How can I implement custom log hooks in Logrus?

How can I implement custom log hooks in Logrus?

To implement custom log hooks in Logrus, you need to create a struct that implements the logrus.Hook interface.

Can you give me an example of a custom hook?

Sure! Here's a simple example of a custom hook that logs to a file:

type FileHook struct {
    filename string
}

func (h *FileHook) Levels() []logrus.Level {
    return logrus.AllLevels
}

func (h *FileHook) Fire(entry *logrus.Entry) error {
    f, err := os.OpenFile(h.filename, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
    if err != nil {
        return err
    }
    defer f.Close()
    log := logrus.New()
    log.SetOutput(f)
    log.WithFields(entry.Data).Log(entry.Level, entry.Message)
    return nil
}

You can then add this hook to your logger using logrus.AddHook(&FileHook{filename: "log.txt"}).

What are some common use cases for custom log hooks?

Common use cases include sending logs to external services, filtering logs based on severity, or formatting logs for specific outputs.

How do I test my custom log hook?

You can test your custom log hook by creating a test logger, triggering log events, and verifying the output in your desired destination.