Lightweight Python 3+ client library for Kubernetes (pykube-ng)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

491 lines
17 KiB

HTTP request related code.
import base64
import datetime
import json
import logging
import os
import shlex
import subprocess
from typing import Optional
import google.auth
from google.auth.transport.requests import Request as GoogleAuthRequest
google_auth_installed = True
except ImportError:
google_auth_installed = False
from requests_oauthlib import OAuth2Session
oidc_auth_installed = True
except ImportError:
oidc_auth_installed = False
import requests.adapters
from http import HTTPStatus
from urllib.parse import urlparse
from .exceptions import HTTPError, PyKubeError
from .utils import jsonpath_installed, jsonpath_parse, join_url_path
from .config import KubeConfig
from . import __version__
EXPIRY_SKEW_PREVENTION_DELAY = datetime.timedelta(minutes=5)
UTC = datetime.timezone.utc
LOG = logging.getLogger(__name__)
class KubernetesHTTPAdapter(requests.adapters.HTTPAdapter):
# _do_send: the actual send method of HTTPAdapter
# it can be overwritten in unit tests to mock the actual HTTP calls
_do_send = requests.adapters.HTTPAdapter.send
def __init__(self, kube_config: KubeConfig, **kwargs):
self.kube_config = kube_config
def _persist_credentials(self, config, opts):
user_name = config.contexts[config.current_context]["user"]
user = [u["user"] for u in config.doc["users"] if u["name"] == user_name][0]
auth_config = user["auth-provider"].setdefault("config", {})
def _auth_gcp(self, request, token, expiry, config):
original_request = request.copy()
credentials = google.auth.default(
credentials.token = token
credentials.expiry = expiry
should_persist = not credentials.valid
auth_request = GoogleAuthRequest()
auth_request, request.method, request.url, request.headers
if should_persist and config:
auth_opts = {
"access-token": credentials.token,
"expiry": credentials.expiry,
self._persist_credentials(config, auth_opts)
def retry(send_kwargs):
response = self.send(original_request, **send_kwargs)
if response.ok and config:
auth_opts = {
"access-token": credentials.token,
"expiry": credentials.expiry,
self._persist_credentials(config, auth_opts)
return response
return retry
def _is_valid_jwt(self, token):
"""Validate JWT token for correctness and near expiration"""
if not token:
return False
reserved_characters = frozenset(["=", "+", "/"])
if any(char in token for char in reserved_characters):
# Invalid jwt, as it contains url-unsafe chars
return False
parts = token.split(".")
if len(parts) != 3: # Not a valid JWT
return False
padding = (4 - len(parts[1]) % 4) * "="
if len(padding) == 3:
# According to spec, 3 padding characters cannot occur
# in a valid jwt
return False
jwt_attributes = json.loads(
base64.b64decode(parts[1] + padding).decode("utf-8")
expire = jwt_attributes.get("exp")
# allow missing exp, but deny tokens that are about to expire soon
return expire is None or (
datetime.datetime.fromtimestamp(expire, tz=UTC)
) > datetime.datetime.utcnow().replace(tzinfo=UTC)
def _refresh_oidc_token(self, config):
if not oidc_auth_installed:
raise ImportError(
"missing dependencies for OIDC token refresh support "
"(try pip install pykube-ng[oidc]"
auth_config = config.user["auth-provider"]["config"]
if "idp-certificate-authority" in auth_config:
verify = auth_config["idp-certificate-authority"].filename()
verify = None
oauth = OAuth2Session()
discovery = oauth.get(
if discovery.status_code != HTTPStatus.OK:
raise PyKubeError(
f"Failed to discover OpenID token endpoint - "
f"HTTP {discovery.status_code}: {discovery.text}"
discovery = discovery.json()
refresh = oauth.refresh_token(
auth_opts = {
"id-token": refresh["id_token"],
"refresh-token": refresh["refresh_token"],
self._persist_credentials(config, auth_opts)
def send(self, request, **kwargs):
if "kube_config" in kwargs:
config = kwargs.pop("kube_config")
config = self.kube_config
_retry_attempt = kwargs.pop("_retry_attempt", 0)
retry_func = self._setup_request_auth(config, request, kwargs)
self._setup_request_certificates(config, request, kwargs)
response = self._do_send(request, **kwargs)
_retry_status_codes = {HTTPStatus.UNAUTHORIZED}
if (
response.status_code in _retry_status_codes
and retry_func
and _retry_attempt < 2
send_kwargs = {"_retry_attempt": _retry_attempt + 1, "kube_config": config}
return retry_func(send_kwargs=send_kwargs)
return response
def _setup_request_auth(self, config, request, kwargs):
Set up authorization for the request.
Return an optional function to use as a retry manager if the initial request fails
with an unauthorized error.
