feat: initial version

cmd/service/service.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+
+	"github.com/alecthomas/kong"
+	"github.com/apex/log"
+	"github.com/apex/log/handlers/json"
+
+	"gitlab.com/unboundsoftware/s3uploader/server"
+	"gitlab.com/unboundsoftware/s3uploader/storage"
+)
+
+var CLI struct {
+	Port      int    `name:"port" env:"PORT" help:"Port which the service listens to" default:"80"`
+	Bucket    string `name:"bucket" env:"BUCKET" help:"The AWS S3 bucket where the uploaded objects should be stored" required:"true"`
+	ReturnURL string `name:"return-url" env:"RETURN_URL" help:"Base-url to be prepended to all returned locations" required:"true"`
+}
+
+func main() {
+	_ = kong.Parse(&CLI)
+	log.SetHandler(json.New(os.Stdout))
+	logger := log.WithField("service", "s3uploader")
+
+	if err := start(logger); err != nil {
+		logger.WithError(err).Error("process error")
+	}
+}
+
+func start(logger log.Interface) error {
+	rootCtx, rootCancel := context.WithCancel(context.Background())
+	defer rootCancel()
+
+	s3, err := storage.New(CLI.Bucket)
+	if err != nil {
+		return fmt.Errorf("storage failed: %w", err)
+	}
+	srv := server.New(s3, CLI.ReturnURL, logger)
+	httpSrvAddr := fmt.Sprintf(":%d", CLI.Port)
+	httpSrv := &http.Server{Addr: httpSrvAddr, Handler: srv}
+
+	wg := sync.WaitGroup{}
+
+	sigint := make(chan os.Signal, 1)
+	signal.Notify(sigint, os.Interrupt, syscall.SIGTERM)
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		sig := <-sigint
+		if sig != nil {
+			// In case our shutdown logic is broken/incomplete we reset signal
+			// handlers so next signal goes to go itself. Go is more aggressive when
+			// shutting down goroutines
+			signal.Reset(os.Interrupt, syscall.SIGTERM)
+			logger.Info("Got shutdown signal..")
+			rootCancel()
+		}
+	}()
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		<-rootCtx.Done()
+
+		close(sigint)
+
+		ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+		defer cancel()
+		err := httpSrv.Shutdown(ctx)
+		logger.WithError(err).Info("Shutdown of HTTP server complete")
+	}()
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		logger.Info(fmt.Sprintf("Serving HTTP API on %s", httpSrvAddr))
+		err := httpSrv.ListenAndServe()
+		if err != nil && !errors.Is(err, http.ErrServerClosed) {
+			logger.WithError(err).Error("HTTP server failed")
+			rootCancel()
+		}
+	}()
+
+	wg.Wait()
+
+	return nil
+}