import json
import logging
import shlex
from dataclasses import dataclass, field
from pathlib import Path
from tempfile import NamedTemporaryFile
from typing import TYPE_CHECKING, Dict, List, Tuple
from core.emulator.distributed import DistributedServer
from core.errors import CoreCommandError, CoreError
from core.executables import BASH
from core.nodes.base import CoreNode, CoreNodeOptions
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
from core.emulator.session import Session
DOCKER: str = "docker"
@dataclass
class DockerOptions(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
"""
@dataclass
class DockerVolume:
src: str
"""volume mount name"""
dst: str
"""volume mount destination directory"""
unique: bool = True
"""True to create a node unique prefixed name for this volume"""
delete: bool = True
"""True to delete the volume during shutdown"""
path: str = None
"""path to the volume on the host"""
class DockerNode(CoreNode):
"""
Provides logic for creating a Docker based node.
"""
def __init__(
self,
session: "Session",
_id: int = None,
name: str = None,
server: DistributedServer = None,
options: DockerOptions = None,
) -> None:
"""
Create a DockerNode instance.
:param session: core session instance
:param _id: node id
:param name: node name
:param server: remote server node
will run on, default is None for localhost
:param options: options for creating node
"""
options = options or DockerOptions()
super().__init__(session, _id, name, server, options)
self.image: str = options.image
self.binds: List[Tuple[str, str]] = options.binds
self.volumes: Dict[str, DockerVolume] = {}
for src, dst, unique, delete in options.volumes:
src_name = self._unique_name(src) if unique else src
self.volumes[src] = DockerVolume(src_name, dst, unique, delete)
@classmethod
def create_options(cls) -> DockerOptions:
"""
Return default creation options, which can be used during node creation.
:return: docker options
"""
return DockerOptions()
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 _unique_name(self, name: str) -> str:
"""
Creates a session/node unique prefixed name for the provided input.
:param name: name to make unique
:return: unique session/node prefixed name
"""
return f"{self.session.id}.{self.id}.{name}"
def alive(self) -> bool:
"""
Check if the node is alive.
:return: True if node is alive, False otherwise
"""
try:
running = self.host_cmd(
f"{DOCKER} inspect -f '{{{{.State.Running}}}}' {self.name}"
)
return json.loads(running)
except CoreCommandError:
return False
def startup(self) -> None:
"""
Create a docker container instance for the specified image.
:return: nothing
"""
with self.lock:
if self.up:
raise CoreError(f"starting node({self.name}) that is already up")
self.makenodedir()
binds = ""
for src, dst in self.binds:
binds += f"--mount type=bind,source={src},target={dst} "
volumes = ""
for volume in self.volumes.values():
volumes += (
f"--mount type=volume," f"source={volume.src},target={volume.dst} "
)
hostname = self.name.replace("_", "-")
self.host_cmd(
f"{DOCKER} run -td --init --net=none --hostname {hostname} "
f"--name {self.name} --sysctl net.ipv6.conf.all.disable_ipv6=0 "
f"{binds} {volumes} "
f"--privileged {self.image} tail -f /dev/null"
)
self.pid = self.host_cmd(
f"{DOCKER} inspect -f '{{{{.State.Pid}}}}' {self.name}"
)
for src, dst in self.binds:
link_path = self.host_path(Path(dst), True)
self.host_cmd(f"ln -s {src} {link_path}")
for volume in self.volumes.values():
volume.path = self.host_cmd(
f"{DOCKER} volume inspect -f '{{{{.Mountpoint}}}}' {volume.src}"
)
link_path = self.host_path(Path(volume.dst), True)
self.host_cmd(f"ln -s {volume.path} {link_path}")
logger.debug("node(%s) pid: %s", self.name, self.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"{DOCKER} rm -f {self.name}")
for volume in self.volumes.values():
if volume.delete:
self.host_cmd(f"{DOCKER} volume rm {volume.src}")
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
"""
terminal = f"{DOCKER} exec -it {self.name} {sh}"
if self.server is None:
return terminal
else:
return f"ssh -X -f {self.server.host} xterm -e {terminal}"
def create_dir(self, dir_path: Path) -> None:
"""
Create a private directory.
:param dir_path: path to create
:return: nothing
"""
logger.debug("creating node dir: %s", dir_path)
self.cmd(f"mkdir -p {dir_path}")
def mount(self, src_path: str, target_path: str) -> 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)
self.host_cmd(f"{DOCKER} cp {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()
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)
self.host_cmd(f"{DOCKER} cp {src_path} {self.name}:{dst_path}")
if mode is not None:
self.cmd(f"chmod {mode:o} {dst_path}")