gcp/observability: implement logging via binarylog

gcp/observability/config.go

@@ -0,0 +1,102 @@
+/*
+ *
+ * Copyright 2022 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 observability
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"regexp"
+
+	gcplogging "cloud.google.com/go/logging"
+	"golang.org/x/oauth2/google"
+	configpb "google.golang.org/grpc/observability/internal/config"
+	"google.golang.org/protobuf/encoding/protojson"
+)
+
+const (
+	envObservabilityConfig    = "GRPC_CONFIG_OBSERVABILITY"
+	envProjectID              = "GOOGLE_CLOUD_PROJECT"
+	logFilterPatternRegexpStr = `^([\w./]+)/((?:\w+)|[*])$`
+)
+
+var logFilterPatternRegexp = regexp.MustCompile(logFilterPatternRegexpStr)
+
+// fetchDefaultProjectID fetches the default GCP project id from environment.
+func fetchDefaultProjectID(ctx context.Context) string {
+	// Step 1: Check ENV var
+	if s := os.Getenv(envProjectID); s != "" {
+		logger.Infof("Found project ID from env %v: %v", envProjectID, s)
+		return s
+	}
+	// Step 2: Check default credential
+	credentials, err := google.FindDefaultCredentials(ctx, gcplogging.WriteScope)
+	if err != nil {
+		logger.Infof("Failed to locate Google Default Credential: %v", err)
+		return ""
+	}
+	if credentials.ProjectID == "" {
+		logger.Infof("Failed to find project ID in default credential: %v", err)
+		return ""
+	}
+	logger.Infof("Found project ID from Google Default Credential: %v", credentials.ProjectID)
+	return credentials.ProjectID
+}
+
+func validateFilters(config *configpb.ObservabilityConfig) error {
+	for _, filter := range config.GetLogFilters() {
+		if filter.Pattern == "*" {
+			continue
+		}
+		match := logFilterPatternRegexp.FindStringSubmatch(filter.Pattern)
+		if match == nil {
+			return fmt.Errorf("invalid log filter pattern: %v", filter.Pattern)
+		}
+	}
+	return nil
+}
+
+func parseObservabilityConfig() (*configpb.ObservabilityConfig, error) {
+	// Parse the config from ENV var
+	if content := os.Getenv(envObservabilityConfig); content != "" {
+		var config configpb.ObservabilityConfig
+		if err := protojson.Unmarshal([]byte(content), &config); err != nil {
+			return nil, fmt.Errorf("error parsing observability config from env %v: %v", envObservabilityConfig, err)
+		}
+		if err := validateFilters(&config); err != nil {
+			return nil, fmt.Errorf("error parsing observability config: %v", err)
+		}
+		logger.Infof("Parsed ObservabilityConfig: %+v", &config)
+		return &config, nil
+	}
+	// If the ENV var doesn't exist, do nothing
+	return nil, nil
+}
+
+func ensureProjectIDInObservabilityConfig(ctx context.Context, config *configpb.ObservabilityConfig) error {
+	if config.GetDestinationProjectId() == "" {
+		// Try to fetch the GCP project id
+		projectID := fetchDefaultProjectID(ctx)
+		if projectID == "" {
+			return fmt.Errorf("empty destination project ID")
+		}
+		config.DestinationProjectId = projectID
+	}
+	return nil
+}

