code: def report_message(report):
      
      body = 'Error: return code != 0\n\n'
      body += 'Archive: {}\n\n'.format(report['archive'])
      body += 'Docker image: {}\n\n'.format(report['image'])
      body += 'Docker container: {}\n\n'.format(report['container_id'])
      return body
docs: Report message.