log/experimental_level: package documentation
Peter Bourgon
7 years ago
| 0 | // Package level is an EXPERIMENTAL levelled logging package. The API will | |
| 1 | // definitely have breaking changes and may be deleted altogether. Be warned! | |
| 2 | // | |
| 3 | // To use the level package, create a logger as per normal in your func main, | |
| 4 | // and wrap it with level.New. | |
| 5 | // | |
| 6 | // var logger log.Logger | |
| 7 | // logger = log.NewLogfmtLogger(os.Stderr) | |
| 8 | // logger = level.New(logger, level.Config{Allowed: level.AllowInfoAndAbove}) // <-- | |
| 9 | // logger = log.NewContext(logger).With("ts", log.DefaultTimestampUTC) | |
| 10 | // | |
| 11 | // Then, at the callsites, use one of the level.Debug, Info, Warn, or Error | |
| 12 | // helper methods to emit leveled log events. | |
| 13 | // | |
| 14 | // logger.Log("foo", "bar") // as normal, no level | |
| 15 | // level.Debug(logger).Log("request_id", reqID, "trace_data", trace.Get()) | |
| 16 | // if value > 100 { | |
| 17 | // level.Error(logger).Log("value", value) | |
| 18 | // } | |
| 19 | // | |
| 20 | // The leveled logger allows precise control over what should happen if a log | |
| 21 | // event is emitted without a level key, or if a squelched level is used. Check | |
| 22 | // the Config struct for details. And, you can easily use non-default level | |
| 23 | // values: create new string constants for whatever you want to change, pass | |
| 24 | // them explicitly to the Config struct, and write your own level.Foo-style | |
| 25 | // helper methods. | |
| 26 | package level |