DockerNode copyFromNode() depends on file permissions

[kwart]

Internal ID: 38

DockerNode.copyFromNode() uses Docker copy API internally, so it shouldn't care about file permissions. Nevertheless, the checks in the implemented method executes file-type tests under the configured user. When the container's user doesn't have permissions to see the file, the operation results in FileNotFoundException.

Let's decide

if (it's a bug) {
  fixIt();
} else {
  documentIt();
}