Improve process handling in _get_ssh_ambient_options

Thanks Mic92!

nixops/backends/__init__.py

@@ -469,22 +469,17 @@ def get_ssh_host_keys(self) -> Optional[str]:
  return None
 
  def _get_ssh_ambient_options(self) -> Dict[str, str]:
- proc = subprocess.Popen(
- ["ssh", "-G", self.get_ssh_name()], stdout=subprocess.PIPE
- )
- opts: Dict[str, str] = {}
- if proc.stdout is None: # mostly for mypy; Popen won't do this to us.
- return opts
- while True:
- line = proc.stdout.readline()
- if not line:
- break
+ with subprocess.Popen(
+ ["ssh", "-G", self.get_ssh_name()], stdout=subprocess.PIPE, text=True
+ ) as proc:
+ assert proc.stdout is not None
+ opts: Dict[str, str] = {}
+ for line in proc.stdout:
+ s = line.rstrip("\r\n").split(" ", 1)
+ if len(s) == 2:
+ opts[s[0].lower()] = s[1]
 
- s = line.decode("utf-8").rstrip("\r\n").split(" ", 1)
- if len(s) == 2:
- opts[s[0].lower()] = s[1]
-
- return opts
+ return opts
 
  def get_known_hosts_file(self, *args, **kwargs) -> Optional[str]:
  k = self.get_ssh_host_keys()