Files
geo-service/main.go
T

110 lines
2.7 KiB
Go

package main
import (
"context"
"encoding/json"
"fmt"
"github.com/caarlos0/env"
"github.com/nats-io/go-nats-streaming"
"googlemaps.github.io/maps"
"log"
"os"
"os/signal"
)
type config struct {
MapsApiKey string `env:"MAPS_API_KEY"`
NATSUrl string `env:"NATS_URL" envDefault:"nats://nats:4222"`
}
type event struct {
Name string `json:"name"`
City string `json:"city"`
Municipality string `json:"municipality"`
State string `json:"state"`
Created string `json:"created"`
}
type location struct {
Name string `json:"name"`
City string `json:"city"`
Municipality string `json:"municipality"`
State string `json:"state"`
Lat float64 `json:"lat"`
Long float64 `json:"long"`
}
func main() {
cfg := config{}
err := env.Parse(&cfg)
if err != nil {
fmt.Printf("%+v\n", err)
}
fmt.Printf("%+v\n", cfg)
clusterID := "stan"
clientID := "geo-service"
c, err := maps.NewClient(maps.WithAPIKey(cfg.MapsApiKey))
if err != nil {
log.Fatalf("fatal error: %s", err)
}
sc, err := stan.Connect(clusterID, clientID, stan.NatsURL(cfg.NATSUrl),
stan.SetConnectionLostHandler(func(_ stan.Conn, reason error) {
log.Fatalf("Connection lost, reason: %v", reason)
}))
if err != nil {
log.Fatalf("Can't connect: %v.\nMake sure a NATS Streaming Server is running at: %s", err, cfg.NATSUrl)
}
log.Printf("Connected to %s clusterID: [%s] clientID: [%s]\n", cfg.NATSUrl, clusterID, clientID)
mcb := func(msg *stan.Msg) {
e := event{}
if err := json.Unmarshal(msg.Data, &e); err != nil {
panic(err)
}
r := &maps.GeocodingRequest{
Address: fmt.Sprintf("%s,%s,%s,%s", e.Name, e.City, e.Municipality, e.State),
}
if result, err := c.Geocode(context.Background(), r); err != nil {
log.Fatalf("fatal error: %s", err)
} else {
l := location{
Name: e.Name,
City: e.City,
Municipality: e.Municipality,
State: e.State,
Lat: result[0].Geometry.Location.Lat,
Long: result[0].Geometry.Location.Lng,
}
if response, err := json.Marshal(l); err != nil {
log.Fatalf("fatal error: %s", err)
} else {
if err := sc.Publish("DanceHall.Location", response); err != nil {
log.Fatalf("fatal error: %s", err)
}
}
}
}
if _, err := sc.QueueSubscribe("DanceHall.Created", "geo-service", mcb, stan.StartWithLastReceived(), stan.DurableName("geo-service")); err != nil {
_ = sc.Close()
log.Fatal(err)
}
signalChan := make(chan os.Signal, 1)
cleanupDone := make(chan bool)
signal.Notify(signalChan, os.Interrupt)
go func() {
for range signalChan {
fmt.Printf("\nReceived an interrupt, unsubscribing and closing connection...\n\n")
// Do not unsubscribe a durable on exit, except if asked to.
_ = sc.Close()
cleanupDone <- true
}
}()
<-cleanupDone
}