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 LogError(logger *logrus.Logger, err error)
• func NewLogger() *logrus.Logger
• func RequestExtractor(entry *logrus.Entry, decider DeciderFunc) grpc_ctxtags.RequestFieldExtractorFunc
• func SetLogger(config *Config) gin.HandlerFunc
• func StartSpan(ctx context.Context, name string) (*apm.Span, context.Context)
• type Config
• 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 LogError

func LogError(logger *logrus.Logger, err error)

LogError logs err with logger.Errorf if err is non-nil.

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.

func SetLogger

func SetLogger(config *Config) gin.HandlerFunc

SetLogger initializes the logging middleware.

func StartSpan

func StartSpan(ctx context.Context, name string) (*apm.Span, context.Context)

StartSpan starts an externalGRPCSpanType span under the transaction in ctx, returns the created span and the context with the traceparent header matadata.

Types

type Config

type Config struct {
	Logger             *logrus.Logger
	SkipBodyPath       []string
	SkipBodyPathRegexp *regexp.Regexp
	SkipPath           []string
	SkipPathRegexp     *regexp.Regexp
}

Config is the configuration struct for the logger, Logger - a logrus Logger to use in the logger. SkipPath - path to skip logging. SkipPathRegexp - a regex to skip paths.

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.