feat(prune): add prune files feature

This feature allows you to specify the n latest backups to keep in the
bucket.

helpers/helpers.go

@@ -0,0 +1,49 @@
+package helpers
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/minio/minio-go/v7"
+	"github.com/minio/minio-go/v7/pkg/credentials"
+	"os"
+)
+
+func GetCredentials() (string, string, error) {
+	// get credentials from env vars
+	keyName := os.Getenv("KEY_ID")
+	if keyName == "" {
+		return "", "", errors.New("missing or empty KEY_ID")
+	}
+	applicationKey := os.Getenv("APPLICATION_KEY")
+	if applicationKey == "" {
+		return "", "", errors.New("missing or empty APPLICATION_KEY")
+	}
+	return keyName, applicationKey, nil
+}
+
+func CreateClient(accessKeyID, secretAccessKey, endpoint string) (*minio.Client, error) {
+	// Initialize minio client object.
+	minioClient, err := minio.New(endpoint, &minio.Options{
+		Creds:  credentials.NewStaticV4(accessKeyID, secretAccessKey, ""),
+		Secure: true,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return minioClient, nil
+}
+
+func VerifyBucket(client *minio.Client, ctx context.Context, bucketName string) error {
+	exists, err := client.BucketExists(ctx, bucketName)
+	if err != nil {
+		return err
+	}
+
+	if !exists {
+		return errors.New(fmt.Sprintf("bucket %s does not exist\n", bucketName))
+	}
+
+	return nil
+}