Current File : //lib/python3/dist-packages/uaclient/serviceclient.py
import abc
import json
import os
from posixpath import join as urljoin
from typing import Any, Dict, Optional, Tuple, Type
from urllib import error
from urllib.parse import urlencode
from uaclient import config, exceptions, util, version
class UAServiceClient(metaclass=abc.ABCMeta):
url_timeout = None # type: Optional[int]
# Cached serviceclient_url_responses if provided in uaclient.conf
# via features: {serviceclient_url_responses: /some/file.json}
_response_overlay = None # type: Dict[str, Any]
@property
@abc.abstractmethod
def api_error_cls(self) -> Type[Exception]:
"""Set in subclasses to the type of API error raised"""
pass
@property
@abc.abstractmethod
def cfg_url_base_attr(self) -> str:
"""String in subclasses, the UAConfig attribute containing base url"""
pass
def __init__(self, cfg: Optional[config.UAConfig] = None) -> None:
if not cfg:
self.cfg = config.UAConfig()
else:
self.cfg = cfg
def headers(self):
return {
"user-agent": "UA-Client/{}".format(version.get_version()),
"accept": "application/json",
"content-type": "application/json",
}
def request_url(
self,
path,
data=None,
headers=None,
method=None,
query_params=None,
potentially_sensitive: bool = True,
):
path = path.lstrip("/")
if not headers:
headers = self.headers()
if headers.get("content-type") == "application/json" and data:
data = json.dumps(data).encode("utf-8")
url = urljoin(getattr(self.cfg, self.cfg_url_base_attr), path)
fake_response, fake_headers = self._get_fake_responses(url)
if fake_response:
return fake_response, fake_headers # URL faked by uaclient.conf
if query_params:
# filter out None values
filtered_params = {
k: v for k, v in sorted(query_params.items()) if v is not None
}
url += "?" + urlencode(filtered_params)
try:
response, headers = util.readurl(
url=url,
data=data,
headers=headers,
method=method,
timeout=self.url_timeout,
potentially_sensitive=potentially_sensitive,
)
except error.URLError as e:
body = None
if hasattr(e, "body"):
body = e.body # type: ignore
elif hasattr(e, "read"):
body = e.read().decode("utf-8") # type: ignore
if body:
try:
error_details = json.loads(
body, cls=util.DatetimeAwareJSONDecoder
)
except ValueError:
error_details = None
if error_details:
raise self.api_error_cls(e, error_details)
raise exceptions.UrlError(
e, code=getattr(e, "code", None), headers=headers, url=url
)
return response, headers
def _get_response_overlay(self, url: str):
"""Return a list of fake response dicts for a given URL.
serviceclient_url_responses in uaclient.conf should be a path
to a json file which contains a dictionary keyed by full URL path.
Each value will be a list of dicts representing each faked response
for the given URL.
The response dict item will have a code: <HTTP_STATUS_CODE> and
response: "some string of content".
The JSON string below fakes the available_resources URL on the
contract server:
'{"https://contracts.canonical.com/v1/resources": \
[{"code": 200, "response": {"key": "val1", "key2": "val2"}}]}'
:return: List of dicts for each faked response matching the url, or
and empty list when no matching url found.
"""
if self._response_overlay is not None:
# Cache it so we don't re-read config every readurl call
return self._response_overlay.get(url, [])
response_overlay_path = self.cfg.features.get(
"serviceclient_url_responses"
)
if not response_overlay_path:
self._response_overlay = {}
elif not os.path.exists(response_overlay_path):
self._response_overlay = {}
else:
self._response_overlay = json.loads(
util.load_file(response_overlay_path)
)
return self._response_overlay.get(url, [])
def _get_fake_responses(
self, url: str
) -> Tuple[Optional[Dict[str, Any]], Optional[Dict[str, str]]]:
"""Return response and headers if faked for this URL in uaclient.conf.
:return: A tuple of response and header dicts if the URL has an overlay
response defined. Return (None, {}) otherwise.
:raises exceptions.URLError: When faked response "code" is != 200.
URLError reason will be "response" value and any optional
"headers" provided.
"""
responses = self._get_response_overlay(url)
if not responses:
return None, {}
if len(responses) == 1:
# When only one respose is defined, repeat it for all calls
response = responses[0]
else:
# When multiple responses defined pop the first one off the list.
response = responses.pop(0)
if response["code"] == 200:
return response["response"], response.get("headers", {})
# Must be an error
e = error.URLError(response["response"])
raise exceptions.UrlError(
e,
code=response["code"],
headers=response.get("headers", {}),
url=url,
)
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