import json import logging import shlex import time from dataclasses import dataclass, field from pathlib import Path from tempfile import NamedTemporaryFile from typing import TYPE_CHECKING, Dict, List, Tuple from core.emulator.data import InterfaceData, LinkOptions from core.emulator.distributed import DistributedServer from core.errors import CoreCommandError from core.executables import BASH from core.nodes.base import CoreNode, CoreNodeOptions from core.nodes.interface import CoreInterface logger = logging.getLogger(__name__) if TYPE_CHECKING: from core.emulator.session import Session @dataclass class LxcOptions(CoreNodeOptions): image: str = "ubuntu" """image used when creating container""" binds: List[Tuple[str, str]] = field(default_factory=list) """bind mount source and destinations to setup within container""" volumes: List[Tuple[str, str, bool, bool]] = field(default_factory=list) """ volume mount source, destination, unique, delete to setup within container unique is True for node unique volume naming delete is True for deleting volume mount during shutdown """ class LxcNode(CoreNode): def __init__( self, session: "Session", _id: int = None, name: str = None, server: DistributedServer = None, options: LxcOptions = None, ) -> None: """ Create a LxcNode instance. :param session: core session instance :param _id: object id :param name: object name :param server: remote server node will run on, default is None for localhost :param options: option to create node with """ options = options or LxcOptions() super().__init__(session, _id, name, server, options) self.image: str = options.image @classmethod def create_options(cls) -> LxcOptions: return LxcOptions() def _create_cmd(self, args: str, shell: bool = False) -> str: """ Create command used to run commands within the context of a node. :param args: command arguments :param shell: True to run shell like, False otherwise :return: node command """ if shell: args = f"{BASH} -c {shlex.quote(args)}" return f"nsenter -t {self.pid} -m -u -i -p -n {args}" def _get_info(self) -> Dict: args = f"lxc list {self.name} --format json" output = self.host_cmd(args) data = json.loads(output) if not data: raise CoreCommandError(1, args, f"LXC({self.name}) not present") return data[0] def alive(self) -> bool: """ Check if the node is alive. :return: True if node is alive, False otherwise """ try: data = self._get_info() return data["state"]["status"] == "Running" except CoreCommandError: return False def startup(self) -> None: """ Startup logic. :return: nothing """ with self.lock: if self.up: raise ValueError("starting a node that is already up") self.makenodedir() self.host_cmd(f"lxc launch {self.image} {self.name}") data = self._get_info() self.pid = data["state"]["pid"] self.up = True def shutdown(self) -> None: """ Shutdown logic. :return: nothing """ # nothing to do if node is not up if not self.up: return with self.lock: self.ifaces.clear() self.host_cmd(f"lxc delete --force {self.name}") self.up = False def termcmdstring(self, sh: str = "/bin/sh") -> str: """ Create a terminal command string. :param sh: shell to execute command in :return: str """ return f"lxc exec {self.name} -- {sh}" def create_dir(self, dir_path: Path) -> None: """ Create a private directory. :param dir_path: path to create :return: nothing """ logger.info("creating node dir: %s", dir_path) args = f"mkdir -p {dir_path}" self.cmd(args) def mount(self, src_path: Path, target_path: Path) -> None: """ Create and mount a directory. :param src_path: source directory to mount :param target_path: target directory to create :return: nothing :raises CoreCommandError: when a non-zero exit status occurs """ logger.debug("mounting source(%s) target(%s)", src_path, target_path) raise Exception("not supported") def create_file(self, file_path: Path, contents: str, mode: int = 0o644) -> None: """ Create a node file with a given mode. :param file_path: name of file to create :param contents: contents of file :param mode: mode for file :return: nothing """ logger.debug("node(%s) create file(%s) mode(%o)", self.name, file_path, mode) temp = NamedTemporaryFile(delete=False) temp.write(contents.encode("utf-8")) temp.close() temp_path = Path(temp.name) directory = file_path.parent if str(directory) != ".": self.cmd(f"mkdir -m {0o755:o} -p {directory}") if self.server is not None: self.server.remote_put(temp_path, temp_path) if not str(file_path).startswith("/"): file_path = Path("/root/") / file_path self.host_cmd(f"lxc file push {temp_path} {self.name}/{file_path}") self.cmd(f"chmod {mode:o} {file_path}") if self.server is not None: self.host_cmd(f"rm -f {temp_path}") temp_path.unlink() logger.debug("node(%s) added file: %s; mode: 0%o", self.name, file_path, mode) def copy_file(self, src_path: Path, dst_path: Path, mode: int = None) -> None: """ Copy a file to a node, following symlinks and preserving metadata. Change file mode if specified. :param dst_path: file name to copy file to :param src_path: file to copy :param mode: mode to copy to :return: nothing """ logger.info( "node file copy file(%s) source(%s) mode(%o)", dst_path, src_path, mode or 0 ) self.cmd(f"mkdir -p {dst_path.parent}") if self.server: temp = NamedTemporaryFile(delete=False) temp_path = Path(temp.name) src_path = temp_path self.server.remote_put(src_path, temp_path) if not str(dst_path).startswith("/"): dst_path = Path("/root/") / dst_path self.host_cmd(f"lxc file push {src_path} {self.name}/{dst_path}") if mode is not None: self.cmd(f"chmod {mode:o} {dst_path}") def create_iface( self, iface_data: InterfaceData = None, options: LinkOptions = None ) -> CoreInterface: iface = super().create_iface(iface_data, options) # adding small delay to allow time for adding addresses to work correctly time.sleep(0.5) return iface