python - Catching exceptions on fabric -

i trying create script using fabric api (not fab files) , can't exceptions work. idea is, once host has failed, perhaps run rollback() function , write log file failed host. thing system exits. code:

class fabricexception(exception):     pass  class main(object):    def __init__(self):     env.password = 'password'     env.user = 'whatever'     command = 'sudo ls -la'     failed = []     env.warn_only = true     env.abort_exeption = fabricexception      def runcommand(command):         try:             result = run(command)         except fabricexeption:             print env.host + "failed"             failed.append = env.host      execute(runcommand, command=command, hosts=hosts)     disconnect_all()  if __name__ =="__main__":     main = main() 

if you're doing logging failure, why not use context manager, , have block of code warn. using either/both of these settings: env.warn_only , env.skip_bad_hosts.

refs:

• http://docs.fabfile.org/en/1.10/usage/execution.html#failure-handling
• http://docs.fabfile.org/en/1.10/usage/env.html#skip-bad-hosts
• http://docs.fabfile.org/en/1.10/usage/env.html#warn-only