forked from mirror/logrus
68 lines
2.0 KiB
Markdown
68 lines
2.0 KiB
Markdown
# Logrus
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Logrus is a simple, opinionated logging package for Go. It has three debugging
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levels:
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* `LevelDebug`: Debugging, usually turned off for deploys.
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* `LevelInfo`: Info, useful for monitoring in production.
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* `LevelWarning`: Warnings that should definitely be noted. These are sent to
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`airbrake`.
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* `LevelFatal`: Fatal messages that causes the application to crash. These are
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sent to `airbrake`.
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## Usage
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The global logging level is set by: `logrus.Level = logrus.{LevelDebug,LevelWarning,LevelFatal}`.
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Note that for `airbrake` to work, `airbrake.Endpoint` and `airbrake.ApiKey`
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should be set.
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There is a global logger, which new loggers inherit their settings from when
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created (see example below), such as the place to redirect output. Logging can
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be done with the global logging module:
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```go
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logrus.Debug("Something debugworthy happened: %s", importantStuff")
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logrus.Info("Something infoworthy happened: %s", importantStuff")
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logrus.Warning("Something bad happened: %s", importantStuff")
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// Reports to Airbrake
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logrus.Fatal("Something fatal happened: %s", importantStuff")
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// Reports to Airbrake
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// Then exits
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```
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Types are encouraged to include their own logging object. This allows to set a
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context dependent prefix to know where a certain message is coming from, without
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cluttering every single message with this.
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```go
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type Walrus struct {
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TuskSize uint64
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Sex bool
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logger logrus.Logger
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}
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func NewWalrus(tuskSize uint64, sex bool) *Walrus {
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return &Walrus{
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TuskSize: tuskSize,
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Sex: bool,
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logger: logrus.NewLogger("Walrus"),
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}
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}
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func (walrus *Walrus) Mate(partner *Walrus) error {
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if walrus.Sex == partner.Sex {
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return errors.New("Incompatible mating partner.")
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}
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walrus.logger.Info("Walrus with tusk sizes %d and %d are mating!", walrus.TuskSize, partner.TuskSize)
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// Generates a logging message: <timestamp> [Info] [Walrus] Walrus with tusk sizes <int> and <int> are mating!
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// Walrus mating happens here
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return nil
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}
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```
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