examples_test.go

Documentation: github.com/grpc-ecosystem/go-grpc-middleware/logging/zap

     1  package grpc_zap_test
     2  
     3  import (
     4  	"context"
     5  	"time"
     6  
     7  	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
     8  	grpc_zap "github.com/grpc-ecosystem/go-grpc-middleware/logging/zap"
     9  	"github.com/grpc-ecosystem/go-grpc-middleware/logging/zap/ctxzap"
    10  	grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
    11  	pb_testproto "github.com/grpc-ecosystem/go-grpc-middleware/testing/testproto"
    12  	"go.uber.org/zap"
    13  	"go.uber.org/zap/zapcore"
    14  	"google.golang.org/grpc"
    15  )
    16  
    17  var (
    18  	zapLogger  *zap.Logger
    19  	customFunc grpc_zap.CodeToLevel
    20  )
    21  
    22  // Initialization shows a relatively complex initialization sequence.
    23  func Example_initialization() {
    24  	// Shared options for the logger, with a custom gRPC code to log level function.
    25  	opts := []grpc_zap.Option{
    26  		grpc_zap.WithLevels(customFunc),
    27  	}
    28  	// Make sure that log statements internal to gRPC library are logged using the zapLogger as well.
    29  	grpc_zap.ReplaceGrpcLoggerV2(zapLogger)
    30  	// Create a server, make sure we put the grpc_ctxtags context before everything else.
    31  	_ = grpc.NewServer(
    32  		grpc_middleware.WithUnaryServerChain(
    33  			grpc_ctxtags.UnaryServerInterceptor(grpc_ctxtags.WithFieldExtractor(grpc_ctxtags.CodeGenRequestFieldExtractor)),
    34  			grpc_zap.UnaryServerInterceptor(zapLogger, opts...),
    35  		),
    36  		grpc_middleware.WithStreamServerChain(
    37  			grpc_ctxtags.StreamServerInterceptor(grpc_ctxtags.WithFieldExtractor(grpc_ctxtags.CodeGenRequestFieldExtractor)),
    38  			grpc_zap.StreamServerInterceptor(zapLogger, opts...),
    39  		),
    40  	)
    41  }
    42  
    43  // Initialization shows an initialization sequence with the duration field generation overridden.
    44  func Example_initializationWithDurationFieldOverride() {
    45  	opts := []grpc_zap.Option{
    46  		grpc_zap.WithDurationField(func(duration time.Duration) zapcore.Field {
    47  			return zap.Int64("grpc.time_ns", duration.Nanoseconds())
    48  		}),
    49  	}
    50  
    51  	_ = grpc.NewServer(
    52  		grpc_middleware.WithUnaryServerChain(
    53  			grpc_ctxtags.UnaryServerInterceptor(),
    54  			grpc_zap.UnaryServerInterceptor(zapLogger, opts...),
    55  		),
    56  		grpc_middleware.WithStreamServerChain(
    57  			grpc_ctxtags.StreamServerInterceptor(),
    58  			grpc_zap.StreamServerInterceptor(zapLogger, opts...),
    59  		),
    60  	)
    61  }
    62  
    63  // Simple unary handler that adds custom fields to the requests's context. These will be used for all log statements.
    64  func ExampleExtract_unary() {
    65  	_ = func(ctx context.Context, ping *pb_testproto.PingRequest) (*pb_testproto.PingResponse, error) {
    66  		// Add fields the ctxtags of the request which will be added to all extracted loggers.
    67  		grpc_ctxtags.Extract(ctx).Set("custom_tags.string", "something").Set("custom_tags.int", 1337)
    68  
    69  		// Extract a single request-scoped zap.Logger and log messages. (containing the grpc.xxx tags)
    70  		l := ctxzap.Extract(ctx)
    71  		l.Info("some ping")
    72  		l.Info("another ping")
    73  		return &pb_testproto.PingResponse{Value: ping.Value}, nil
    74  	}
    75  }
    76  
    77  func Example_initializationWithDecider() {
    78  	opts := []grpc_zap.Option{
    79  		grpc_zap.WithDecider(func(fullMethodName string, err error) bool {
    80  			// will not log gRPC calls if it was a call to healthcheck and no error was raised
    81  			if err == nil && fullMethodName == "foo.bar.healthcheck" {
    82  				return false
    83  			}
    84  
    85  			// by default everything will be logged
    86  			return true
    87  		}),
    88  	}
    89  
    90  	_ = []grpc.ServerOption{
    91  		grpc_middleware.WithStreamServerChain(
    92  			grpc_ctxtags.StreamServerInterceptor(),
    93  			grpc_zap.StreamServerInterceptor(zap.NewNop(), opts...)),
    94  		grpc_middleware.WithUnaryServerChain(
    95  			grpc_ctxtags.UnaryServerInterceptor(),
    96  			grpc_zap.UnaryServerInterceptor(zap.NewNop(), opts...)),
    97  	}
    98  }
    99
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