Documentation ¶
Overview ¶
`grpc_kit` is a gRPC logging middleware backed by go-kit loggers
It accepts a user-configured `log.Logger` that will be used for logging completed gRPC calls, and be populated into the `context.Context` passed into gRPC handler code.
On calling `StreamServerInterceptor` or `UnaryServerInterceptor` this logging middleware will add gRPC call information to the ctx so that it will be present on subsequent use of the `ctxkit` logger.
If a deadline is present on the gRPC request the grpc.request.deadline tag is populated when the request begins. grpc.request.deadline is a string representing the time (RFC3339) when the current call will expire.
This package also implements request and response *payload* logging, both for server-side and client-side. These will be logged as structured `jsonpb` fields for every message received/sent (both unary and streaming). For that please use `Payload*Interceptor` functions for that. Please note that the user-provided function that determines whetether to log the full request/response payload needs to be written with care, this can significantly slow down gRPC.
*Server Interceptor* Below is a JSON formatted example of a log that would be logged by the server interceptor:
{ "level": "info", // string log level "msg": "finished unary call", // string log message "grpc.code": "OK", // string grpc status code "grpc.method": "Ping", // string method name "grpc.service": "mwitkow.testproto.TestService", // string full name of the called service "grpc.start_time": "2006-01-02T15:04:05Z07:00", // string RFC3339 representation of the start time "grpc.request.deadline": "2006-01-02T15:04:05Z07:00", // string RFC3339 deadline of the current request if supplied "grpc.request.value": "something", // string value on the request "grpc.time_ms": 1.345, // float32 run time of the call in ms "peer.address": { "IP": "127.0.0.1", // string IP address of calling party "Port": 60216, // int port call is coming in on "Zone": "" // string peer zone for caller }, "span.kind": "server", // string client | server "system": "grpc" // string "custom_field": "custom_value", // string user defined field "custom_tags.int": 1337, // int user defined tag on the ctx "custom_tags.string": "something", // string user defined tag on the ctx }
*Payload Interceptor* Below is a JSON formatted example of a log that would be logged by the payload interceptor:
{ "level": "info", // string kit log levels "msg": "client request payload logged as grpc.request.content", // string log message "grpc.request.content": { // object content of RPC request "msg" : { // object kit specific inner object "value": "something", // string defined by caller "sleepTimeMs": 9999 // int defined by caller } }, "grpc.method": "Ping", // string method being called "grpc.service": "mwitkow.testproto.TestService", // string service being called "span.kind": "client", // string client | server "system": "grpc" // string }
Please see examples and tests for examples of use.
Example (Initialization) ¶
Initialization shows a relatively complex initialization sequence.
package main import ( "github.com/go-kit/kit/log" grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware" "github.com/grpc-ecosystem/go-grpc-middleware/logging/kit" grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags" "google.golang.org/grpc" ) var customFunc kit.CodeToLevel func main() { // Logger is used, allowing pre-definition of certain fields by the user. logger := log.NewNopLogger() // Shared options for the logger, with a custom gRPC code to log level function. opts := []kit.Option{ kit.WithLevels(customFunc), } // Create a server, make sure we put the grpc_ctxtags context before everything else. _ = grpc.NewServer( grpc_middleware.WithUnaryServerChain( grpc_ctxtags.UnaryServerInterceptor(grpc_ctxtags.WithFieldExtractor(grpc_ctxtags.CodeGenRequestFieldExtractor)), kit.UnaryServerInterceptor(logger, opts...), ), grpc_middleware.WithStreamServerChain( grpc_ctxtags.StreamServerInterceptor(grpc_ctxtags.WithFieldExtractor(grpc_ctxtags.CodeGenRequestFieldExtractor)), kit.StreamServerInterceptor(logger, opts...), ), ) }
Output:
Example (InitializationWithDurationFieldOverride) ¶
package main import ( "time" "github.com/go-kit/kit/log" grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware" "github.com/grpc-ecosystem/go-grpc-middleware/logging/kit" grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags" "google.golang.org/grpc" ) func main() { // Logger is used, allowing pre-definition of certain fields by the user. logger := log.NewNopLogger() // Shared options for the logger, with a custom duration to log field function. opts := []kit.Option{ kit.WithDurationField(func(duration time.Duration) []interface{} { return kit.DurationToTimeMillisField(duration) }), } _ = grpc.NewServer( grpc_middleware.WithUnaryServerChain( grpc_ctxtags.UnaryServerInterceptor(), kit.UnaryServerInterceptor(logger, opts...), ), grpc_middleware.WithStreamServerChain( grpc_ctxtags.StreamServerInterceptor(), kit.StreamServerInterceptor(logger, opts...), ), ) }
Output:
Index ¶
- Variables
- func DefaultClientCodeToLevel(code codes.Code, logger log.Logger) log.Logger
- func DefaultCodeToLevel(code codes.Code, logger log.Logger) log.Logger
- func DurationToDurationField(duration time.Duration) []interface{}
- func DurationToTimeMillisField(duration time.Duration) []interface{}
- func PayloadStreamClientInterceptor(logger log.Logger, decider grpc_logging.ClientPayloadLoggingDecider) grpc.StreamClientInterceptor
- func PayloadStreamServerInterceptor(logger log.Logger, decider grpc_logging.ServerPayloadLoggingDecider) grpc.StreamServerInterceptor
- func PayloadUnaryClientInterceptor(logger log.Logger, decider grpc_logging.ClientPayloadLoggingDecider) grpc.UnaryClientInterceptor
- func PayloadUnaryServerInterceptor(logger log.Logger, decider grpc_logging.ServerPayloadLoggingDecider) grpc.UnaryServerInterceptor
- func StreamClientInterceptor(logger log.Logger, opts ...Option) grpc.StreamClientInterceptor
- func StreamServerInterceptor(logger log.Logger, opts ...Option) grpc.StreamServerInterceptor
- func UnaryClientInterceptor(logger log.Logger, opts ...Option) grpc.UnaryClientInterceptor
- func UnaryServerInterceptor(logger log.Logger, opts ...Option) grpc.UnaryServerInterceptor
- type CodeToLevel
- type DurationToField
- type Option
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // SystemField is used in every log statement made through grpc_zap. Can be overwritten before any initialization code. SystemField = "grpc" // ServerField is used in every server-side log statement made through grpc_zap.Can be overwritten before initialization. ServerField = "server" )
var DefaultDurationToField = DurationToTimeMillisField
DefaultDurationToField is the default implementation of converting request duration to a kit field.
