---
name: s3_upload
kind: function
lang: go
domain: infra
version: "1.0.0"
purity: impure
signature: "func S3Upload(cfg S3Config, key string, data io.Reader, contentType string) error"
description: "STUB. Sube data a un bucket S3-compatible (AWS S3, MinIO, etc) bajo la key indicada con el Content-Type dado. La implementacion real requiere github.com/aws/aws-sdk-go-v2."
tags: [s3, upload, storage, cloud, stub, infra]
uses_functions: []
uses_types: [S3Config_go_infra]
returns: []
returns_optional: false
error_type: "error_go_core"
imports: [fmt, io, time]
params:
  - name: cfg
    desc: "S3Config con endpoint, bucket, credenciales y region"
  - name: key
    desc: "key del objeto en el bucket (ej: \"images/foto.png\")"
  - name: data
    desc: "reader con el contenido binario a subir"
  - name: contentType
    desc: "MIME type del objeto (ej: \"image/png\")"
output: "nil si la subida fue exitosa, error si fallo. STUB actual retorna siempre error \"not implemented\""
tested: false
tests: []
test_file_path: ""
file_path: "functions/infra/s3_upload.go"
---

## Estado

**Stub**. Para activar la implementacion real:

1. Anadir dependencias:
   ```bash
   go get github.com/aws/aws-sdk-go-v2/aws
   go get github.com/aws/aws-sdk-go-v2/config
   go get github.com/aws/aws-sdk-go-v2/credentials
   go get github.com/aws/aws-sdk-go-v2/service/s3
   ```
2. Reemplazar el cuerpo del stub por:
   ```go
   import (
       "context"
       "github.com/aws/aws-sdk-go-v2/aws"
       awscfg "github.com/aws/aws-sdk-go-v2/config"
       "github.com/aws/aws-sdk-go-v2/credentials"
       "github.com/aws/aws-sdk-go-v2/service/s3"
   )

   func S3Upload(cfg S3Config, key string, data io.Reader, contentType string) error {
       ctx := context.Background()
       awsCfg, err := awscfg.LoadDefaultConfig(ctx,
           awscfg.WithRegion(cfg.Region),
           awscfg.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(
               cfg.AccessKey, cfg.SecretKey, "")),
       )
       if err != nil {
           return fmt.Errorf("s3_upload: aws config: %w", err)
       }
       client := s3.NewFromConfig(awsCfg, func(o *s3.Options) {
           o.UsePathStyle = true
           if cfg.Endpoint != "" {
               scheme := "http"
               if cfg.UseSSL {
                   scheme = "https"
               }
               o.BaseEndpoint = aws.String(fmt.Sprintf("%s://%s", scheme, cfg.Endpoint))
           }
       })
       _, err = client.PutObject(ctx, &s3.PutObjectInput{
           Bucket:      aws.String(cfg.Bucket),
           Key:         aws.String(key),
           Body:        data,
           ContentType: aws.String(contentType),
       })
       return err
   }
   ```

## Ejemplo (con implementacion real)

```go
cfg := S3Config{
    Endpoint:  "s3.amazonaws.com",
    Bucket:    "mi-bucket",
    AccessKey: os.Getenv("S3_ACCESS_KEY"),
    SecretKey: os.Getenv("S3_SECRET_KEY"),
    Region:    "us-east-1",
    UseSSL:    true,
}
f, _ := os.Open("./uploads/photo.png")
defer f.Close()
err := S3Upload(cfg, "images/photo.png", f, "image/png")
```

## Notas

Compatible con AWS S3, MinIO, Wasabi y otros S3-compatible. El campo `UsePathStyle = true` es necesario para MinIO y para algunos endpoints custom; AWS S3 nativo soporta tanto path-style como virtual-hosted-style.