gcs-ls.go

package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"

	"golang.org/x/net/context"
	"golang.org/x/oauth2/google"
	bigquery "google.golang.org/api/bigquery/v2"
	storage "google.golang.org/api/storage/v1"
)

func BigQueryScope() string {
	return fmt.Sprintf("%s %s %s",
		bigquery.BigqueryScope,
		storage.DevstorageReadOnlyScope,
		"https://www.googleapis.com/auth/userinfo.profile")
}

var (
	bucket     = flag.String("bucket", "kuke", "list buckets name")
	prefix     = flag.String("prefix", "your-object-prefix", "prefix name")
	credential = flag.String("credential", "/path/to/credential", "path to service account credential JSON file")
)

func main() {
	flag.Parse()
	b, err := ioutil.ReadFile(*credential)
	if err != nil {
		log.Fatalf("failed to read %s, %err", *credential, err)
	}
	conf, err := google.JWTConfigFromJSON(b, BigQueryScope())
	if err != nil {
		log.Fatalf("fail %s", err)
	}
	ctx := context.Background()
	client := conf.Client(ctx)

	service, err := storage.New(client)
	if err != nil {
		log.Fatalf("Unable to create Storage service: %v", err)
	}

	list := service.Objects.List(*bucket)
	list.Prefix(*prefix)
	objects, err := list.Do()
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		return
	}

	for _, o := range objects.Items {
		log.Printf("item: %v\n", o)
	}
}