s3manager-web/main.go

package main

import (
	"crypto/tls"
	"embed"
	"fmt"
	"io/fs"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/cloudlena/adapters/logging"
	"github.com/cloudlena/s3manager/internal/app/s3manager"
	"github.com/gorilla/mux"
	"github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
	"github.com/spf13/viper"
)

//go:embed web/template
var templateFS embed.FS

//go:embed web/static
var staticFS embed.FS

type configuration struct {
	Endpoint            string
	UseIam              bool
	IamEndpoint         string
	AccessKeyID         string
	SecretAccessKey     string
	Region              string
	AllowDelete         bool
	ForceDownload       bool
	UseSSL              bool
	SkipSSLVerification bool
	ListRecursive       bool
	Port                string
	Timeout             int32
	SseType             string
	SseKey              string
}

func parseConfiguration() configuration {
	var accessKeyID, secretAccessKey, iamEndpoint string

	viper.AutomaticEnv()

	viper.SetDefault("ENDPOINT", "s3.amazonaws.com")
	endpoint := viper.GetString("ENDPOINT")

	useIam := viper.GetBool("USE_IAM")

	if useIam {
		iamEndpoint = viper.GetString("IAM_ENDPOINT")
	} else {
		accessKeyID = viper.GetString("ACCESS_KEY_ID")
		if len(accessKeyID) == 0 {
			log.Fatal("please provide ACCESS_KEY_ID")
		}

		secretAccessKey = viper.GetString("SECRET_ACCESS_KEY")
		if len(secretAccessKey) == 0 {
			log.Fatal("please provide SECRET_ACCESS_KEY")
		}
	}

	region := viper.GetString("REGION")

	viper.SetDefault("ALLOW_DELETE", true)
	allowDelete := viper.GetBool("ALLOW_DELETE")

	viper.SetDefault("FORCE_DOWNLOAD", true)
	forceDownload := viper.GetBool("FORCE_DOWNLOAD")

	viper.SetDefault("USE_SSL", true)
	useSSL := viper.GetBool("USE_SSL")

	viper.SetDefault("SKIP_SSL_VERIFICATION", false)
	skipSSLVerification := viper.GetBool("SKIP_SSL_VERIFICATION")

	listRecursive := viper.GetBool("LIST_RECURSIVE")

	viper.SetDefault("PORT", "8080")
	port := viper.GetString("PORT")

	viper.SetDefault("TIMEOUT", 600)
	timeout := viper.GetInt32("TIMEOUT")

	viper.SetDefault("SSE_TYPE", "")
	sseType := viper.GetString("SSE_TYPE")
	viper.SetDefault("SSE_KEY", "")
	sseKey := viper.GetString("SSE_KEY")

	return configuration{
		Endpoint:            endpoint,
		UseIam:              useIam,
		IamEndpoint:         iamEndpoint,
		AccessKeyID:         accessKeyID,
		SecretAccessKey:     secretAccessKey,
		Region:              region,
		AllowDelete:         allowDelete,
		ForceDownload:       forceDownload,
		UseSSL:              useSSL,
		SkipSSLVerification: skipSSLVerification,
		ListRecursive:       listRecursive,
		Port:                port,
		Timeout:             timeout,
		SseType:             sseType,
		SseKey:              sseKey,
	}
}

func main() {
	configuration := parseConfiguration()

	sseType := s3manager.SSEType{Type: configuration.SseType, Key: configuration.SseKey}
	serverTimeout := time.Duration(configuration.Timeout) * time.Second

	// Set up templates
	templates, err := fs.Sub(templateFS, "web/template")
	if err != nil {
		log.Fatal(err)
	}
	// Set up statics
	statics, err := fs.Sub(staticFS, "web/static")
	if err != nil {
		log.Fatal(err)
	}

	// Set up S3 client
	opts := &minio.Options{
		Secure: configuration.UseSSL,
	}
	if configuration.UseIam {
		opts.Creds = credentials.NewIAM(configuration.IamEndpoint)
	} else {
		opts.Creds = credentials.NewStaticV4(configuration.AccessKeyID, configuration.SecretAccessKey, "")
	}

	if configuration.Region != "" {
		opts.Region = configuration.Region
	}
	if configuration.UseSSL && configuration.SkipSSLVerification {
		opts.Transport = &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}} //nolint:gosec
	}
	s3, err := minio.New(configuration.Endpoint, opts)
	if err != nil {
		log.Fatalln(fmt.Errorf("error creating s3 client: %w", err))
	}

	// Set up router
	r := mux.NewRouter()
	r.Handle("/", http.RedirectHandler("/buckets", http.StatusPermanentRedirect)).Methods(http.MethodGet)
	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.FS(statics)))).Methods(http.MethodGet)
	r.Handle("/buckets", s3manager.HandleBucketsView(s3, templates, configuration.AllowDelete)).Methods(http.MethodGet)
	r.PathPrefix("/buckets/").Handler(s3manager.HandleBucketView(s3, templates, configuration.AllowDelete, configuration.ListRecursive)).Methods(http.MethodGet)
	r.Handle("/api/buckets", s3manager.HandleCreateBucket(s3)).Methods(http.MethodPost)
	if configuration.AllowDelete {
		r.Handle("/api/buckets/{bucketName}", s3manager.HandleDeleteBucket(s3)).Methods(http.MethodDelete)
	}
	r.Handle("/api/buckets/{bucketName}/objects", s3manager.HandleCreateObject(s3, sseType)).Methods(http.MethodPost)
	r.Handle("/api/buckets/{bucketName}/objects/{objectName:.*}/url", s3manager.HandleGenerateUrl(s3)).Methods(http.MethodGet)
	r.Handle("/api/buckets/{bucketName}/objects/{objectName:.*}", s3manager.HandleGetObject(s3, configuration.ForceDownload)).Methods(http.MethodGet)
	if configuration.AllowDelete {
		r.Handle("/api/buckets/{bucketName}/objects/{objectName:.*}", s3manager.HandleDeleteObject(s3)).Methods(http.MethodDelete)
	}

	lr := logging.Handler(os.Stdout)(r)
	srv := &http.Server{
		Addr:         ":" + configuration.Port,
		Handler:      lr,
		ReadTimeout:  serverTimeout,
		WriteTimeout: serverTimeout,
	}
	log.Fatal(srv.ListenAndServe())
}