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# https://hadoop.apache.org/docs/r1.0.4/webhdfs.html | |
import logging | |
import os | |
import secrets | |
import shutil | |
import tempfile | |
import uuid | |
from contextlib import suppress | |
from urllib.parse import quote | |
import requests | |
from ..spec import AbstractBufferedFile, AbstractFileSystem | |
from ..utils import infer_storage_options, tokenize | |
logger = logging.getLogger("webhdfs") | |
class WebHDFS(AbstractFileSystem): | |
""" | |
Interface to HDFS over HTTP using the WebHDFS API. Supports also HttpFS gateways. | |
Four auth mechanisms are supported: | |
insecure: no auth is done, and the user is assumed to be whoever they | |
say they are (parameter ``user``), or a predefined value such as | |
"dr.who" if not given | |
spnego: when kerberos authentication is enabled, auth is negotiated by | |
requests_kerberos https://github.com/requests/requests-kerberos . | |
This establishes a session based on existing kinit login and/or | |
specified principal/password; parameters are passed with ``kerb_kwargs`` | |
token: uses an existing Hadoop delegation token from another secured | |
service. Indeed, this client can also generate such tokens when | |
not insecure. Note that tokens expire, but can be renewed (by a | |
previously specified user) and may allow for proxying. | |
basic-auth: used when both parameter ``user`` and parameter ``password`` | |
are provided. | |
""" | |
tempdir = str(tempfile.gettempdir()) | |
protocol = "webhdfs", "webHDFS" | |
def __init__( | |
self, | |
host, | |
port=50070, | |
kerberos=False, | |
token=None, | |
user=None, | |
password=None, | |
proxy_to=None, | |
kerb_kwargs=None, | |
data_proxy=None, | |
use_https=False, | |
session_cert=None, | |
session_verify=True, | |
**kwargs, | |
): | |
""" | |
Parameters | |
---------- | |
host: str | |
Name-node address | |
port: int | |
Port for webHDFS | |
kerberos: bool | |
Whether to authenticate with kerberos for this connection | |
token: str or None | |
If given, use this token on every call to authenticate. A user | |
and user-proxy may be encoded in the token and should not be also | |
given | |
user: str or None | |
If given, assert the user name to connect with | |
password: str or None | |
If given, assert the password to use for basic auth. If password | |
is provided, user must be provided also | |
proxy_to: str or None | |
If given, the user has the authority to proxy, and this value is | |
the user in who's name actions are taken | |
kerb_kwargs: dict | |
Any extra arguments for HTTPKerberosAuth, see | |
`<https://github.com/requests/requests-kerberos/blob/master/requests_kerberos/kerberos_.py>`_ | |
data_proxy: dict, callable or None | |
If given, map data-node addresses. This can be necessary if the | |
HDFS cluster is behind a proxy, running on Docker or otherwise has | |
a mismatch between the host-names given by the name-node and the | |
address by which to refer to them from the client. If a dict, | |
maps host names ``host->data_proxy[host]``; if a callable, full | |
URLs are passed, and function must conform to | |
``url->data_proxy(url)``. | |
use_https: bool | |
Whether to connect to the Name-node using HTTPS instead of HTTP | |
session_cert: str or Tuple[str, str] or None | |
Path to a certificate file, or tuple of (cert, key) files to use | |
for the requests.Session | |
session_verify: str, bool or None | |
Path to a certificate file to use for verifying the requests.Session. | |
kwargs | |
""" | |
if self._cached: | |
return | |
super().__init__(**kwargs) | |
self.url = f"{'https' if use_https else 'http'}://{host}:{port}/webhdfs/v1" # noqa | |
self.kerb = kerberos | |
self.kerb_kwargs = kerb_kwargs or {} | |
self.pars = {} | |
self.proxy = data_proxy or {} | |
if token is not None: | |
if user is not None or proxy_to is not None: | |
raise ValueError( | |
"If passing a delegation token, must not set " | |
"user or proxy_to, as these are encoded in the" | |
" token" | |
) | |
self.pars["delegation"] = token | |
self.user = user | |
self.password = password | |
if password is not None: | |
if user is None: | |
raise ValueError( | |
"If passing a password, the user must also be" | |
"set in order to set up the basic-auth" | |
) | |
else: | |
if user is not None: | |
self.pars["user.name"] = user | |
if proxy_to is not None: | |
self.pars["doas"] = proxy_to | |
if kerberos and user is not None: | |
raise ValueError( | |
"If using Kerberos auth, do not specify the " | |
"user, this is handled by kinit." | |
) | |
self.session_cert = session_cert | |
self.session_verify = session_verify | |
self._connect() | |
self._fsid = f"webhdfs_{tokenize(host, port)}" | |
def fsid(self): | |
return self._fsid | |
def _connect(self): | |
self.session = requests.Session() | |