gcp/observability/exporting.go

@@ -0,0 +1,128 @@
+/*
+ *
+ * Copyright 2022 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 observability
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	gcplogging "cloud.google.com/go/logging"
+	grpclogrecordpb "google.golang.org/grpc/observability/internal/logging"
+	"google.golang.org/protobuf/encoding/protojson"
+)
+
+// loggingExporter is the interface of logging exporter for gRPC Observability.
+// In future, we might expose this to allow users provide custom exporters. But
+// now, it exists for testing purposes.
+type loggingExporter interface {
+	// EmitGrpcLogRecord writes a gRPC LogRecord to cache without blocking.
+	EmitGrpcLogRecord(*grpclogrecordpb.GrpcLogRecord)
+	// Close flushes all pending data and closes the exporter.
+	Close() error
+}
+
+type cloudLoggingExporter struct {
+	projectID string
+	client    *gcplogging.Client
+	logger    *gcplogging.Logger
+}
+
+func newCloudLoggingExporter(ctx context.Context, projectID string) (*cloudLoggingExporter, error) {
+	c, err := gcplogging.NewClient(ctx, fmt.Sprintf("projects/%v", projectID))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create cloudLoggingExporter: %v", err)
+	}
+	defer logger.Infof("Successfully created cloudLoggingExporter")
+	customTags := getCustomTags(os.Environ())
+	if len(customTags) != 0 {
+		logger.Infof("Adding custom tags: %+v", customTags)
+	}
+	return &cloudLoggingExporter{
+		projectID: projectID,
+		client:    c,
+		logger:    c.Logger("grpc", gcplogging.CommonLabels(customTags)),
+	}, nil
+}
+
+// mapLogLevelToSeverity maps the gRPC defined log level to Cloud Logging's
+// Severity. The canonical definition can be found at
+// https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry#LogSeverity.
+var logLevelToSeverity = map[grpclogrecordpb.GrpcLogRecord_LogLevel]gcplogging.Severity{
+	grpclogrecordpb.GrpcLogRecord_LOG_LEVEL_UNKNOWN:  0,
+	grpclogrecordpb.GrpcLogRecord_LOG_LEVEL_TRACE:    100, // Cloud Logging doesn't have a trace level, treated as DEBUG.
+	grpclogrecordpb.GrpcLogRecord_LOG_LEVEL_DEBUG:    100,
+	grpclogrecordpb.GrpcLogRecord_LOG_LEVEL_INFO:     200,
+	grpclogrecordpb.GrpcLogRecord_LOG_LEVEL_WARN:     400,
+	grpclogrecordpb.GrpcLogRecord_LOG_LEVEL_ERROR:    500,
+	grpclogrecordpb.GrpcLogRecord_LOG_LEVEL_CRITICAL: 600,
+}
+
+var protoToJSONOptions = &protojson.MarshalOptions{
+	UseProtoNames:  true,
+	UseEnumNumbers: false,
+}
+
+func (cle *cloudLoggingExporter) EmitGrpcLogRecord(l *grpclogrecordpb.GrpcLogRecord) {
+	// Converts the log record content to a more readable format via protojson.
+	jsonBytes, err := protoToJSONOptions.Marshal(l)
+	if err != nil {
+		logger.Infof("Unable to marshal log record: %v", l)
+		return
+	}
+	var payload map[string]interface{}
+	err = json.Unmarshal(jsonBytes, &payload)
+	if err != nil {
+		logger.Infof("Unable to unmarshal bytes to JSON: %v", jsonBytes)
+		return
+	}
+	entry := gcplogging.Entry{
+		Timestamp: l.Timestamp.AsTime(),
+		Severity:  logLevelToSeverity[l.LogLevel],
+		Payload:   payload,
+	}
+	cle.logger.Log(entry)
+	if logger.V(2) {
+		logger.Infof("Uploading event to CloudLogging: %+v", entry)
+	}
+}
+
+func (cle *cloudLoggingExporter) Close() error {
+	var errFlush, errClose error
+	if cle.logger != nil {
+		errFlush = cle.logger.Flush()
+	}
+	if cle.client != nil {
+		errClose = cle.client.Close()
+	}
+	if errFlush != nil && errClose != nil {
+		return fmt.Errorf("failed to close exporter. Flush failed: %v; Close failed: %v", errFlush, errClose)
+	}
+	if errFlush != nil {
+		return errFlush
+	}
+	if errClose != nil {
+		return errClose
+	}
+	cle.logger = nil
+	cle.client = nil
+	logger.Infof("Closed CloudLogging exporter")
+	return nil
+}

gcp/observability/go.mod

@@ -0,0 +1,14 @@
+module google.golang.org/grpc/observability
+
+go 1.14
+
+require (
+	cloud.google.com/go/logging v1.4.2
+	github.com/golang/protobuf v1.5.2
+	github.com/google/uuid v1.3.0
+	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8
+	google.golang.org/grpc v1.43.0
+	google.golang.org/protobuf v1.27.1
+)
+
+replace google.golang.org/grpc => ../../