main.go

package main

import (
	"flag"
	"log"
	"net/http"
	"os"
	"time"

	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

func main() {
	addr := flag.String("addr", ":10000", "service addr")
	influxdbURL := flag.String("influxdb.url", getenv("INFLUXDB_URL", "http://localhost:8086"), "influxdb url")
	influxdbToken := flag.String("influxdb.token", getenv("INFLUXDB_TOKEN", ""), "influxdb token")
	influxdbBucket := flag.String("influxdb.bucket", getenv("INFLUXDB_BUCKET", ""), "influxdb bucket")
	influxdbTimeout := flag.Duration("influxdb.timeout", mustParseDuration(getenv("INFLUXDB_TIMEOUT", "15m")), "influxdb client timeout")
	rabbitmqURL := flag.String("rabbitmq.url", getenv("RABBITMQ_URL", ""), "rabbitmq url")
	streamHeartbeatDuration := flag.Duration("stream.heartbeat-duration", mustParseDuration(getenv("STREAM_HEARTBEAT_DURATION", "15s")), "stream heartbeat duration")
	flag.Parse()

	log.Printf("connecting to influxdb at %s", *influxdbURL)
	client := influxdb2.NewClient(*influxdbURL, *influxdbToken)
	defer client.Close()

	// TODO figure out reasonable timeout on potentially large result sets
	client.Options().HTTPClient().Timeout = *influxdbTimeout

	querySvc := NewService(&ServiceConfig{
		Backend: &InfluxBackend{
			Client: client,
			Org:    "waggle",
			Bucket: *influxdbBucket,
		},
	})

	streamSvc := &StreamService{
		RabbitMQURL:       *rabbitmqURL,
		HeartbeatDuration: *streamHeartbeatDuration,
	}

	// NOTE temporarily redirecting to sage docs. can change to something better later.
	http.Handle("/", http.RedirectHandler("https://docs.waggle-edge.ai/docs/tutorials/accessing-data", http.StatusTemporaryRedirect))
	http.Handle("/metrics", promhttp.Handler())
	http.Handle("/api/v1/query", querySvc)
	http.Handle("/api/v0/stream", streamSvc)

	log.Printf("service listening on %s", *addr)
	if err := http.ListenAndServe(*addr, nil); err != nil {
		log.Fatal(err)
	}
}

func getenv(key string, fallback string) string {
	if s, ok := os.LookupEnv(key); ok {
		return s
	}
	return fallback
}

func mustParseDuration(s string) time.Duration {
	d, err := time.ParseDuration(s)
	if err != nil {
		panic(err)
	}
	return d
}