var ( // JsonPbMarshaller is the marshaller used for serializing protobuf messages. // If needed, this variable can be reassigned with a different marshaller with the same Marshal() signature. JsonPbMarshaller grpc_logging.JsonPbMarshaler = &jsonpb.Marshaler{} )
Functions ¶
func DefaultClientCodeToLevel ¶
DefaultClientCodeToLevel is the default implementation of gRPC return codes to log levels for client side.
func DefaultCodeToLevel ¶
DefaultCodeToLevel is the default implementation of gRPC return codes and interceptor log level for server side.
func DurationToDurationField ¶
DurationToDurationField uses a Duration field to log the request duration and leaves it up to Log's encoder settings to determine how that is output.
func DurationToTimeMillisField ¶
DurationToTimeMillisField converts the duration to milliseconds and uses the key `grpc.time_ms`.
func PayloadStreamClientInterceptor ¶
func PayloadStreamClientInterceptor(logger log.Logger, decider grpc_logging.ClientPayloadLoggingDecider) grpc.StreamClientInterceptor
PayloadStreamClientInterceptor returns a new streaming client interceptor that logs the paylods of requests and responses.
func PayloadStreamServerInterceptor ¶
func PayloadStreamServerInterceptor(logger log.Logger, decider grpc_logging.ServerPayloadLoggingDecider) grpc.StreamServerInterceptor
PayloadStreamServerInterceptor returns a new server server interceptors that logs the payloads of requests.
This *only* works when placed *after* the `kit.StreamServerInterceptor`. However, the logging can be done to a separate instance of the logger.
func PayloadUnaryClientInterceptor ¶
func PayloadUnaryClientInterceptor(logger log.Logger, decider grpc_logging.ClientPayloadLoggingDecider) grpc.UnaryClientInterceptor
PayloadUnaryClientInterceptor returns a new unary client interceptor that logs the paylods of requests and responses.
func PayloadUnaryServerInterceptor ¶
func PayloadUnaryServerInterceptor(logger log.Logger, decider grpc_logging.ServerPayloadLoggingDecider) grpc.UnaryServerInterceptor
PayloadUnaryServerInterceptor returns a new unary server interceptors that logs the payloads of requests.
This *only* works when placed *after* the `kit.UnaryServerInterceptor`. However, the logging can be done to a separate instance of the logger.
func StreamClientInterceptor ¶
func StreamClientInterceptor(logger log.Logger, opts ...Option) grpc.StreamClientInterceptor
StreamClientInterceptor returns a new streaming client interceptor that optionally logs the execution of external gRPC calls.
func StreamServerInterceptor ¶
func StreamServerInterceptor(logger log.Logger, opts ...Option) grpc.StreamServerInterceptor
StreamServerInterceptor returns a new stream server interceptors that adds kit.Logger to the context.
func UnaryClientInterceptor ¶
func UnaryClientInterceptor(logger log.Logger, opts ...Option) grpc.UnaryClientInterceptor
UnaryClientInterceptor returns a new unary client interceptor that optionally logs the execution of external gRPC calls.
func UnaryServerInterceptor ¶
func UnaryServerInterceptor(logger log.Logger, opts ...Option) grpc.UnaryServerInterceptor
UnaryServerInterceptor returns a new unary server interceptors that adds kit.Logger to the context.
Types ¶
type CodeToLevel ¶
CodeToLevel function defines the mapping between gRPC return codes and interceptor log level.
type DurationToField ¶
DurationToField function defines how to produce duration fields for logging
type Option ¶
type Option func(*options)
func WithCodes ¶
func WithCodes(f grpc_logging.ErrorToCode) Option
WithCodes customizes the function for mapping errors to error codes.
func WithDecider ¶
func WithDecider(f grpc_logging.Decider) Option
WithDecider customizes the function for deciding if the gRPC interceptor logs should log.
Example ¶
package main import ( "github.com/go-kit/kit/log" grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware" "github.com/grpc-ecosystem/go-grpc-middleware/logging/kit" grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags" "google.golang.org/grpc" ) func main() { opts := []kit.Option{ kit.WithDecider(func(methodFullName string, err error) bool { // will not log gRPC calls if it was a call to healthcheck and no error was raised if err == nil && methodFullName == "blah.foo.healthcheck" { return false } // by default you will log all calls return true }), } _ = []grpc.ServerOption{ grpc_middleware.WithStreamServerChain( grpc_ctxtags.StreamServerInterceptor(), kit.StreamServerInterceptor(log.NewNopLogger(), opts...)), grpc_middleware.WithUnaryServerChain( grpc_ctxtags.UnaryServerInterceptor(), kit.UnaryServerInterceptor(log.NewNopLogger(), opts...)), } }
Output:
func WithDurationField ¶
func WithDurationField(f DurationToField) Option
WithDurationField customizes the function for mapping request durations to log fields.
func WithLevels ¶
func WithLevels(f CodeToLevel) Option
WithLevels customizes the function for mapping gRPC return codes and interceptor log level statements.