Mainflux.mainflux/cmd/mongodb-reader/main.go

135 lines
3.4 KiB
Go

//
// Copyright (c) 2018
// Mainflux
//
// SPDX-License-Identifier: Apache-2.0
//
package main
import (
"context"
"fmt"
"net/http"
"os"
"os/signal"
"syscall"
kitprometheus "github.com/go-kit/kit/metrics/prometheus"
"github.com/mainflux/mainflux"
log "github.com/mainflux/mainflux/logger"
"github.com/mainflux/mainflux/readers"
"github.com/mainflux/mainflux/readers/api"
"github.com/mainflux/mainflux/readers/mongodb"
thingsapi "github.com/mainflux/mainflux/things/api/grpc"
"github.com/mongodb/mongo-go-driver/mongo"
stdprometheus "github.com/prometheus/client_golang/prometheus"
"google.golang.org/grpc"
)
const (
defThingsURL = "localhost:8181"
defPort = "8180"
defDBName = "mainflux"
defDBHost = "localhost"
defDBPort = "27017"
envThingsURL = "MF_THINGS_URL"
envPort = "MF_MONGO_READER_PORT"
envDBName = "MF_MONGO_READER_DB_NAME"
envDBHost = "MF_MONGO_READER_DB_HOST"
envDBPort = "MF_MONGO_READER_DB_PORT"
)
type config struct {
thingsURL string
port string
dbName string
dbHost string
dbPort string
}
func main() {
cfg := loadConfigs()
logger := log.New(os.Stdout)
conn := connectToThings(cfg.thingsURL, logger)
defer conn.Close()
tc := thingsapi.NewClient(conn)
db := connectToMongoDB(cfg.dbHost, cfg.dbPort, cfg.dbName, logger)
repo := newService(db, logger)
errs := make(chan error, 2)
go func() {
c := make(chan os.Signal)
signal.Notify(c, syscall.SIGINT)
errs <- fmt.Errorf("%s", <-c)
}()
go startHTTPServer(repo, tc, cfg.port, logger, errs)
err := <-errs
logger.Error(fmt.Sprintf("MongoDB reader service terminated: %s", err))
}
func loadConfigs() config {
return config{
thingsURL: mainflux.Env(envThingsURL, defThingsURL),
port: mainflux.Env(envPort, defPort),
dbName: mainflux.Env(envDBName, defDBName),
dbHost: mainflux.Env(envDBHost, defDBHost),
dbPort: mainflux.Env(envDBPort, defDBPort),
}
}
func connectToMongoDB(host, port, name string, logger log.Logger) *mongo.Database {
client, err := mongo.Connect(context.Background(), fmt.Sprintf("mongodb://%s:%s", host, port), nil)
if err != nil {
logger.Error(fmt.Sprintf("Failed to connect to database: %s", err))
os.Exit(1)
}
return client.Database(name)
}
func connectToThings(url string, logger log.Logger) *grpc.ClientConn {
conn, err := grpc.Dial(url, grpc.WithInsecure())
if err != nil {
logger.Error(fmt.Sprintf("Failed to connect to things service: %s", err))
os.Exit(1)
}
return conn
}
func newService(db *mongo.Database, logger log.Logger) readers.MessageRepository {
repo := mongodb.New(db)
repo = api.LoggingMiddleware(repo, logger)
repo = api.MetricsMiddleware(
repo,
kitprometheus.NewCounterFrom(stdprometheus.CounterOpts{
Namespace: "mongodb",
Subsystem: "message_reader",
Name: "request_count",
Help: "Number of requests received.",
}, []string{"method"}),
kitprometheus.NewSummaryFrom(stdprometheus.SummaryOpts{
Namespace: "mongodb",
Subsystem: "message_reader",
Name: "request_latency_microseconds",
Help: "Total duration of requests in microseconds.",
}, []string{"method"}),
)
return repo
}
func startHTTPServer(repo readers.MessageRepository, tc mainflux.ThingsServiceClient, port string, logger log.Logger, errs chan error) {
p := fmt.Sprintf(":%s", port)
logger.Info(fmt.Sprintf("Mongo reader service started, exposed port %s", port))
errs <- http.ListenAndServe(p, api.MakeHandler(repo, tc, "cassandra-reader"))
}