logrus-stackdriver-formatter

logrus formatter for Stackdriver.

In addition to supporting level-based logging to Stackdriver, for Error, Fatal and Panic levels it will append error context for Error Reporting.

Installation

go get -u github.com/TV4/logrus-stackdriver-formatter

Usage

package main

import (
    "github.com/sirupsen/logrus"
    stackdriver "github.com/TV4/logrus-stackdriver-formatter"
)

var log = logrus.New()

func init() {
    log.Formatter = stackdriver.NewFormatter(
        stackdriver.WithService("your-service"),
        stackdriver.WithVersion("v0.1.0"),
    )
    log.Level = logrus.DebugLevel

    log.Info("ready to log!")
}

Here's a sample entry (prettified) from the example:

{
  "serviceContext": {
    "service": "test-service",
    "version": "v0.1.0"
  },
  "message": "unable to parse integer: strconv.ParseInt: parsing \"text\": invalid syntax",
  "severity": "ERROR",
  "context": {
    "reportLocation": {
      "filePath": "github.com/TV4/logrus-stackdriver-formatter/example_test.go",
      "lineNumber": 21,
      "functionName": "ExampleLogError"
    }
  }
}

Adding extra context

There are a few fields that can be set to provide extra context for errors which are surfaced in the Error Reporting UI to aid in debugging:

Logrus Field Name	Expected Go Type	Format/Schema
httpRequest	map[string]interface{}	HttpRequestContext
user	string	unrestricted
stack_trace	string	result of runtime.Stack()

If you'd like to add additional context, for example the httpRequest, here's a convenience function for creating a HTTP logger:

func httpLogger(logger *logrus.Logger, r *http.Request) *logrus.Entry {
    return logger.WithFields(logrus.Fields{
        "httpRequest": map[string]interface{}{
            "method":    r.Method,
            "url":       r.URL.String(),
            "userAgent": r.Header.Get("User-Agent"),
            "referrer":  r.Header.Get("Referer"),
        },
    })
}

Then, in your HTTP handler, create a new context logger and all your log entries will have the HTTP request context appended to them:

func handler(w http.ResponseWriter, r *http.Request) {
    httplog := httpLogger(log, r)
    // ...
    httplog.Infof("Logging with HTTP request context")
}

Adding stack traces for errors looks like:

import "runtime/debug"

err := doAThing()
if (err != nil) {
    log.
      WithField("stack_trace", string(debug.Stack())).
      WithError(err).
      Error("doing a thing failed")
}