if self.session_cert: | |
self.session.cert = self.session_cert | |
self.session.verify = self.session_verify | |
if self.kerb: | |
from requests_kerberos import HTTPKerberosAuth | |
self.session.auth = HTTPKerberosAuth(**self.kerb_kwargs) | |
if self.user is not None and self.password is not None: | |
from requests.auth import HTTPBasicAuth | |
self.session.auth = HTTPBasicAuth(self.user, self.password) | |
def _call(self, op, method="get", path=None, data=None, redirect=True, **kwargs): | |
url = self._apply_proxy(self.url + quote(path or "", safe="/=")) | |
args = kwargs.copy() | |
args.update(self.pars) | |
args["op"] = op.upper() | |
logger.debug("sending %s with %s", url, method) | |
out = self.session.request( | |
method=method.upper(), | |
url=url, | |
params=args, | |
data=data, | |
allow_redirects=redirect, | |
) | |
if out.status_code in [400, 401, 403, 404, 500]: | |
try: | |
err = out.json() | |
msg = err["RemoteException"]["message"] | |
exp = err["RemoteException"]["exception"] | |
except (ValueError, KeyError): | |
pass | |
else: | |
if exp in ["IllegalArgumentException", "UnsupportedOperationException"]: | |
raise ValueError(msg) | |
elif exp in ["SecurityException", "AccessControlException"]: | |
raise PermissionError(msg) | |
elif exp in ["FileNotFoundException"]: | |
raise FileNotFoundError(msg) | |
else: | |
raise RuntimeError(msg) | |
out.raise_for_status() | |
return out | |
def _open( | |
self, | |
path, | |
mode="rb", | |
block_size=None, | |
autocommit=True, | |
replication=None, | |
permissions=None, | |
**kwargs, | |
): | |
""" | |
Parameters | |
---------- | |
path: str | |
File location | |
mode: str | |
'rb', 'wb', etc. | |
block_size: int | |
Client buffer size for read-ahead or write buffer | |
autocommit: bool | |
If False, writes to temporary file that only gets put in final | |
location upon commit | |
replication: int | |
Number of copies of file on the cluster, write mode only | |
permissions: str or int | |
posix permissions, write mode only | |
kwargs | |
Returns | |
------- | |
WebHDFile instance | |
""" | |
block_size = block_size or self.blocksize | |
return WebHDFile( | |
self, | |
path, | |
mode=mode, | |
block_size=block_size, | |
tempdir=self.tempdir, | |
autocommit=autocommit, | |
replication=replication, | |
permissions=permissions, | |
) | |
def _process_info(info): | |
info["type"] = info["type"].lower() | |
info["size"] = info["length"] | |
return info | |
def _strip_protocol(cls, path): | |
return infer_storage_options(path)["path"] | |
def _get_kwargs_from_urls(urlpath): | |
out = infer_storage_options(urlpath) | |
out.pop("path", None) | |
out.pop("protocol", None) | |
if "username" in out: | |
out["user"] = out.pop("username") | |
return out | |
def info(self, path): | |
out = self._call("GETFILESTATUS", path=path) | |
info = out.json()["FileStatus"] | |
info["name"] = path | |
return self._process_info(info) | |
def ls(self, path, detail=False): | |
out = self._call("LISTSTATUS", path=path) | |
infos = out.json()["FileStatuses"]["FileStatus"] | |
for info in infos: | |
self._process_info(info) | |
info["name"] = path.rstrip("/") + "/" + info["pathSuffix"] | |
if detail: | |
return sorted(infos, key=lambda i: i["name"]) | |
else: | |
return sorted(info["name"] for info in infos) | |
def content_summary(self, path): | |
"""Total numbers of files, directories and bytes under path""" | |
out = self._call("GETCONTENTSUMMARY", path=path) | |
return out.json()["ContentSummary"] | |
def ukey(self, path): | |
"""Checksum info of file, giving method and result""" | |
out = self._call("GETFILECHECKSUM", path=path, redirect=False) | |
if "Location" in out.headers: | |
location = self._apply_proxy(out.headers["Location"]) | |
out2 = self.session.get(location) | |
out2.raise_for_status() | |
return out2.json()["FileChecksum"] | |
else: | |
out.raise_for_status() | |
return out.json()["FileChecksum"] | |
def home_directory(self): | |
"""Get user's home directory""" | |
out = self._call("GETHOMEDIRECTORY") | |
return out.json()["Path"] | |
def get_delegation_token(self, renewer=None): | |
"""Retrieve token which can give the same authority to other uses | |
Parameters | |
---------- | |
renewer: str or None | |
User who may use this token; if None, will be current user | |
""" | |
if renewer: | |
out = self._call("GETDELEGATIONTOKEN", renewer=renewer) | |
else: | |
out = self._call("GETDELEGATIONTOKEN") | |
t = out.json()["Token"] | |
if t is None: | |
raise ValueError("No token available for this user/security context") | |
return t["urlString"] | |
def renew_delegation_token(self, token): | |
"""Make token live longer. Returns new expiry time""" | |
out = self._call("RENEWDELEGATIONTOKEN", method="put", token=token) | |
return out.json()["long"] | |
def cancel_delegation_token(self, token): | |
