O11Y: Added support for custom tags (#5565)

* O11Y: Added support for custom tags

gcp/observability/config.go

@@ -28,8 +28,6 @@ import (
 
 	gcplogging "cloud.google.com/go/logging"
 	"golang.org/x/oauth2/google"
-	configpb "google.golang.org/grpc/gcp/observability/internal/config"
-	"google.golang.org/protobuf/encoding/protojson"
 )
 
 const (
@@ -41,6 +39,69 @@ const (
 
 var logFilterPatternRegexp = regexp.MustCompile(logFilterPatternRegexpStr)
 
+// logFilter represents a method logging configuration.
+type logFilter struct {
+	// Pattern is a string which can select a group of method names. By
+	// default, the Pattern is an empty string, matching no methods.
+	//
+	// Only "*" Wildcard is accepted for Pattern. A Pattern is in the form
+	// of <service>/<method> or just a character "*" .
+	//
+	// If the Pattern is "*", it specifies the defaults for all the
+	// services; If the Pattern is <service>/*, it specifies the defaults
+	// for all methods in the specified service <service>; If the Pattern is
+	// */<method>, this is not supported.
+	//
+	// Examples:
+	//  - "Foo/Bar" selects only the method "Bar" from service "Foo"
+	//  - "Foo/*" selects all methods from service "Foo"
+	//  - "*" selects all methods from all services.
+	Pattern string `json:"pattern,omitempty"`
+	// HeaderBytes is the number of bytes of each header to log. If the size of
+	// the header is greater than the defined limit, content past the limit will
+	// be truncated. The default value is 0.
+	HeaderBytes int32 `json:"header_bytes,omitempty"`
+	// MessageBytes is the number of bytes of each message to log. If the size
+	// of the message is greater than the defined limit, content pass the limit
+	// will be truncated. The default value is 0.
+	MessageBytes int32 `json:"message_bytes,omitempty"`
+}
+
+// config is configuration for observability behaviors. By default, no
+// configuration is required for tracing/metrics/logging to function. This
+// config captures the most common knobs for gRPC users. It's always possible to
+// override with explicit config in code.
+type config struct {
+	// EnableCloudTrace represents whether the tracing data upload to
+	// CloudTrace should be enabled or not.
+	EnableCloudTrace bool `json:"enable_cloud_trace,omitempty"`
+	// EnableCloudMonitoring represents whether the metrics data upload to
+	// CloudMonitoring should be enabled or not.
+	EnableCloudMonitoring bool `json:"enable_cloud_monitoring,omitempty"`
+	// EnableCloudLogging represents Whether the logging data upload to
+	// CloudLogging should be enabled or not.
+	EnableCloudLogging bool `json:"enable_cloud_logging,omitempty"`
+	// DestinationProjectID is the destination GCP project identifier for the
+	// uploading log entries. If empty, the gRPC Observability plugin will
+	// attempt to fetch the project_id from the GCP environment variables, or
+	// from the default credentials.
+	DestinationProjectID string `json:"destination_project_id,omitempty"`
+	// LogFilters is a list of method config. The order matters here - the first
+	// Pattern which matches the current method will apply the associated config
+	// options in the logFilter. Any other logFilter that also matches that
+	// comes later will be ignored. So a logFilter of "*/*" should appear last
+	// in this list.
+	LogFilters []logFilter `json:"log_filters,omitempty"`
+	// GlobalTraceSamplingRate is the global setting that controls the
+	// probability of a RPC being traced. For example, 0.05 means there is a 5%
+	// chance for a RPC to be traced, 1.0 means trace every call, 0 means don’t
+	// start new traces.
+	GlobalTraceSamplingRate float64 `json:"global_trace_sampling_rate,omitempty"`
+	// CustomTags a list of custom tags that will be attached to every log
+	// entry.
+	CustomTags map[string]string `json:"custom_tags,omitempty"`
+}
+
 // fetchDefaultProjectID fetches the default GCP project id from environment.
 func fetchDefaultProjectID(ctx context.Context) string {
 	// Step 1: Check ENV var
@@ -62,25 +123,25 @@ func fetchDefaultProjectID(ctx context.Context) string {
 	return credentials.ProjectID
 }
 
