如何使用 Go语言操作亚马逊 S3 对象云存储

以下是使用 Go 语言操作亚马逊 S3 对象云存储的详细步骤和示例代码：

解决思路：

1. 安装必要的 Go 语言包，这里我们将使用 aws-sdk-go 包来与 Amazon S3 进行交互。
2. 配置 AWS 凭证，包括访问密钥和秘密访问密钥，以及 AWS 区域。
3. 使用 aws-sdk-go 创建 S3 客户端。
4. 通过 S3 客户端执行各种操作，如上传文件、下载文件、列出存储桶中的对象等。

示例代码：

package s3Uploaderimport ("bytes""errors""fmt""github.com/aws/aws-sdk-go/aws""github.com/aws/aws-sdk-go/aws/credentials""github.com/aws/aws-sdk-go/aws/session""github.com/aws/aws-sdk-go/service/s3/s3manager""github.com/chai2010/webp" // WebP 库"github.com/nfnt/resize""html""image""image/jpeg""image/png""net/http""os""strings""upos/src/config"
)type S3Uploader struct {Name        stringScale       config.ScaleCfg         config.Sharktechuploader    *s3manager.UploaderContentType string
}var (ErrorUnsupportedImageFormat = errors.New("不支持的图片格式")
)func NewS3Uploader(cfg config.Sharktech) (*S3Uploader, error) {sess, err := session.NewSession(&aws.Config{Region:   aws.String(cfg.S3.Region),Endpoint: aws.String(cfg.S3.Endpoint),/*Set this to `true` to force the request to use path-style addressing,i.e., `http://s3.amazonaws.com/BUCKET/KEY`. By default, the S3 clientwill use virtual hosted bucket addressing when possible(`http://BUCKET.s3.amazonaws.com/KEY`).*/S3ForcePathStyle: aws.Bool(true),Credentials:      credentials.NewStaticCredentials(cfg.S3.AccessId, cfg.S3.AccessKey, ""),})if err != nil {return nil, err}uploader := s3manager.NewUploader(sess)return &S3Uploader{Cfg:      cfg,Scale:    config.YC.Scale,uploader: uploader,}, nil
}func (u *S3Uploader) ConvertWebPToJPG(file *os.File) (image.Image, error) {// 解码 WebP 文件为 image.Imageimg, err := webp.Decode(file)if err != nil {return nil, fmt.Errorf("解码 WebP 文件失败: %w", err)}return img, nil
}func (u *S3Uploader) ScaleImage(img image.Image, maxWidth, maxHeight uint) image.Image {// 获取原始图片的宽度和高度originalWidth := img.Bounds().Dx()originalHeight := img.Bounds().Dy()// 计算缩放比例ratio := float64(originalWidth) / float64(originalHeight)var newWidth, newHeight uintif ratio > 1 { // 图片宽 > 高newWidth = maxWidthnewHeight = uint(float64(maxWidth) / ratio)} else { // 图片高 >= 宽newHeight = maxHeightnewWidth = uint(float64(maxHeight) * ratio)}return resize.Resize(newWidth, newHeight, img, resize.Lanczos3)
}// 根据图片格式生成 Content-Type
func (u *S3Uploader) getContentType(format string) string {switch strings.ToLower(format) {case ".jpg", ".jpeg":return "image/jpeg"case ".png":return "image/png"case ".webp":return "image/webp"default:return "application/octet-stream" // 默认值}
}// 根据文件扩展名选择编码格式
func (u *S3Uploader) encodeImage(buf *bytes.Buffer, img image.Image, format string) error {switch strings.ToLower(format) {case ".jpg", ".jpeg":return jpeg.Encode(buf, img, nil)case ".png":return png.Encode(buf, img)case ".webp":return webp.Encode(buf, img, &webp.Options{Lossless: true})default:return ErrorUnsupportedImageFormat}
}// DetectFormatAndDecode 根据文件头判断图片格式并解码
func (u *S3Uploader) DetectFormatAndDecode(filePath string) (image.Image, string, error) {// 打开文件file, err := os.Open(filePath)if err != nil {return nil, "", err}defer file.Close()// 读取文件头前 12 个字节header := make([]byte, 12)_, err = file.Read(header)if err != nil {return nil, "", err}// 重置文件读取位置_, err = file.Seek(0, 0)if err != nil {return nil, "", err}// 根据文件头判断格式var img image.Imagevar ext stringswitch {case bytes.HasPrefix(header, []byte("\xFF\xD8\xFF")):// JPEG 文件头img, err = jpeg.Decode(file)ext = ".jpg"case bytes.HasPrefix(header, []byte("\x89PNG\r\n\x1a\n")):// PNG 文件头img, err = png.Decode(file)ext = ".png"case bytes.HasPrefix(header, []byte("RIFF")) && bytes.Contains(header[8:], []byte("WEBP")):// WebP 文件头img, err = webp.Decode(file)ext = ".webp"default:err = errors.New("unsupported image format")}return img, ext, err
}func (u *S3Uploader) Resize(filePath string) (buf bytes.Buffer, err error) {newImg, ext, err := u.DetectFormatAndDecode(filePath)if err != nil {return bytes.Buffer{}, err}u.ContentType = u.getContentType(ext)// 将缩放后的图片编码为 JPEG 格式err = u.encodeImage(&buf, newImg, ext)if err != nil {return}return buf, nil
}func (u *S3Uploader) Upload(filePath string, key string) error {buf, err := u.Resize(filePath)if err != nil {return err}_, err = u.uploader.Upload(&s3manager.UploadInput{ACL:    aws.String("public-read"), // 设置为 public-readBucket: aws.String(u.Cfg.S3.Bucket),Key:    aws.String(key),// TODO:: 不传Content-Type的好处是WP站点不好外链// ContentType: aws.String(u.ContentType),Body: bytes.NewReader(buf.Bytes()),})if err != nil {return err}return nil
}func (u *S3Uploader) DownloadAndUpload(imageUrl string, key string) error {buf, err := u.DownloadAndResizeImage(imageUrl)if err != nil {return err}_, err = u.uploader.Upload(&s3manager.UploadInput{ACL:    aws.String("public-read"), // 设置为 public-readBucket: aws.String(u.Cfg.S3.Bucket),Key:    aws.String(key),// TODO:: 不传Content-Type的好处是WP站点不好外链// ContentType: aws.String(u.ContentType),Body: bytes.NewReader(buf.Bytes()),})if err != nil {return err}return nil
}func (u *S3Uploader) DownloadAndResizeImage(imgURL string) (buf bytes.Buffer, err error) {imgURL = html.UnescapeString(imgURL)// 创建请求req, err := http.NewRequest("GET", imgURL, nil)if err != nil {return}// 设置 Referer 或 User-Agent，模拟合法请求req.Header.Set("Referer", "https://www.google.com")req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36")// 发起请求client := &http.Client{}resp, err := client.Do(req)if err != nil {return}defer resp.Body.Close()// 检查响应的Content-TypecontentType := resp.Header.Get("Content-Type")// log.Println("Content-Type:", contentType)if !strings.HasPrefix(contentType, "image/") {err = fmt.Errorf("invalid content type: %s", contentType)return}// 读取图片img, _, err := image.Decode(resp.Body)if err != nil {return}newImg := u.ScaleImage(img, u.Scale.Width, u.Scale.Height)// 将缩放后的图片编码为 JPG 格式err = u.encodeImage(&buf, newImg, ".jpg")if err != nil {return}return buf, nil
}