core-extra/daemon/core/nodes/client.py

67 lines
1.9 KiB
Python

"""
client.py: implementation of the VnodeClient class for issuing commands
over a control channel to the vnoded process running in a network namespace.
The control channel can be accessed via calls using the vcmd shell.
"""
from core import utils
from core.constants import VCMD_BIN
class VnodeClient:
"""
Provides client functionality for interacting with a virtual node.
"""
def __init__(self, name: str, ctrlchnlname: str) -> None:
"""
Create a VnodeClient instance.
:param name: name for client
:param ctrlchnlname: control channel name
"""
self.name: str = name
self.ctrlchnlname: str = ctrlchnlname
def _verify_connection(self) -> None:
"""
Checks that the vcmd client is properly connected.
:return: nothing
:raises IOError: when not connected
"""
if not self.connected():
raise IOError("vcmd not connected")
def connected(self) -> bool:
"""
Check if node is connected or not.
:return: True if connected, False otherwise
"""
return True
def close(self) -> None:
"""
Close the client connection.
:return: nothing
"""
pass
def create_cmd(self, args: str) -> str:
return f"{VCMD_BIN} -c {self.ctrlchnlname} -- {args}"
def check_cmd(self, args: str, wait: bool = True, shell: bool = False) -> str:
"""
Run command and return exit status and combined stdout and stderr.
:param args: command to run
:param wait: True to wait for command status, False otherwise
:param shell: True to use shell, False otherwise
:return: combined stdout and stderr
:raises core.CoreCommandError: when there is a non-zero exit status
"""
self._verify_connection()
args = self.create_cmd(args)
return utils.cmd(args, wait=wait, shell=shell)