docker-s3-backup/internal/backup.go

package internal

import (
	"context"
	"fmt"
	"strings"

	"github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
)

var (
	MinioClient   *minio.Client
	backupBuckets = []string{}
	backupRoot    string
	s3Host        string
	s3Secure      bool
	s3Region      string
	s3User        string
	s3Pass        string
)

func init() {
	for _, bucket := range strings.Split(GetEnvWithDefault("BUCKET_NAMES", ""), ",") {
		backupBuckets = append(backupBuckets, strings.TrimSpace(bucket))
	}
	backupRoot = GetEnvWithDefault("BACKUP_ROOT", "/backup")
	s3Host = GetEnvWithDefault("S3_HOST", "localhost:9000")
	s3Secure = GetEnvWithDefault("S3_USE_SSL", "") == "true"
	s3Region = GetEnvWithDefault("S3_REGION", "us-east-1")
	s3User = GetEnvWithDefault("S3_ACCESS_KEY_ID", "")
	s3Pass = GetEnvWithDefault("S3_ACCESS_KEY_SECRET", "")
}

func Backup(ctx context.Context) error {
	logger.Info("Starting backup")
	var err error
	var getErrors = []string{}

	MinioClient, err = minio.New(s3Host, &minio.Options{
		Creds:  credentials.NewStaticV4(s3User, s3Pass, ""),
		Secure: s3Secure,
		Region: s3Region,
	})
	if err != nil {
		logger.Error("Error connecting to S3", "error", err)
		return err
	}
	logger.Debug("Connected to S3", "host", s3Host)

	for _, bucket := range backupBuckets {
		logger.Debug("Backing up bucket", "bucket", bucket)
		for object := range MinioClient.ListObjects(ctx, bucket, minio.ListObjectsOptions{Recursive: true}) {
			getError := MinioClient.FGetObject(ctx, bucket, object.Key, fmt.Sprintf("%s/%s/%s", backupRoot, bucket, object.Key), minio.GetObjectOptions{})
			if getError != nil {
				logger.Error("Error getting object", "bucket", bucket, "error", getError)
				getErrors = append(getErrors, getError.Error())
			}
		}
	}

	if len(getErrors) > 0 {
		err = fmt.Errorf("%d errors retrieving objects: %s", len(getErrors), strings.Join(getErrors, ", "))
	}

	return err
}