"""Stop the token from being useful""" | |
self._call("CANCELDELEGATIONTOKEN", method="put", token=token) | |
def chmod(self, path, mod): | |
"""Set the permission at path | |
Parameters | |
---------- | |
path: str | |
location to set (file or directory) | |
mod: str or int | |
posix epresentation or permission, give as oct string, e.g, '777' | |
or 0o777 | |
""" | |
self._call("SETPERMISSION", method="put", path=path, permission=mod) | |
def chown(self, path, owner=None, group=None): | |
"""Change owning user and/or group""" | |
kwargs = {} | |
if owner is not None: | |
kwargs["owner"] = owner | |
if group is not None: | |
kwargs["group"] = group | |
self._call("SETOWNER", method="put", path=path, **kwargs) | |
def set_replication(self, path, replication): | |
""" | |
Set file replication factor | |
Parameters | |
---------- | |
path: str | |
File location (not for directories) | |
replication: int | |
Number of copies of file on the cluster. Should be smaller than | |
number of data nodes; normally 3 on most systems. | |
""" | |
self._call("SETREPLICATION", path=path, method="put", replication=replication) | |
def mkdir(self, path, **kwargs): | |
self._call("MKDIRS", method="put", path=path) | |
def makedirs(self, path, exist_ok=False): | |
if exist_ok is False and self.exists(path): | |
raise FileExistsError(path) | |
self.mkdir(path) | |
def mv(self, path1, path2, **kwargs): | |
self._call("RENAME", method="put", path=path1, destination=path2) | |
def rm(self, path, recursive=False, **kwargs): | |
self._call( | |
"DELETE", | |
method="delete", | |
path=path, | |
recursive="true" if recursive else "false", | |
) | |
def rm_file(self, path, **kwargs): | |
self.rm(path) | |
def cp_file(self, lpath, rpath, **kwargs): | |
with self.open(lpath) as lstream: | |
tmp_fname = "/".join([self._parent(rpath), f".tmp.{secrets.token_hex(16)}"]) | |
# Perform an atomic copy (stream to a temporary file and | |
# move it to the actual destination). | |
try: | |
with self.open(tmp_fname, "wb") as rstream: | |
shutil.copyfileobj(lstream, rstream) | |
self.mv(tmp_fname, rpath) | |
except BaseException: # noqa | |
with suppress(FileNotFoundError): | |
self.rm(tmp_fname) | |
raise | |
def _apply_proxy(self, location): | |
if self.proxy and callable(self.proxy): | |
location = self.proxy(location) | |
elif self.proxy: | |
# as a dict | |
for k, v in self.proxy.items(): | |
location = location.replace(k, v, 1) | |
return location | |
class WebHDFile(AbstractBufferedFile): | |
"""A file living in HDFS over webHDFS""" | |
def __init__(self, fs, path, **kwargs): | |
super().__init__(fs, path, **kwargs) | |
kwargs = kwargs.copy() | |
if kwargs.get("permissions", None) is None: | |
kwargs.pop("permissions", None) | |
if kwargs.get("replication", None) is None: | |
kwargs.pop("replication", None) | |
self.permissions = kwargs.pop("permissions", 511) | |
tempdir = kwargs.pop("tempdir") | |
if kwargs.pop("autocommit", False) is False: | |
self.target = self.path | |
self.path = os.path.join(tempdir, str(uuid.uuid4())) | |
def _upload_chunk(self, final=False): | |
"""Write one part of a multi-block file upload | |
Parameters | |
========== | |
final: bool | |
This is the last block, so should complete file, if | |
self.autocommit is True. | |
""" | |
out = self.fs.session.post( | |
self.location, | |
data=self.buffer.getvalue(), | |
headers={"content-type": "application/octet-stream"}, | |
) | |
out.raise_for_status() | |
return True | |
def _initiate_upload(self): | |
"""Create remote file/upload""" | |
kwargs = self.kwargs.copy() | |
if "a" in self.mode: | |
op, method = "APPEND", "POST" | |
else: | |
op, method = "CREATE", "PUT" | |
kwargs["overwrite"] = "true" | |
out = self.fs._call(op, method, self.path, redirect=False, **kwargs) | |
location = self.fs._apply_proxy(out.headers["Location"]) | |
if "w" in self.mode: | |
# create empty file to append to | |
out2 = self.fs.session.put( | |
location, headers={"content-type": "application/octet-stream"} | |
) | |
out2.raise_for_status() | |
# after creating empty file, change location to append to | |
out2 = self.fs._call("APPEND", "POST", self.path, redirect=False, **kwargs) | |
self.location = self.fs._apply_proxy(out2.headers["Location"]) | |
def _fetch_range(self, start, end): | |
start = max(start, 0) | |
end = min(self.size, end) | |
if start >= end or start >= self.size: | |
return b"" | |
out = self.fs._call( | |
"OPEN", path=self.path, offset=start, length=end - start, redirect=False | |
) | |
out.raise_for_status() | |
if "Location" in out.headers: | |
location = out.headers["Location"] | |
out2 = self.fs.session.get(self.fs._apply_proxy(location)) | |
return out2.content | |
else: | |
return out.content | |
def commit(self): | |
self.fs.mv(self.path, self.target) | |
def discard(self): | |
self.fs.rm(self.path) | |