code: def get_default_image_build_conf(self):
          
          target = self.koji_target
  
          vcs_info = self.workflow.source.get_vcs_info()
          ksurl = '{}#{}'.format(vcs_info.vcs_url, vcs_info.vcs_ref)
  
          base_urls = []
          for repo in self.repos:
              for url in self.extract_base_url(repo):
                  # Imagefactory only supports $arch variable.
                  url = url.replace('$basearch', '$arch')
                  base_urls.append(url)
  
          install_tree = base_urls[0] if base_urls else ''
  
          repo = ','.join(base_urls)
  
          kwargs = {
              'target': target,
              'ksurl': ksurl,
              'install_tree': install_tree,
              'repo': repo,
          }
          config_fp = StringIO(self.DEFAULT_IMAGE_BUILD_CONF.format(**kwargs))
  
          config = ConfigParser()
          config.readfp(config_fp)
  
          self.update_config_from_dockerfile(config)
  
          return config
docs: Create a default image build config
  
          :rtype: ConfigParser
          :return: Initialized config with defaults