Package list golang-github-go-kit-kit / 1b5215d
log: Explain why Logger.Log returns an error and how to work with it. Chris Hines 4 years ago
1 changed file(s) with 23 addition(s) and 0 deletion(s). Raw diff Collapse all Expand all
8989 // handled atomically within the wrapped logger, but it typically serializes
9090 // both the formatting and output logic. Use a SyncLogger if the formatting
9191 // logger may perform multiple writes per log event.
92 //
93 // Error Handling
94 //
95 // This package relies on the practice of wrapping or decorating loggers with
96 // other loggers to provide composable pieces of functionality. It also means
97 // that Logger.Log must return an error because some
98 // implementations—especially those that output log data to an io.Writer—may
99 // encounter errors that cannot be handled locally. This in turn means that
100 // Loggers that wrap other loggers should return errors from the wrapped
101 // logger up the stack.
102 //
103 // Fortunately, the decorator pattern also provides a way to avoid the
104 // necessity to check for errors every time an application calls Logger.Log.
105 // An application required to panic whenever its Logger encounters
106 // an error could initialize its logger as follows.
107 //
108 // fmtlogger := log.NewLogfmtLogger(log.NewSyncWriter(os.Stdout))
109 // logger := log.LoggerFunc(func(keyvals ...interface{}) error {
110 // if err := fmtlogger.Log(keyvals...); err != nil {
111 // panic(err)
112 // }
113 // return nil
114 // })
92115 package log