Mainflux.mainflux/cmd/normalizer/main.go

99 lines
2.3 KiB
Go

// Copyright (c) Mainflux
// SPDX-License-Identifier: Apache-2.0
package main
import (
"fmt"
"log"
"net/http"
"os"
"os/signal"
"syscall"
"github.com/mainflux/mainflux"
"github.com/mainflux/mainflux/logger"
"github.com/mainflux/mainflux/normalizer"
"github.com/mainflux/mainflux/normalizer/api"
"github.com/mainflux/mainflux/normalizer/nats"
broker "github.com/nats-io/go-nats"
kitprometheus "github.com/go-kit/kit/metrics/prometheus"
stdprometheus "github.com/prometheus/client_golang/prometheus"
)
const (
defNatsURL string = broker.DefaultURL
defLogLevel string = "error"
defPort string = "8180"
envNatsURL string = "MF_NATS_URL"
envLogLevel string = "MF_NORMALIZER_LOG_LEVEL"
envPort string = "MF_NORMALIZER_PORT"
)
type config struct {
NatsURL string
LogLevel string
Port string
}
func main() {
cfg := loadConfig()
logger, err := logger.New(os.Stdout, cfg.LogLevel)
if err != nil {
log.Fatalf(err.Error())
}
nc, err := broker.Connect(cfg.NatsURL)
if err != nil {
logger.Error(fmt.Sprintf("Failed to connect to NATS: %s", err))
os.Exit(1)
}
defer nc.Close()
svc := normalizer.New()
svc = api.LoggingMiddleware(svc, logger)
svc = api.MetricsMiddleware(
svc,
kitprometheus.NewCounterFrom(stdprometheus.CounterOpts{
Namespace: "normalizer",
Subsystem: "api",
Name: "request_count",
Help: "Number of requests received.",
}, []string{"method"}),
kitprometheus.NewSummaryFrom(stdprometheus.SummaryOpts{
Namespace: "normalizer",
Subsystem: "api",
Name: "request_latency_microseconds",
Help: "Total duration of requests in microseconds.",
}, []string{"method"}),
)
errs := make(chan error, 2)
go func() {
p := fmt.Sprintf(":%s", cfg.Port)
logger.Info(fmt.Sprintf("Normalizer service started, exposed port %s", cfg.Port))
errs <- http.ListenAndServe(p, api.MakeHandler())
}()
go func() {
c := make(chan os.Signal)
signal.Notify(c, syscall.SIGINT)
errs <- fmt.Errorf("%s", <-c)
}()
nats.Subscribe(svc, nc, logger)
err = <-errs
logger.Error(fmt.Sprintf("Normalizer service terminated: %s", err))
}
func loadConfig() config {
return config{
NatsURL: mainflux.Env(envNatsURL, defNatsURL),
LogLevel: mainflux.Env(envLogLevel, defLogLevel),
Port: mainflux.Env(envPort, defPort),
}
}