"""SSH remote execution environment with ControlMaster connection persistence.""" import logging import shlex import shutil import subprocess import tempfile from pathlib import Path from tools.environments.base import BaseEnvironment, _popen_bash logger = logging.getLogger(__name__) def _ensure_ssh_available() -> None: """Fail fast with a clear error when the SSH client is unavailable.""" if not shutil.which("ssh"): raise RuntimeError( "SSH is not installed or not in PATH. Install OpenSSH client: apt install openssh-client" ) class SSHEnvironment(BaseEnvironment): """Run commands on a remote machine over SSH. Spawn-per-call: every execute() spawns a fresh ``ssh ... bash -c`` process. Session snapshot preserves env vars across calls. CWD persists via in-band stdout markers. Uses SSH ControlMaster for connection reuse. """ def __init__(self, host: str, user: str, cwd: str = "~", timeout: int = 60, port: int = 22, key_path: str = ""): super().__init__(cwd=cwd, timeout=timeout) self.host = host self.user = user self.port = port self.key_path = key_path self.control_dir = Path(tempfile.gettempdir()) / "hermes-ssh" self.control_dir.mkdir(parents=True, exist_ok=True) self.control_socket = self.control_dir / f"{user}@{host}:{port}.sock" _ensure_ssh_available() self._establish_connection() self._remote_home = self._detect_remote_home() self._last_sync_time: float = 0 # guarantees first _before_execute syncs self._sync_files() self.init_session() def _build_ssh_command(self, extra_args: list | None = None) -> list: cmd = ["ssh"] cmd.extend(["-o", f"ControlPath={self.control_socket}"]) cmd.extend(["-o", "ControlMaster=auto"]) cmd.extend(["-o", "ControlPersist=300"]) cmd.extend(["-o", "BatchMode=yes"]) cmd.extend(["-o", "StrictHostKeyChecking=accept-new"]) cmd.extend(["-o", "ConnectTimeout=10"]) if self.port != 22: cmd.extend(["-p", str(self.port)]) if self.key_path: cmd.extend(["-i", self.key_path]) if extra_args: cmd.extend(extra_args) cmd.append(f"{self.user}@{self.host}") return cmd def _establish_connection(self): cmd = self._build_ssh_command() cmd.append("echo 'SSH connection established'") try: result = subprocess.run(cmd, capture_output=True, text=True, timeout=15) if result.returncode != 0: error_msg = result.stderr.strip() or result.stdout.strip() raise RuntimeError(f"SSH connection failed: {error_msg}") except subprocess.TimeoutExpired: raise RuntimeError(f"SSH connection to {self.user}@{self.host} timed out") def _detect_remote_home(self) -> str: """Detect the remote user's home directory.""" try: cmd = self._build_ssh_command() cmd.append("echo $HOME") result = subprocess.run(cmd, capture_output=True, text=True, timeout=10) home = result.stdout.strip() if home and result.returncode == 0: logger.debug("SSH: remote home = %s", home) return home except Exception: pass if self.user == "root": return "/root" return f"/home/{self.user}" def _sync_files(self) -> None: """Rsync skills directory and credential files to the remote host.""" try: container_base = f"{self._remote_home}/.hermes" from tools.credential_files import get_credential_file_mounts, get_skills_directory_mount rsync_base = ["rsync", "-az", "--timeout=30", "--safe-links"] ssh_opts = f"ssh -o ControlPath={self.control_socket} -o ControlMaster=auto" if self.port != 22: ssh_opts += f" -p {self.port}" if self.key_path: ssh_opts += f" -i {self.key_path}" rsync_base.extend(["-e", ssh_opts]) dest_prefix = f"{self.user}@{self.host}" for mount_entry in get_credential_file_mounts(): remote_path = mount_entry["container_path"].replace("/root/.hermes", container_base, 1) parent_dir = str(Path(remote_path).parent) mkdir_cmd = self._build_ssh_command() mkdir_cmd.append(f"mkdir -p {parent_dir}") subprocess.run(mkdir_cmd, capture_output=True, text=True, timeout=10) cmd = rsync_base + [mount_entry["host_path"], f"{dest_prefix}:{remote_path}"] result = subprocess.run(cmd, capture_output=True, text=True, timeout=30) if result.returncode == 0: logger.info("SSH: synced credential %s -> %s", mount_entry["host_path"], remote_path) else: logger.debug("SSH: rsync credential failed: %s", result.stderr.strip()) for skills_mount in get_skills_directory_mount(container_base=container_base): remote_path = skills_mount["container_path"] mkdir_cmd = self._build_ssh_command() mkdir_cmd.append(f"mkdir -p {remote_path}") subprocess.run(mkdir_cmd, capture_output=True, text=True, timeout=10) cmd = rsync_base + [ skills_mount["host_path"].rstrip("/") + "/", f"{dest_prefix}:{remote_path}/", ] result = subprocess.run(cmd, capture_output=True, text=True, timeout=60) if result.returncode == 0: logger.info("SSH: synced skills dir %s -> %s", skills_mount["host_path"], remote_path) else: logger.debug("SSH: rsync skills dir failed: %s", result.stderr.strip()) except Exception as e: logger.debug("SSH: could not sync skills/credentials: %s", e) def _run_bash(self, cmd_string: str, *, login: bool = False, timeout: int = 120, stdin_data: str | None = None) -> subprocess.Popen: """Spawn an SSH process that runs bash on the remote host.""" cmd = self._build_ssh_command() if login: cmd.extend(["bash", "-l", "-c", shlex.quote(cmd_string)]) else: cmd.extend(["bash", "-c", shlex.quote(cmd_string)]) return _popen_bash(cmd, stdin_data) def cleanup(self): if self.control_socket.exists(): try: cmd = ["ssh", "-o", f"ControlPath={self.control_socket}", "-O", "exit", f"{self.user}@{self.host}"] subprocess.run(cmd, capture_output=True, timeout=5) except (OSError, subprocess.SubprocessError): pass try: self.control_socket.unlink() except OSError: pass