change type of userDataFlag

Author: GokceGK

docs/stackit_beta_server_create.md

@@ -38,7 +38,7 @@ stackit beta server create [flags]
   $ stackit beta server create --machine-type t1.1 --name server1 --boot-volume-source-id xxx --boot-volume-source-type image --boot-volume-size 64 --volumes yyy
 
   Create a server with user data (cloud-init)
-  $ stackit beta server create --machine-type t1.1 --name server1 --boot-volume-source-id xxx --boot-volume-source-type image --boot-volume-size 64 --user-data file("${path.module}/cloud-init.yaml")
+  $ stackit beta server create --machine-type t1.1 --name server1 --boot-volume-source-id xxx --boot-volume-source-type image --boot-volume-size 64 --user-data @path/to/file.yaml")
 ```
 
 ### Options

internal/cmd/beta/server/create/create.go

@@ -211,7 +211,7 @@ func configureFlags(cmd *cobra.Command) {
 	cmd.Flags().StringSlice(networkInterfaceIdsFlag, []string{}, "List of network interface IDs for the initial networking setup for the server creation")
 	cmd.Flags().StringSlice(securityGroupsFlag, []string{}, "The initial security groups for the server creation")
 	cmd.Flags().StringSlice(serviceAccountEmailsFlag, []string{}, "List of the service account mails")
-	cmd.Flags().String(userDataFlag, "", "User data that is passed via cloud-init to the server")
+	cmd.Flags().Var(flags.ReadFromFileFlag(), userDataFlag, "User data that is passed via cloud-init to the server")
 	cmd.Flags().StringSlice(volumesFlag, []string{}, "The list of volumes attached to the server")
 
 	err := flags.MarkFlagsRequired(cmd, nameFlag, machineTypeFlag)