// HandleMeters sends the given values to klog.
func (KlogHandler) HandleMeters(values map[string]float64) {
body, err := json.Marshal(values)
if err != nil {
log.Panicf("unable to marshal meter values: %s", err)
}
klog.KPrint("meter.klog.info", string(body))
}
// Here we'll setup a klog pipeline which will be used to cleanup our output
// stream.
func Example_Pipeline() {
// It's pretty easy to create a printer so, because this is go, let's log to
// a channel.
linesC := make(chan string, 100)
chanPrinter := func(line *klog.Line) {
linesC <- fmt.Sprintf("<%s> %s", line.Key, line.Value)
}
// Next up we'll create a filter stage for our pipeline. FilterIn indicates
// that all matching patterns will be removed from the log stream. Filters
// are applied on the keys and can test for a full, prefix or suffix match.
filter := klog.NewFilter(klog.FilterOut)
filter.AddSuffix("debug")
// Dedup is another useful stage that can be used to avoid spamming the logs
// with duplicated messages. Deduping is done seperately for each key-stream
// and is periodically flushed every second by default.
dedup := klog.NewDedup()
// Now we'll setup our pipeline using the handy klog.Chain function. klog
// also includes a klog.Fork function which can be used to duplicate the
// log-stream down multiple pipelines.
klog.SetPrinter(
klog.Chain(filter,
klog.Chain(dedup,
klog.PrinterFunc(chanPrinter))))
// Time to print stuff out.
klog.KPrint("test.info", "hello")
klog.KPrint("test.info", "hello")
klog.KPrint("test.debug", "whoops")
klog.KPrint("test.info", "hello")
klog.KPrint("test.info", "world")
// Alright, let's read our output.
for i := 0; i < 3; i++ {
fmt.Println(<-linesC)
}
// Output:
// <test.info> hello
// <test.info> hello [2 times]
// <test.info> world
}
// The klogr package provides wrapppers for printer stages which makes them
// accessible from a rest interface using the gorest package.
func Example_REST() {
// Here we create a REST enabled filter which allows us to modify the
// filtering rules of the stage while the program is running.
filter := klog.NewFilterREST("/path/to/filter", klog.FilterIn)
// The ring stage prints to a ring buffer containing the last N elements
// printed. Wrapping this stage in a REST interface allows us to query the
// most recent log elements remotely.
ring := klog.NewRingREST("/path/to/ring", 1000)
// REST enabled stages act like regular stages so they can be used directly
// in a klog pipeline.
klog.SetPrinter(
klog.Chain(filter,
klog.Fork(ring, klog.GetPrinter())))
klog.KPrint("a.b.c", "hello world")
}
// Barebone basic usage example of klog.
func Example_Simple() {
// Default klog printer is a light wrapper around the standard log package
// so we need to modify it a bit to make it work for our example.
log.SetFlags(0)
log.SetOutput(os.Stdout)
log.SetPrefix("klog ")
// KPrint and KPrintf are the only supported print functions where the first
// argument is a key identifying the source of the log message. The key will
// be used in future example to manipulate the log lines as they flow
// through klog.
klog.KPrint("a.b.c", "hello")
klog.KPrintf("c.b.a", "%s", "world")
// Output:
// klog <a.b.c> hello
// klog <c.b.a> world
}