feat: add --location flag to specify datacenter region

Allow users to specify which Hetzner datacenter location to use for
the temporary server during image upload. Defaults to fsn1 for
backward compatibility.

Available locations: fsn1, nbg1, hel1, ash, hil, sin

hcloudimages/client.go

@@ -94,6 +94,10 @@ type UploadOptions struct {
 	// We also always add a label `apricote.de/created-by=hcloud-image-upload` ([CreatedByLabel], [CreatedByValue]).
 	Labels map[string]string
 
+	// Location is the datacenter location for the temporary server.
+	// Defaults to fsn1 if not specified.
+	Location *hcloud.Location
+
 	// DebugSkipResourceCleanup will skip the cleanup of the temporary SSH Key and Server.
 	DebugSkipResourceCleanup bool
 }
@@ -214,9 +218,14 @@ func (s *Client) Upload(ctx context.Context, options UploadOptions) (*hcloud.Ima
 		}
 	}
 
+	location := defaultLocation
+	if options.Location != nil {
+		location = options.Location
+	}
+
 	logger.DebugContext(ctx, "creating server with config",
 		"image", defaultImage.Name,
-		"location", defaultLocation.Name,
+		"location", location.Name,
 		"serverType", serverType.Name,
 	)
 	serverCreateResult, _, err := s.c.Server.Create(ctx, hcloud.ServerCreateOpts{
@@ -230,7 +239,7 @@ func (s *Client) Upload(ctx context.Context, options UploadOptions) (*hcloud.Ima
 		StartAfterCreate: hcloud.Ptr(false),
 		// Image will never be booted, we only boot into rescue system
 		Image:    defaultImage,
-		Location: defaultLocation,
+		Location: location,
 		Labels:   labels,
 	})
 	if err != nil {

hcloudimages/doc_test.go

@@ -24,6 +24,7 @@ func ExampleClient_Upload() {
 		ImageURL:         imageURL,
 		ImageCompression: hcloudimages.CompressionBZ2,
 		Architecture:     hcloud.ArchitectureX86,
+		Location:         &hcloud.Location{Name: "nbg1"}, // Optional: defaults to fsn1
 	})
 	if err != nil {
 		panic(err)