &audit.Event{
+		FullMethodName: testEvent.FullMethodName,
+		Principal:      testEvent.Principal,
+		PolicyName:     testEvent.PolicyName,
+		MatchedRule:    testEvent.MatchedRule,
+		Authorized:     testEvent.Authorized,
+	}
+}