logger

README

grpc-elasticsearch-logger

Logger for gRPC server to elasticsearch with elastic APM trace ID

Documentation

Overview

Package logger is used to log all intercepted unary and stream calls. The package exports the `NewLogger` function which sets up a logger with the elogrus hook and returns it.

The logger can be configured using environment variables:

LOG_LEVEL (default: "error") - Defines the log level of the logger, possible values:

"panic", "fatal", "error", "warn", "warning", "info", "debug", "trace"

LOG_INDEX (default: "log") - Defines the index to which the logs would be indexed to, the logs would be indexed to index pattern LOG_INDEX-*, where * is the current day's date in the format 'YYYY.MM.DD'

ELASTICSEARCH_URL (default: http://localhost:9200) - Defines the url of the elasticsearch server to index the logs to.

HOST_NAME (default: executable name) - Defines the host name of the server that is using the logger, which will be logged under 'Host' field.

There's the `ElasticsearchLoggerServerInterceptor` function which sets up a `grpc.ServerOption` to intercept streams and unary calls with `*logrus.Entry` of the logger, created with `NewLogger`, and the options given to it. Returns the `grpc.ServerOption` which will be used in `grpc.NewServer` to log all incoming stream and unary calls. It also sets up the APM agent's unary server interceptor to log metrics to elastic APM.

The function `ExtractTraceParent` gets a `context.Context` which holds the "Elastic-Apm-Traceparent", which is the HTTP header for trace propagation, and returns the trace id.

Index

• func DefaultDecider(string) bool
• func ElasticsearchLoggerServerInterceptor(logrusEntry *logrus.Entry, serverPayloadLoggingDecider DeciderFunc, ...) []grpc.ServerOption
• func ExtractTraceParent(ctx context.Context) string
• func NewLogger() *logrus.Logger
• func RequestExtractor(entry *logrus.Entry, decider DeciderFunc) grpc_ctxtags.RequestFieldExtractorFunc
• type DeciderFunc
  • func IgnoreServerMethodsDecider(fullIgnoredMethodNames ...string) DeciderFunc
• type JSONPbMarshaller
  • func (j *JSONPbMarshaller) MarshalJSON() ([]byte, error)

Functions

func DefaultDecider

func DefaultDecider(string) bool

DefaultDecider logs every payload.

func ElasticsearchLoggerServerInterceptor

func ElasticsearchLoggerServerInterceptor(
	logrusEntry *logrus.Entry,
	serverPayloadLoggingDecider DeciderFunc,
	extractInitialRequestDecider DeciderFunc,
	opts ...grpc_logrus.Option,
) []grpc.ServerOption

ElasticsearchLoggerServerInterceptor sets up a `grpc.ServerOption` to intercept streams with `*logrus.Entry` of the logger, created with `NewLogger`, and the options given to it. Returns the `grpc.ServerOption` which will be used in `grpc.NewServer` to log all incoming calls.

func ExtractTraceParent

func ExtractTraceParent(ctx context.Context) string

ExtractTraceParent gets a `context.Context` which holds the "Elastic-Apm-Traceparent", which is the HTTP header for trace propagation, and returns the trace id.

func NewLogger

func NewLogger() *logrus.Logger

NewLogger creates a `*logrus.Logger` with `elogrus` hook, which logs to elasticsearch, and returns it.

func RequestExtractor

func RequestExtractor(entry *logrus.Entry, decider DeciderFunc) grpc_ctxtags.RequestFieldExtractorFunc

RequestExtractor extracts the request and logs it as json under the key "grpc.request.content". Pass decider function to not extract the requests for certain methods.

Types

type DeciderFunc

type DeciderFunc func(fullMethodName string) bool

DeciderFunc is a function type to decide whether to create a log for fullMethodName.

func IgnoreServerMethodsDecider

func IgnoreServerMethodsDecider(fullIgnoredMethodNames ...string) DeciderFunc

IgnoreServerMethodsDecider ignores logging the payload of method that is equal to any string of fullIgnoredMethodNames.

type JSONPbMarshaller

type JSONPbMarshaller struct {
	proto.Message
}

JSONPbMarshaller is a struct used to marshal a protobuf message to JSON.

func (*JSONPbMarshaller) MarshalJSON

func (j *JSONPbMarshaller) MarshalJSON() ([]byte, error)

MarshalJSON marshals a protobuf message to JSON.