195 lines
7.6 KiB
Python
195 lines
7.6 KiB
Python
"""SSH client helpers for remote filesystem and media inspection.
|
|
|
|
All command execution goes through ``/bin/sh -c`` and all paths inserted into
|
|
commands are shell-quoted by callers. This is important for two reasons:
|
|
|
|
1. The remote login shell may be fish/csh/etc.; internal commands are POSIX sh.
|
|
2. Media paths frequently contain spaces and punctuation.
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
import json
|
|
import logging
|
|
import posixpath
|
|
import shlex
|
|
from dataclasses import dataclass
|
|
from io import StringIO
|
|
from pathlib import Path
|
|
from typing import Any
|
|
|
|
import paramiko
|
|
|
|
from media_library_viewer_api.services.known_hosts import ensure_known_host
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
@dataclass
|
|
class CommandResult:
|
|
"""Plain result object returned by remote command execution."""
|
|
|
|
command: str
|
|
exit_status: int
|
|
stdout: str
|
|
stderr: str
|
|
|
|
|
|
class RemoteSSHClient:
|
|
"""SSH helper for read-only inspection plus explicit job execution."""
|
|
|
|
def __init__(
|
|
self,
|
|
host: str,
|
|
username: str,
|
|
port: int = 22,
|
|
key_filename: str | None = None,
|
|
private_key: str | None = None,
|
|
private_key_passphrase: str | None = None,
|
|
password: str | None = None,
|
|
known_hosts_path: str | None = None,
|
|
timeout: int = 20,
|
|
):
|
|
if not host or not username:
|
|
raise ValueError("SSH host and username are required")
|
|
self.host = host
|
|
self.username = username
|
|
self.port = port
|
|
self.key_filename = key_filename or None
|
|
self.private_key = private_key or None
|
|
self.private_key_passphrase = private_key_passphrase or None
|
|
self.password = password or None
|
|
self.known_hosts_path = known_hosts_path or None
|
|
self.timeout = timeout
|
|
self._client: paramiko.SSHClient | None = None
|
|
|
|
def connect(self) -> paramiko.SSHClient:
|
|
"""Create or reuse the Paramiko connection.
|
|
|
|
Unknown host keys are recorded on first contact in the managed
|
|
known_hosts file when one is configured. After that, strict checking
|
|
remains in effect so host key changes are still rejected.
|
|
"""
|
|
if self._client:
|
|
return self._client
|
|
if self.known_hosts_path:
|
|
ensure_known_host(self.host, self.port, Path(self.known_hosts_path), strict=True)
|
|
client = paramiko.SSHClient()
|
|
client.load_system_host_keys()
|
|
if self.known_hosts_path and Path(self.known_hosts_path).is_file():
|
|
client.load_host_keys(self.known_hosts_path)
|
|
client.set_missing_host_key_policy(paramiko.RejectPolicy())
|
|
connect_kwargs: dict[str, Any] = {
|
|
"hostname": self.host,
|
|
"port": self.port,
|
|
"username": self.username,
|
|
"password": self.password,
|
|
"timeout": self.timeout,
|
|
}
|
|
if self.private_key:
|
|
connect_kwargs["pkey"] = self._load_private_key(self.private_key, self.private_key_passphrase)
|
|
else:
|
|
connect_kwargs["key_filename"] = self.key_filename
|
|
client.connect(**connect_kwargs)
|
|
self._client = client
|
|
return client
|
|
|
|
@staticmethod
|
|
def _load_private_key(private_key: str, passphrase: str | None = None) -> paramiko.PKey:
|
|
key_classes = [paramiko.Ed25519Key, paramiko.RSAKey, paramiko.ECDSAKey]
|
|
last_error: Exception | None = None
|
|
for key_class in key_classes:
|
|
try:
|
|
return key_class.from_private_key(StringIO(private_key), password=passphrase or None)
|
|
except Exception as exc: # pragma: no cover - try multiple algorithms
|
|
last_error = exc
|
|
raise RuntimeError("Unable to load SSH private key") from last_error
|
|
|
|
def close(self) -> None:
|
|
if self._client:
|
|
self._client.close()
|
|
self._client = None
|
|
|
|
def run(self, command: str, timeout: int | None = None) -> CommandResult:
|
|
"""Run a command through POSIX sh, independent of the user's login shell.
