teltech/logger

Super simple structured logging mechanism for Go projects with Stackdriver format compatibility

Installation

go get -u github.com/BSP-Mosaic/teltech-logger

Deployment Instructions

Use the deploy.sh script to deploy your Go project to the Artifactory go-local repository. Here's how you can do it:

Deploy Using Existing Module Definition

If your project includes a go.mod file with a defined module name, deploy by specifying only the version:

./deploy.sh v1.0.0

Deploy with Custom Module Name

If your project does not have a go.mod, use:

./deploy.sh bendingspoons.com/logger v1.0.0

Ensure that ARTIFACTORY_ACCESS_TOKEN, ARTIFACTORY_URL, and ARTIFACTORY_USERNAME are present in the environment variables before using the script.

Usage

package main

import (
    "github.com/BSP-Mosaic/teltech-logger"
)

// There should be a LOG_LEVEL environment variable set, which is read by the library
// If no value is set, the default LOG_LEVEL will be INFO

func main() {
    // Stackdriver requires a project name and version to be set. Use your environment for these values.
    // SERVICE should be your GCP project-id, e.g. my-gce-project-id
    // VERSION is an arbitrary value
    log := logger.New()

    // You can also initialize the logger with a context, the values will persisted throughout the scope of the logger instance
    log = logger.New().With(logger.Fields{
        "user":   "+1234567890",
        "action": "create-account",
    })

    param := "something useful here"

    // Log a DEBUG message, only visible in when LOG_LEVEL is set to DEBUG
    log.With(logger.Fields{"key": "val", "something": true}).Debug("debug message goes here")
    log.With(logger.Fields{"key": "val"}).Debugf("debug message with %s", param)

    // Log an INFO message, should be used for metrics as well
    log.Info("CUSTOM_METRIC")
    log.With(logger.Fields{"key": "val", "names": []string{"Mauricio", "Manuel"}}).Info("info message goes here")
    log.With(logger.Fields{"key": "val"}).Infof("info message with %s", param)

    // Log a WARN message
    log.With(logger.Fields{"key": "val"}).Warn("warn message goes here")
    log.With(logger.Fields{"key": "val"}).Warnf("warn message with %s", param)

    // Error() prints the stacktrace as part of the payload for each entry and sends the
    // data to Stackdriver Error Reporting service
    log.With(logger.Fields{"key": "val"}).Error("error message goes here")
    log.With(logger.Fields{"key": "val"}).Errorf("error message with %s", param)
}

Output

The errors require a specific JSON format for them to be ingested and processed by Google Cloud Platform Stackdriver Logging and Error Reporting. See: https://cloud.google.com/error-reporting/docs/formatting-error-messages. The resulting output has the following format, optional fields are... well, optional:

{
  "severity": "ERROR",
  "eventTime": "2017-04-26T02:29:33-04:00",
  "message": "An error just happened!",
  "serviceContext": {
    "service": "my-gce-project-id",
    "version": "1.0"
  },
  "context": {
    "data": {
      "clientIP": "127.0.0.1",
      "userAgent": "Mosaic 1.0"
    },
    "reportLocation": {
      "filePath": "/Users/mc/Documents/src/github.com/macuenca/apex/mauricio.go",
      "functionName": "unknown",
      "lineNumber": 15
    }
  },
  "stacktrace": "goroutine 1 [running]:main.main()\n\t/github.com/macuenca/mauricio.go:15 +0x1a9\n"
}