func instrument(requests metrics.Counter, duration metrics.TimeHistogram) func(Add) Add {
return func(next Add) Add {
return func(ctx context.Context, a, b int64) int64 {
defer func(begin time.Time) {
requests.Add(1)
duration.Observe(time.Since(begin))
}(time.Now())
return next(ctx, a, b)
}
}
}
// EndpointInstrumentingMiddleware returns an endpoint middleware that records
// the duration of each invocation to the passed histogram. The middleware adds
// a single field: "success", which is "true" if no error is returned, and
// "false" otherwise.
func EndpointInstrumentingMiddleware(duration metrics.TimeHistogram) endpoint.Middleware {
return func(next endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (response interface{}, err error) {
defer func(begin time.Time) {
f := metrics.Field{Key: "success", Value: fmt.Sprint(err == nil)}
duration.With(f).Observe(time.Since(begin))
}(time.Now())
return next(ctx, request)
}
}
}
func main() {
var (
debugAddr = flag.String("debug.addr", ":8080", "Debug and metrics listen address")
httpAddr = flag.String("http.addr", ":8081", "HTTP listen address")
grpcAddr = flag.String("grpc.addr", ":8082", "gRPC (HTTP) listen address")
thriftAddr = flag.String("thrift.addr", ":8083", "Thrift listen address")
thriftProtocol = flag.String("thrift.protocol", "binary", "binary, compact, json, simplejson")
thriftBufferSize = flag.Int("thrift.buffer.size", 0, "0 for unbuffered")
thriftFramed = flag.Bool("thrift.framed", false, "true to enable framing")
zipkinAddr = flag.String("zipkin.addr", "", "Enable Zipkin tracing via a Kafka server host:port")
appdashAddr = flag.String("appdash.addr", "", "Enable Appdash tracing via an Appdash server host:port")
lightstepToken = flag.String("lightstep.token", "", "Enable LightStep tracing via a LightStep access token")
)
flag.Parse()
// Logging domain.
var logger log.Logger
{
logger = log.NewLogfmtLogger(os.Stdout)
logger = log.NewContext(logger).With("ts", log.DefaultTimestampUTC)
logger = log.NewContext(logger).With("caller", log.DefaultCaller)
}
logger.Log("msg", "hello")
defer logger.Log("msg", "goodbye")
// Metrics domain.
var ints, chars metrics.Counter
{
// Business level metrics.
ints = prometheus.NewCounter(stdprometheus.CounterOpts{
Namespace: "addsvc",
Name: "integers_summed",
Help: "Total count of integers summed via the Sum method.",
}, []string{})
chars = prometheus.NewCounter(stdprometheus.CounterOpts{
Namespace: "addsvc",
Name: "characters_concatenated",
Help: "Total count of characters concatenated via the Concat method.",
}, []string{})
}
var duration metrics.TimeHistogram
{
// Transport level metrics.
duration = metrics.NewTimeHistogram(time.Nanosecond, prometheus.NewSummary(stdprometheus.SummaryOpts{
Namespace: "addsvc",
Name: "request_duration_ns",
Help: "Request duration in nanoseconds.",
}, []string{"method", "success"}))
}
// Tracing domain.
var tracer stdopentracing.Tracer
{
if *zipkinAddr != "" {
logger := log.NewContext(logger).With("tracer", "Zipkin")
logger.Log("addr", *zipkinAddr)
collector, err := zipkin.NewKafkaCollector(
strings.Split(*zipkinAddr, ","),
zipkin.KafkaLogger(logger),
)
if err != nil {
logger.Log("err", err)
os.Exit(1)
}
tracer, err = zipkin.NewTracer(
zipkin.NewRecorder(collector, false, "localhost:80", "addsvc"),
)
if err != nil {
logger.Log("err", err)
os.Exit(1)
}
} else if *appdashAddr != "" {
logger := log.NewContext(logger).With("tracer", "Appdash")
logger.Log("addr", *appdashAddr)
tracer = appdashot.NewTracer(appdash.NewRemoteCollector(*appdashAddr))
} else if *lightstepToken != "" {
logger := log.NewContext(logger).With("tracer", "LightStep")
logger.Log() // probably don't want to print out the token :)
tracer = lightstep.NewTracer(lightstep.Options{
AccessToken: *lightstepToken,
})
defer lightstep.FlushLightStepTracer(tracer)
} else {
logger := log.NewContext(logger).With("tracer", "none")
logger.Log()
tracer = stdopentracing.GlobalTracer() // no-op
}
}
// Business domain.