|
|
|
|
Paramiko asks the SSH server to execute a command using the account's
|
|
default shell. If that shell is fish/csh/etc., POSIX snippets containing
|
|
`if ...; then`, pipes, redirects, or heredocs can fail. All internal app
|
|
commands and job templates are written for POSIX shell, so explicitly
|
|
dispatch through `/bin/sh -c`.
|
|
"""
|
|
client = self.connect()
|
|
shell_command = f"/bin/sh -c {shlex.quote(command)}"
|
|
logger.debug("SSH run host=%s timeout=%s command=%s", self.host, timeout or self.timeout, command)
|
|
stdin, stdout, stderr = client.exec_command(shell_command, timeout=timeout or self.timeout)
|
|
exit_status = stdout.channel.recv_exit_status()
|
|
result = CommandResult(
|
|
command=command,
|
|
exit_status=exit_status,
|
|
stdout=stdout.read().decode(errors="replace"),
|
|
stderr=stderr.read().decode(errors="replace"),
|
|
)
|
|
if result.exit_status == 0:
|
|
logger.debug("SSH command ok host=%s exit_status=%s", self.host, result.exit_status)
|
|
else:
|
|
logger.warning(
|
|
"SSH command failed host=%s exit_status=%s stderr=%s",
|
|
self.host,
|
|
result.exit_status,
|
|
result.stderr.strip() or result.stdout.strip(),
|
|
)
|
|
return result
|
|
|
|
def list_dir(self, path: str) -> CommandResult:
|
|
"""List one remote directory as JSON.
|
|
|
|
The command first verifies that ``path`` is a directory. Without that
|
|
guard, running ``find`` on a file can look like an empty directory, which
|
|
was a source of file-browser confusion. Output is NUL-delimited before
|
|
Python serializes it, making spaces in filenames safe.
|
|
"""
|
|
quoted = shlex.quote(path)
|
|
not_dir_message = shlex.quote(f"Not a directory: {path}")
|
|
command = (
|
|
f"test -d {quoted} || "
|
|
f"{{ echo {not_dir_message} >&2; exit 20; }}; "
|
|
f"find {quoted} -maxdepth 1 -mindepth 1 -printf "
|
|
"'%y\\t%s\\t%T@\\t%f\\0' | python3 -c "
|
|
+ shlex.quote(
|
|
"import sys,json; data=sys.stdin.buffer.read().split(b'\\0'); "
|
|
"rows=[]\n"
|
|
"for row in data:\n"
|
|
" if not row: continue\n"
|
|
" t,s,m,n=row.decode('utf-8','replace').split('\\t',3)\n"
|
|
" rows.append({'type':t,'size':int(s),'mtime':float(m),'name':n})\n"
|
|
"print(json.dumps(rows))"
|
|
)
|
|
)
|
|
result = self.run(command)
|
|
logger.info("SSH list_dir path=%s exit_status=%s", path, result.exit_status)
|
|
return result
|
|
|
|
def stat_path(self, path: str) -> CommandResult:
|
|
"""Run stat for a remote file or directory path."""
|
|
quoted = shlex.quote(path)
|
|
result = self.run(f"stat --printf='%F\\n%s bytes\\n%y\\n%n\\n' {quoted}")
|
|
logger.info("SSH stat path=%s exit_status=%s", path, result.exit_status)
|
|
return result
|
|
|
|
def ffprobe_json(self, path: str) -> dict[str, Any]:
|
|
"""Run ffprobe and parse JSON output for a remote media file."""
|
|
quoted = shlex.quote(path)
|
|
result = self.run(
|
|
"ffprobe -v error -show_format -show_streams -print_format json " + quoted,
|
|
timeout=60,
|
|
)
|
|
logger.info("SSH ffprobe path=%s exit_status=%s", path, result.exit_status)
|
|
if result.exit_status != 0:
|
|
raise RuntimeError(result.stderr or result.stdout or "ffprobe failed")
|
|
return json.loads(result.stdout)
|
|
|
|
@staticmethod
|
|
def join(parent: str, child: str) -> str:
|
|
return posixpath.normpath(posixpath.join(parent, child))
|