import paramiko as pikuniku # :P from paramiko.client import SSHClient from io import BytesIO from pathlib import Path from typing import Union, Optional import errno import stat class Connection: """Class representing an SSH/SFTP connection to a Vessel """ def __init__(self, vessel): """Initialize a new Connection to a Vessel Args: vessel (classes.vessel.Vessel): Vessel object to open connection to """ self._vessel = vessel self._client = SSHClient() self._client.load_system_host_keys() self._client.connect(vessel.address) self._transport = self._client.get_transport() self._transport.set_keepalive(10) self._sftp = self._client.open_sftp() def _exists(self, path: Union[str, Path]) -> bool: """Check if a path exists on the Vessel. Symlinks are not followed. Args: path (str, pathlib.Path): Path to check on the vessel Returns: bool: True if the path exists on the Vessel, else False """ try: self._sftp.stat(str(path)) return True except FileNotFoundError: return False def _isdir(self, path: Union[str, Path]) -> bool: """Check if a path is a directory on the Vessel. Symlinks are followed. Args: path (str, pathlib.Path): Path to check on the vessel Returns: bool: True if the path provided is a directory on the Vessel, False if it is a different kind of file. Raises: FileNotFoundError: Raised if the path does not exist on the Vessel """ return stat.S_ISDIR(self._sftp.lstat(str(path)).st_mode) def _mkdir(self, path: Union[str, Path]) -> None: """Create new directory on the Vessel Args: path (str, pathlib.Path): Path at which to create a new directory on the Vessel Raises: IOError: Raised if the directory cannot be created """ self._sftp.mkdir(str(path)) def _listdir(self, path: Optional[Union[str, Path]] = None) -> list[Optional[str]]: """List files in a directory on the Vessel Args: path (str, pathlib.Path, optional): Path at which to list contents. Will use current working directory if None. Defaults to None. Returns: list: List of the names of files (str) located at the provided path """ return self._sftp.listdir(str(path) if path else None) def _remove(self, path: Union[str, Path]) -> None: """Remove a file from the Vessel Args: path (str, pathlib.Path): Path of the file to delete Raises: FileNotFoundError: Raised if no file is found at the given path IOError: Raised if the file cannot be deleted """ return self._sftp.remove(str(path)) def assertDirectories(self, directory) -> None: """Make sure that destination and temp directories exist on the Vessel Args: directory (classes.directory.Directory): Directory object representing the directory to check Raises: ValueError: Raised if a path is already in use on the vessel but not a directory. IOError: Raised if a directory that does not exist cannot be created. """ for d in [directory, self._vessel.tempdir]: if not self._exists(d): self._mkdir(d) elif not self._isdir(d): raise ValueError( f"{d} exists but is not a directory on Vessel {self._vessel.name}!") def assertChunkComplete(self, chunk, path: Optional[Union[str, Path]] = None) -> bool: """Check if a Chunk has been uploaded correctly Args: chunk (classes.chunk.Chunk): Chunk object to verify upload for path (str, pathlib.Path, optional): Optional path at which to check. If None, will get default path from Chunk object. Defaults to None. Returns: bool: True if file has been uploaded correctly, else False """ path = path or self._vessel.tempdir / chunk.getTempName() if self._exists(path): # "-b" should not be required, but makes sure to use binary mode _, o, _ = self._client.exec_command("sha256sum -b " + str(path)) # Blocking for the command to complete o.channel.recv_exit_status() # Remove the file if it is broken if not o.readline().split()[0] == chunk.getHash(): self._remove(path) else: return True return False def pushChunk(self, chunk, path: Optional[Union[str, Path]] = None) -> None: """Push the content of a Chunk object to the Vessel Args: chunk (classes.chunk.Chunk): Chunk object containing the data to push to the Vessel path (str, pathlib.Path, optional): Path at which to store the Chunk on the Vessel. If None, use default location provided by Chunk object. Defaults to None. """ path = path or (self._vessel.tempdir / chunk.getTempName()) flo = BytesIO(chunk.data) self._sftp.putfo(flo, path, len(chunk.data)) def compileComplete(self, remotefile) -> None: """Build a complete File from uploaded Chunks. Args: remotefile (classes.remotefile.RemoteFile): RemoteFile object describing the uploaded File """ numchunks = remotefile.getStatus() + 1 # Get files in correct order to concatenate files = " ".join( [str(self._vessel.tempdir / f"{remotefile.file.uuid}_{i}.part") for i in range(numchunks)]) completefile = remotefile.file.getChunk(-1) outname = completefile.getTempName() outpath = self._vessel.tempdir / outname _, o, _ = self._client.exec_command(f"cat {files} > {outpath}") # Block for command to complete o.channel.recv_exit_status() def assertComplete(self, remotefile, allow_retry: bool = False) -> bool: """Check if File has been reassembled from Chunks correctly Args: remotefile (classes.remotefile.RemoteFile): RemoteFile object describing the uploaded File allow_retry (bool, optional): If True, assume that compileComplete failed for some other reason than corrupt Chunks, and only delete compiled file, else clear entire temporary directory. Defaults to False. Returns: bool: True if file was reassembled correctly, else False """ completefile = remotefile.file.getChunk(-1) outname = completefile.getTempName() outpath = self._vessel.tempdir / outname if not self._exists(outpath): return False if not self.assertChunkComplete(completefile): if allow_retry: self._remove(outpath) else: self.clearTempDir() return False return True def moveComplete(self, remotefile) -> None: """Moves reassembled file to output destination Args: remotefile (classes.remotefile.RemoteFile): RemoteFile object describing the uploaded File. Returns: [type]: [description] """ completefile = remotefile.file.getChunk(-1) destination = remotefile.getFullPath() self._sftp.rename( str(self._vessel.tempdir / completefile.getTempName()), str(destination)) # Make sure that file has actually been created at destination self._sftp.stat(str(destination)) def getCurrentUploadUUID(self) -> Optional[str]: """Get UUID of file currently being uploaded Returns: str, optional: UUID of the File being uploaded, if any, else None """ for f in self._listdir(self._vessel.tempdir): if f.endswith(".part"): return f.split("_")[0] def clearTempDir(self) -> None: """Clean up the temporary directory on the Vessel """ for f in self._listdir(self._vessel.tempdir): self._remove(self._vessel.tempdir / f) def __del__(self): """Close SSH connection when ending Connection """ self._client.close()