var service addsvc.Service
{
service = addsvc.NewBasicService()
service = addsvc.ServiceLoggingMiddleware(logger)(service)
service = addsvc.ServiceInstrumentingMiddleware(ints, chars)(service)
}
// Endpoint domain.
var sumEndpoint endpoint.Endpoint
{
sumDuration := duration.With(metrics.Field{Key: "method", Value: "Sum"})
sumLogger := log.NewContext(logger).With("method", "Sum")
sumEndpoint = addsvc.MakeSumEndpoint(service)
sumEndpoint = opentracing.TraceServer(tracer, "Sum")(sumEndpoint)
sumEndpoint = addsvc.EndpointInstrumentingMiddleware(sumDuration)(sumEndpoint)
sumEndpoint = addsvc.EndpointLoggingMiddleware(sumLogger)(sumEndpoint)
}
var concatEndpoint endpoint.Endpoint
{
concatDuration := duration.With(metrics.Field{Key: "method", Value: "Concat"})
concatLogger := log.NewContext(logger).With("method", "Concat")
concatEndpoint = addsvc.MakeConcatEndpoint(service)
concatEndpoint = opentracing.TraceServer(tracer, "Concat")(concatEndpoint)
concatEndpoint = addsvc.EndpointInstrumentingMiddleware(concatDuration)(concatEndpoint)
concatEndpoint = addsvc.EndpointLoggingMiddleware(concatLogger)(concatEndpoint)
}
endpoints := addsvc.Endpoints{
SumEndpoint: sumEndpoint,
ConcatEndpoint: concatEndpoint,
}
// Mechanical domain.
errc := make(chan error)
ctx := context.Background()
// Interrupt handler.
go func() {
c := make(chan os.Signal, 1)
signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
errc <- fmt.Errorf("%s", <-c)
}()
// Debug listener.
go func() {
logger := log.NewContext(logger).With("transport", "debug")
m := http.NewServeMux()
m.Handle("/debug/pprof/", http.HandlerFunc(pprof.Index))
m.Handle("/debug/pprof/cmdline", http.HandlerFunc(pprof.Cmdline))
m.Handle("/debug/pprof/profile", http.HandlerFunc(pprof.Profile))
m.Handle("/debug/pprof/symbol", http.HandlerFunc(pprof.Symbol))
m.Handle("/debug/pprof/trace", http.HandlerFunc(pprof.Trace))
m.Handle("/metrics", stdprometheus.Handler())
logger.Log("addr", *debugAddr)
errc <- http.ListenAndServe(*debugAddr, m)
}()
// HTTP transport.
go func() {
logger := log.NewContext(logger).With("transport", "HTTP")
h := addsvc.MakeHTTPHandler(ctx, endpoints, tracer, logger)
logger.Log("addr", *httpAddr)
errc <- http.ListenAndServe(*httpAddr, h)
}()
// gRPC transport.
go func() {
logger := log.NewContext(logger).With("transport", "gRPC")
ln, err := net.Listen("tcp", *grpcAddr)
if err != nil {
errc <- err
return
}
srv := addsvc.MakeGRPCServer(ctx, endpoints, tracer, logger)
s := grpc.NewServer()
pb.RegisterAddServer(s, srv)
logger.Log("addr", *grpcAddr)
errc <- s.Serve(ln)
}()
// Thrift transport.
go func() {
logger := log.NewContext(logger).With("transport", "Thrift")
var protocolFactory thrift.TProtocolFactory
switch *thriftProtocol {
case "binary":
protocolFactory = thrift.NewTBinaryProtocolFactoryDefault()
case "compact":
protocolFactory = thrift.NewTCompactProtocolFactory()
case "json":
protocolFactory = thrift.NewTJSONProtocolFactory()
case "simplejson":
protocolFactory = thrift.NewTSimpleJSONProtocolFactory()
default:
errc <- fmt.Errorf("invalid Thrift protocol %q", *thriftProtocol)
return
}
var transportFactory thrift.TTransportFactory
if *thriftBufferSize > 0 {
transportFactory = thrift.NewTBufferedTransportFactory(*thriftBufferSize)
} else {
transportFactory = thrift.NewTTransportFactory()
}
if *thriftFramed {
transportFactory = thrift.NewTFramedTransportFactory(transportFactory)
}
transport, err := thrift.NewTServerSocket(*thriftAddr)
if err != nil {
errc <- err
return
}
logger.Log("addr", *thriftAddr)
errc <- thrift.NewTSimpleServer4(
thriftadd.NewAddServiceProcessor(addsvc.MakeThriftHandler(ctx, endpoints)),
transport,
transportFactory,
protocolFactory,
).Serve()
}()
// Run!
logger.Log("exit", <-errc)
}