vendor/github.com/hashicorp/logutils/README.md

   1 # logutils
   2
   3 logutils is a Go package that augments the standard library "log" package
   4 to make logging a bit more modern, without fragmenting the Go ecosystem
   5 with new logging packages.
   6
   7 ## The simplest thing that could possibly work
   8
   9 Presumably your application already uses the default `log` package. To switch, you'll want your code to look like the following:
  10
  11 ```go
  12 package main
  13
  14 import (
  15         "log"
  16         "os"
  17
  18         "github.com/hashicorp/logutils"
  19 )
  20
  21 func main() {
  22         filter := &logutils.LevelFilter{
  23                 Levels: []logutils.LogLevel{"DEBUG", "WARN", "ERROR"},
  24                 MinLevel: logutils.LogLevel("WARN"),
  25                 Writer: os.Stderr,
  26         }
  27         log.SetOutput(filter)
  28
  29         log.Print("[DEBUG] Debugging") // this will not print
  30         log.Print("[WARN] Warning") // this will
  31         log.Print("[ERROR] Erring") // and so will this
  32         log.Print("Message I haven't updated") // and so will this
  33 }
  34 ```
  35
  36 This logs to standard error exactly like go's standard logger. Any log messages you haven't converted to have a level will continue to print as before.