Files
clan-core/pkgs/clan-cli/clan_cli/qemu/qga.py
2024-10-08 17:51:55 +00:00

83 lines
2.8 KiB
Python

import base64
import time
import types
from dataclasses import dataclass
from clan_cli.errors import ClanError
from clan_cli.qemu.qmp import QEMUMonitorProtocol
@dataclass
class VmCommandResult:
returncode: int
stdout: str | None
stderr: str | None
# qga is almost like qmp, but not quite, because:
# - server doesn't send initial message
# - no need to initialize by asking for capabilities
# - results need to be base64 decoded
class QgaSession:
def __init__(self, address: str) -> None:
self.client = QEMUMonitorProtocol(address)
self.client.connect(negotiate=False)
def __enter__(self) -> "QgaSession":
# Implement context manager enter function.
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: types.TracebackType | None,
) -> None:
# Implement context manager exit function.
self.client.close()
def run_nonblocking(self, cmd: list[str]) -> int:
result_pid = self.client.cmd(
"guest-exec", {"path": cmd[0], "arg": cmd[1:], "capture-output": True}
)
if result_pid is None:
msg = "Could not get PID from QGA"
raise ClanError(msg)
try:
return result_pid["return"]["pid"]
except KeyError as e:
if "error" in result_pid:
msg = f"Could not run command: {result_pid['error']['desc']}"
raise ClanError(msg) from e
msg = f"PID could not be found: {result_pid}"
raise ClanError(msg) from e
# run, wait for result, return exitcode and output
def run(self, cmd: list[str], check: bool = True) -> VmCommandResult:
pid = self.run_nonblocking(cmd)
# loop until exited=true
while True:
result = self.client.cmd("guest-exec-status", {"pid": pid})
if result is None:
msg = "Could not get status from QGA"
raise ClanError(msg)
if "error" in result and result["error"]["desc"].startswith("PID"):
msg = "PID could not be found"
raise ClanError(msg)
if result["return"]["exited"]:
break
time.sleep(0.1)
exitcode = result["return"]["exitcode"]
err_data = result["return"].get("err-data")
stdout = None
stderr = None
if out_data := result["return"].get("out-data"):
stdout = base64.b64decode(out_data).decode("utf-8")
if err_data is not None:
stderr = base64.b64decode(err_data).decode("utf-8")
if check and exitcode != 0:
msg = f"Command on guest failed\nCommand: {cmd}\nExitcode {exitcode}\nStdout: {stdout}\nStderr: {stderr}"
raise ClanError(msg)
return VmCommandResult(exitcode, stdout, stderr)