go-storage/pkg/s3/s3.go

/*
MIT License

Copyright (c) 2023 Jonas Kaninda

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

package s3

import (
	"bytes"
	"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"
	"github.com/aws/aws-sdk-go/service/s3/s3manager"
	"github.com/jkaninda/go-storage/pkg"
	"net/http"
	"os"
	"path/filepath"
	"time"
)

type s3Storage struct {
	*pkg.Backend
	client *session.Session
	bucket string
}

// Config holds the AWS S3 config
type Config struct {
	Endpoint       string
	Bucket         string
	AccessKey      string
	SecretKey      string
	Region         string
	DisableSsl     bool
	ForcePathStyle bool
	LocalPath      string
	RemotePath     string
}

// CreateSession creates a new AWS session
func createSession(conf Config) (*session.Session, error) {
	s3Config := &aws.Config{
		Credentials:      credentials.NewStaticCredentials(conf.AccessKey, conf.SecretKey, ""),
		Endpoint:         aws.String(conf.Endpoint),
		Region:           aws.String(conf.Region),
		DisableSSL:       aws.Bool(conf.DisableSsl),
		S3ForcePathStyle: aws.Bool(conf.ForcePathStyle),
	}

	return session.NewSession(s3Config)
}

// NewStorage creates new Storage
func NewStorage(conf Config) (pkg.Storage, error) {
	sess, err := createSession(conf)
	if err != nil {
		return nil, err
	}
	return &s3Storage{
		client: sess,
		bucket: conf.Bucket,
		Backend: &pkg.Backend{
			RemotePath: conf.RemotePath,
			LocalPath:  conf.LocalPath,
		},
	}, nil
}

// Copy copies file to S3 storage
func (s s3Storage) Copy(fileName string) error {
	svc := s3.New(s.client)
	file, err := os.Open(filepath.Join(s.LocalPath, fileName))
	if err != nil {
		return err
	}
	defer func(file *os.File) {
		err := file.Close()
		if err != nil {
			return
		}
	}(file)

	fileInfo, err := file.Stat()
	if err != nil {
		return err
	}
	objectKey := filepath.Join(s.RemotePath, fileName)
	buffer := make([]byte, fileInfo.Size())
	_, err = file.Read(buffer)
	if err != nil {
		return err
	}
	fileBytes := bytes.NewReader(buffer)
	fileType := http.DetectContentType(buffer)

	_, err = svc.PutObject(&s3.PutObjectInput{
		Bucket:        aws.String(s.bucket),
		Key:           aws.String(objectKey),
		Body:          fileBytes,
		ContentLength: aws.Int64(fileInfo.Size()),
		ContentType:   aws.String(fileType),
	})
	if err != nil {
		return err
	}

	return nil
}

// CopyFrom copies a file from S3 to local storage
func (s s3Storage) CopyFrom(fileName string) error {
	file, err := os.Create(filepath.Join(s.LocalPath, fileName))
	if err != nil {
		return err
	}
	defer func(file *os.File) {
		err := file.Close()
		if err != nil {
			fmt.Printf("Error closing file: %v\n", err)
			return
		}
	}(file)

	objectKey := filepath.Join(s.RemotePath, fileName)

	downloader := s3manager.NewDownloader(s.client)
	_, err = downloader.Download(file,
		&s3.GetObjectInput{
			Bucket: aws.String(s.bucket),
			Key:    aws.String(objectKey),
		})
	if err != nil {
		return err
	}
	return nil
}

// Prune deletes old backup created more than specified days
func (s s3Storage) Prune(retentionDays int) error {
	svc := s3.New(s.client)

	// Get the current time
	now := time.Now()
	backupRetentionDays := now.AddDate(0, 0, -retentionDays)

	// List objects in the bucket
	listObjectsInput := &s3.ListObjectsV2Input{
		Bucket: aws.String(s.bucket),
		Prefix: aws.String(s.RemotePath),
	}
	err := svc.ListObjectsV2Pages(listObjectsInput, func(page *s3.ListObjectsV2Output, lastPage bool) bool {
		for _, object := range page.Contents {
			if object.LastModified.Before(backupRetentionDays) {
				// Object is older than retention days, delete it
				_, err := svc.DeleteObject(&s3.DeleteObjectInput{
					Bucket: aws.String(s.bucket),
					Key:    object.Key,
				})
				if err != nil {
					fmt.Printf("failed to delete object %s: %v\n", *object.Key, err)
				} else {
					fmt.Printf("Deleted object %s\n", *object.Key)
				}
			}
		}
		return !lastPage
	})
	if err != nil {
		return fmt.Errorf("failed to list objects: %v\n", err)
	}

	return nil

}

// Name returns the storage name
func (s s3Storage) Name() string {
	return "s3"
}