if "Authorization" in request.headers:
# request already has some auth header (e.g. Bearer token)
# don't modify/overwrite it
return None
if config.user.get("token"):
request.headers["Authorization"] = "Bearer {}".format(config.user["token"])
return None
if "exec" in config.user:
exec_conf = config.user["exec"]
api_version = exec_conf["apiVersion"]
if api_version == "":
cmd_env_vars = dict(os.environ)
for env_var in exec_conf.get("env") or []:
cmd_env_vars[env_var["name"]] = env_var["value"]
output = subprocess.check_output(
[exec_conf["command"]] + exec_conf["args"], env=cmd_env_vars
parsed_out = json.loads(output)
token = parsed_out["status"]["token"]
raise NotImplementedError(
f"auth exec api version {api_version} not implemented"
request.headers["Authorization"] = "Bearer {}".format(token)
return None
if config.user.get("username") and config.user.get("password"):
request.prepare_auth((config.user["username"], config.user["password"]))
return None
if "auth-provider" in config.user:
auth_provider = config.user["auth-provider"]
if auth_provider.get("name") == "gcp":
dependencies = [google_auth_installed, jsonpath_installed]
if not all(dependencies):
raise ImportError(
"missing dependencies for GCP support (try pip install pykube-ng[gcp]"
auth_config = auth_provider.get("config", {})
if "cmd-path" in auth_config:
output = subprocess.check_output(
[auth_config["cmd-path"]] + shlex.split(auth_config["cmd-args"])
parsed = json.loads(output)
token = jsonpath_parse(auth_config["token-key"], parsed)
expiry = datetime.datetime.strptime(
jsonpath_parse(auth_config["expiry-key"], parsed),
retry_func = self._auth_gcp(request, token, expiry, None)
retry_func = self._auth_gcp(
return retry_func
elif auth_provider.get("name") == "oidc":
auth_config = auth_provider.get("config", {})
if not self._is_valid_jwt(auth_config.get("id-token")):
# ignoring all exceptions, rely on retries
except Exception as oidc_exc:
LOG.warning(f"Failed to refresh OpenID token: {oidc_exc}")
# not using auth_config handle here as the config might have
# been reloaded during token refresh
request.headers["Authorization"] = "Bearer {}".format(
return None
def _setup_request_certificates(self, config, request, kwargs):
if "client-certificate" in config.user:
kwargs["cert"] = (
# setup certificate verification
if "certificate-authority" in config.cluster:
kwargs["verify"] = config.cluster["certificate-authority"].filename()
elif "insecure-skip-tls-verify" in config.cluster:
kwargs["verify"] = not config.cluster["insecure-skip-tls-verify"]
class HTTPClient:
Client for interfacing with the Kubernetes API.
http_adapter_cls = KubernetesHTTPAdapter
def __init__(
config: KubeConfig,
timeout: float = DEFAULT_HTTP_TIMEOUT,
dry_run: bool = False,
verify: bool = True,
http_adapter: Optional[requests.adapters.HTTPAdapter] = None,
Creates a new instance of the HTTPClient.
- `config`: The configuration instance
self.config = config
self.timeout = timeout
self.url = self.config.cluster["server"]
self.dry_run = dry_run
session = requests.Session()
session.headers["User-Agent"] = f"pykube-ng/{__version__}"
if not http_adapter:
http_adapter = self.http_adapter_cls(self.config)
session.mount("https://", http_adapter)
session.mount("http://", http_adapter)
self.session = session
self.session.verify = verify
def url(self):
return self._url
def url(self, value):
pr = urlparse(value)
self._url = pr.geturl()
def version(self):
Get Kubernetes API version
response = self.get(version="", base="/version")
data = response.json()
return (data["major"], data["minor"])
def resource_list(self, api_version):
cached_attr = f"_cached_resource_list_{api_version}"
if not hasattr(self, cached_attr):
r = self.get(version=api_version)
setattr(self, cached_attr, r.json())
return getattr(self, cached_attr)
def get_kwargs(self, **kwargs) -> dict:
Creates a full URL to request based on arguments.
- `kwargs`: All keyword arguments to build a kubernetes API endpoint
version = kwargs.pop("version", "v1")
if version == "v1":
base = kwargs.pop("base", "/api")
elif "/" in version:
base = kwargs.pop("base", "/apis")
if "base" not in kwargs:
raise TypeError("unknown API version; base kwarg must be specified.")
base = kwargs.pop("base")
if version.startswith("/"):
# for compatibility with pykube-ng 20.1.0 when calling api.get(version="/apis"):
# posixpath.join() was throwing away everything before the first "absolute" path (i.e. starting with a slash)
bits = [version]
bits = [base, version]
# Overwrite (default) namespace from context if it was set
if "namespace" in kwargs:
n = kwargs.pop("namespace")
if n is not None:
if n:
namespace = n
namespace = self.config.namespace
if namespace:
bits.extend(["namespaces", namespace])
url = kwargs.get("url", "")
kwargs["url"] = self.url + join_url_path(*bits, join_empty=True)
if "timeout" not in kwargs:
# apply default HTTP timeout
kwargs["timeout"] = self.timeout
if self.dry_run:
# Add http query param for dryRun
params = kwargs.get("params", {})
params["dryRun"] = "All"
kwargs["params"] = params
return kwargs
def raise_for_status(self, resp):
except Exception:
# attempt to provide a more specific exception based around what
# Kubernetes returned as the error.
if resp.headers["content-type"] == "application/json":
payload = resp.json()
if payload["kind"] == "Status":
raise HTTPError(resp.status_code, payload["message"])
def request(self, *args, **kwargs):
Makes an API request based on arguments.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return self.session.request(*args, **self.get_kwargs(**kwargs))
def get(self, *args, **kwargs):
Executes an HTTP GET.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return self.session.get(*args, **self.get_kwargs(**kwargs))
def options(self, *args, **kwargs):
Executes an HTTP OPTIONS.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return self.session.options(*args, **self.get_kwargs(**kwargs))
def head(self, *args, **kwargs):
Executes an HTTP HEAD.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return self.session.head(*args, **self.get_kwargs(**kwargs))
def post(self, *args, **kwargs):
Executes an HTTP POST.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return*args, **self.get_kwargs(**kwargs))
def put(self, *args, **kwargs):
Executes an HTTP PUT.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return self.session.put(*args, **self.get_kwargs(**kwargs))
def patch(self, *args, **kwargs):
Executes an HTTP PATCH.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return self.session.patch(*args, **self.get_kwargs(**kwargs))
def delete(self, *args, **kwargs):
Executes an HTTP DELETE.
- `args`: Non-keyword arguments
- `kwargs`: Keyword arguments
return self.session.delete(*args, **self.get_kwargs(**kwargs))