core-extra/daemon/core/nodes/client.py
2019-10-11 13:36:00 -07:00

129 lines
3.3 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.
"""
import os
from core import constants, utils
class VnodeClient(object):
"""
Provides client functionality for interacting with a virtual node.
"""
def __init__(self, name, ctrlchnlname):
"""
Create a VnodeClient instance.
:param str name: name for client
:param str ctrlchnlname: control channel name
"""
self.name = name
self.ctrlchnlname = ctrlchnlname
def _verify_connection(self):
"""
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):
"""
Check if node is connected or not.
:return: True if connected, False otherwise
:rtype: bool
"""
return True
def close(self):
"""
Close the client connection.
:return: nothing
"""
pass
def _cmd_args(self):
return [constants.VCMD_BIN, "-c", self.ctrlchnlname, "--"]
def check_cmd(self, args, wait=True):
"""
Run command and return exit status and combined stdout and stderr.
:param list[str]|str args: command to run
:param bool wait: True to wait for command status, False otherwise
:return: combined stdout and stderr
:rtype: str
:raises core.CoreCommandError: when there is a non-zero exit status
"""
self._verify_connection()
args = utils.split_args(args)
args = self._cmd_args() + args
return utils.check_cmd(args, wait=wait)
def icmd(self, args):
"""
Execute an icmd against a node.
:param list[str]|str args: command arguments
:return: command result
:rtype: int
"""
args = utils.split_args(args)
return os.spawnlp(
os.P_WAIT,
constants.VCMD_BIN,
constants.VCMD_BIN,
"-c",
self.ctrlchnlname,
"--",
*args
)
def term(self, sh="/bin/sh"):
"""
Open a terminal on a node.
:param str sh: shell to open terminal with
:return: terminal command result
:rtype: int
"""
args = (
"xterm",
"-ut",
"-title",
self.name,
"-e",
constants.VCMD_BIN,
"-c",
self.ctrlchnlname,
"--",
sh,
)
if "SUDO_USER" in os.environ:
args = (
"su",
"-s",
"/bin/sh",
"-c",
"exec " + " ".join(map(lambda x: "'%s'" % x, args)),
os.environ["SUDO_USER"],
)
return os.spawnvp(os.P_NOWAIT, args[0], args)
def termcmdstring(self, sh="/bin/sh"):
"""
Create a terminal command string.
:param str sh: shell to execute command in
:return: str
"""
return "%s -c %s -- %s" % (constants.VCMD_BIN, self.ctrlchnlname, sh)