Add option to provide custom endpoint for S3, add option to specify S3 config profile (#243)

* Add option to provide custom endpoint for S3 for use with s3-compatible storages, add option to specify S3 config profile

* make fmt

app/vmbackup/README.md

@@ -132,6 +132,10 @@ Run `vmbackup -help` in order to see all the available options:
   -credsFilePath string
     	Path to file with GCS or S3 credentials. Credentials are loaded from default locations if not set.
     	See https://cloud.google.com/iam/docs/creating-managing-service-account-keys and https://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html
+  -configProfile string
+    	Profile name for S3 configs.  (default "default")
+  -customS3Endpoint string
+    	Custom S3 endpoint for use with S3-compatible storages (e.g. MinIO)
   -dst string
     	Where to put the backup on the remote storage. Example: gcs://bucket/path/to/backup/dir, s3://bucket/path/to/backup/dir or fs:///path/to/local/backup/dir
     	-dst can point to the previous backup. In this case incremental backup is performed, i.e. only changed data is uploaded

app/vmrestore/README.md

@@ -43,6 +43,10 @@ Run `vmrestore -help` in order to see all the available options:
   -credsFilePath string
     	Path to file with GCS or S3 credentials. Credentials are loaded from default locations if not set.
     	See https://cloud.google.com/iam/docs/creating-managing-service-account-keys and https://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html
+  -configProfile string
+    	Profile name for S3 configs.  (default "default")
+  -customS3Endpoint string
+    	Custom S3 endpoint for use with S3-compatible storages (e.g. MinIO)
   -loggerLevel string
     	Minimum level of errors to log. Possible values: INFO, ERROR, FATAL, PANIC (default "INFO")
   -maxBytesPerSecond int

lib/backup/actions/util.go

@@ -18,6 +18,8 @@ var (
 		"See https://cloud.google.com/iam/docs/creating-managing-service-account-keys and https://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html")
 	configFilePath = flag.String("configFilePath", "", "Path to file with S3 configs. Configs are loaded from default location if not set.\n"+
 		"See https://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html")
+	configProfile    = flag.String("configProfile", "default", "Profile name for S3 configs. ")
+	customS3Endpoint = flag.String("customS3Endpoint", "", "Custom S3 endpoint for use with S3-compatible storages (e.g. MinIO)")
 )
 
 func runParallel(concurrency int, parts []common.Part, f func(p common.Part) error, progress func(elapsed time.Duration)) error {
@@ -218,6 +220,8 @@ func NewRemoteFS(path string) (common.RemoteFS, error) {
 		fs := &s3remote.FS{
 			CredsFilePath:  *credsFilePath,
 			ConfigFilePath: *configFilePath,
+			CustomEndpoint: *customS3Endpoint,
+			ProfileName:    *configProfile,
 			Bucket:         bucket,
 			Dir:            dir,
 		}

lib/backup/s3remote/s3.go

@@ -30,8 +30,10 @@ type FS struct {
 	// Directory in the bucket to write to.
 	Dir string
 
-	s3       *s3.S3
-	uploader *s3manager.Uploader
+	s3             *s3.S3
+	uploader       *s3manager.Uploader
+	CustomEndpoint string
+	ProfileName    string
 }
 
 // Init initializes fs.
@@ -47,6 +49,7 @@ func (fs *FS) Init() error {
 	}
 	opts := session.Options{
 		SharedConfigState: session.SharedConfigEnable,
+		Profile:           fs.ProfileName,
 	}
 	if len(fs.CredsFilePath) > 0 {
 		opts.SharedConfigFiles = []string{
@@ -59,14 +62,25 @@ func (fs *FS) Init() error {
 		return fmt.Errorf("cannot create S3 session: %s", err)
 	}
 
-	// Determine bucket region.
-	ctx := context.Background()
-	region, err := s3manager.GetBucketRegion(ctx, sess, fs.Bucket, "")
-	if err != nil {
-		return fmt.Errorf("cannot determine region for bucket %q: %s", fs.Bucket, err)
+	if len(fs.CustomEndpoint) > 0 {
+
+		// Use provided custom endpoint for S3
+		logger.Infof("Using provided custom S3 endpoint: %q", fs.CustomEndpoint)
+		sess.Config.WithEndpoint(fs.CustomEndpoint)
+
+		// Disable prefixing endpoint with bucket name
+		sess.Config.WithS3ForcePathStyle(true)
+	} else {
+
+		// Determine bucket region.
+		ctx := context.Background()
+		region, err := s3manager.GetBucketRegion(ctx, sess, fs.Bucket, "")
+		if err != nil {
+			return fmt.Errorf("cannot determine region for bucket %q: %s", fs.Bucket, err)
+		}
+		sess.Config.WithRegion(region)
+		logger.Infof("bucket %q is stored at region %q; switching to this region", fs.Bucket, region)
 	}
-	sess.Config.WithRegion(region)
-	logger.Infof("bucket %q is stored at region %q; switching to this region", fs.Bucket, region)
 
 	fs.s3 = s3.New(sess)
 	fs.uploader = s3manager.NewUploader(sess, func(u *s3manager.Uploader) {