-func validateFilters(config *configpb.ObservabilityConfig) error {
-	for _, filter := range config.GetLogFilters() {
+func validateFilters(config *config) error {
+	for _, filter := range config.LogFilters {
 		if filter.Pattern == "*" {
 			continue
 		}
 		match := logFilterPatternRegexp.FindStringSubmatch(filter.Pattern)
 		if match == nil {
-			return fmt.Errorf("invalid log filter pattern: %v", filter.Pattern)
+			return fmt.Errorf("invalid log filter Pattern: %v", filter.Pattern)
 		}
 	}
 	return nil
 }
 
 // unmarshalAndVerifyConfig unmarshals a json string representing an
-// observability config into its protobuf format, and also verifies the
+// observability config into its internal go format, and also verifies the
 // configuration's fields for validity.
-func unmarshalAndVerifyConfig(rawJSON json.RawMessage) (*configpb.ObservabilityConfig, error) {
-	var config configpb.ObservabilityConfig
-	if err := protojson.Unmarshal(rawJSON, &config); err != nil {
+func unmarshalAndVerifyConfig(rawJSON json.RawMessage) (*config, error) {
+	var config config
+	if err := json.Unmarshal(rawJSON, &config); err != nil {
 		return nil, fmt.Errorf("error parsing observability config: %v", err)
 	}
 	if err := validateFilters(&config); err != nil {
@@ -93,7 +154,7 @@ func unmarshalAndVerifyConfig(rawJSON json.RawMessage) (*configpb.ObservabilityC
 	return &config, nil
 }
 
-func parseObservabilityConfig() (*configpb.ObservabilityConfig, error) {
+func parseObservabilityConfig() (*config, error) {
 	if fileSystemPath := os.Getenv(envObservabilityConfigJSON); fileSystemPath != "" {
 		content, err := ioutil.ReadFile(fileSystemPath) // TODO: Switch to os.ReadFile once dropped support for go 1.15
 		if err != nil {
@@ -107,14 +168,14 @@ func parseObservabilityConfig() (*configpb.ObservabilityConfig, error) {
 	return nil, nil
 }
 
-func ensureProjectIDInObservabilityConfig(ctx context.Context, config *configpb.ObservabilityConfig) error {
-	if config.GetDestinationProjectId() == "" {
+func ensureProjectIDInObservabilityConfig(ctx context.Context, config *config) error {
+	if config.DestinationProjectID == "" {
 		// Try to fetch the GCP project id
 		projectID := fetchDefaultProjectID(ctx)
 		if projectID == "" {
 			return fmt.Errorf("empty destination project ID")
 		}
-		config.DestinationProjectId = projectID
+		config.DestinationProjectID = projectID
 	}
 	return nil
 }

gcp/observability/exporting.go

@@ -22,7 +22,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"os"
 
 	gcplogging "cloud.google.com/go/logging"
 	grpclogrecordpb "google.golang.org/grpc/gcp/observability/internal/logging"
@@ -45,20 +44,19 @@ type cloudLoggingExporter struct {
 	logger    *gcplogging.Logger
 }
 
-func newCloudLoggingExporter(ctx context.Context, projectID string) (*cloudLoggingExporter, error) {
-	c, err := gcplogging.NewClient(ctx, fmt.Sprintf("projects/%v", projectID))
+func newCloudLoggingExporter(ctx context.Context, config *config) (*cloudLoggingExporter, error) {
+	c, err := gcplogging.NewClient(ctx, fmt.Sprintf("projects/%v", config.DestinationProjectID))
 	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)
+	if len(config.CustomTags) != 0 {
+		logger.Infof("Adding custom tags: %+v", config.CustomTags)
 	}
 	return &cloudLoggingExporter{
-		projectID: projectID,
+		projectID: config.DestinationProjectID,
 		client:    c,
-		logger:    c.Logger("microservices.googleapis.com/observability/grpc", gcplogging.CommonLabels(customTags)),
+		logger:    c.Logger("microservices.googleapis.com/observability/grpc", gcplogging.CommonLabels(config.CustomTags)),
 	}, nil
 }