feat: s3 download

scripts/test_s3_simple.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"log"
+	"os"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/config"
+	"github.com/aws/aws-sdk-go-v2/service/s3"
+)
+
+func main() {
+	ctx := context.Background()
+
+	// Create AWS config with anonymous credentials
+	cfg, err := config.LoadDefaultConfig(ctx,
+		config.WithRegion("us-east-1"),
+		config.WithCredentialsProvider(aws.AnonymousCredentials{}),
+	)
+	if err != nil {
+		log.Fatalf("Failed to load config: %v", err)
+	}
+
+	client := s3.NewFromConfig(cfg)
+
+	// Try to download a single file
+	bucket := "noaa-gfs-bdp-pds"
+	key := "gfs.20251020/00/atmos/gfs.t00z.pgrb2.0p50.f000"
+
+	fmt.Printf("Downloading: s3://%s/%s\n", bucket, key)
+
+	input := &s3.GetObjectInput{
+		Bucket: aws.String(bucket),
+		Key:    aws.String(key),
+	}
+
+	result, err := client.GetObject(ctx, input)
+	if err != nil {
+		log.Fatalf("Failed to get object: %v", err)
+	}
+	defer result.Body.Close()
+
+	// Create output file
+	outFile := "/tmp/test_grib.part"
+	f, err := os.Create(outFile)
+	if err != nil {
+		log.Fatalf("Failed to create file: %v", err)
+	}
+	defer f.Close()
+
+	// Copy data
+	written, err := io.Copy(f, result.Body)
+	if err != nil {
+		log.Fatalf("Failed to copy data: %v (wrote %d bytes)", err, written)
+	}
+
+	fmt.Printf("Successfully downloaded %d bytes\n", written)
+
+	// Rename
+	if err := os.Rename(outFile, "/tmp/test_grib"); err != nil {
+		log.Fatalf("Failed to rename: %v", err)
+	}
+
+	fmt.Println("Download complete!")
+}