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|
# This file is part of cloud-init. See LICENSE file for license information.
import json
import logging
import math
from unittest import mock
import pytest
import requests
from cloudinit.sources.azure import imds
from cloudinit.url_helper import UrlError
MOCKPATH = "cloudinit.sources.azure.imds."
@pytest.fixture
def mock_readurl():
with mock.patch(MOCKPATH + "readurl", autospec=True) as m:
yield m
@pytest.fixture
def mock_requests_session_request():
with mock.patch("requests.Session.request", autospec=True) as m:
yield m
@pytest.fixture
def mock_url_helper_time_sleep():
with mock.patch("cloudinit.url_helper.time.sleep", autospec=True) as m:
yield m
def fake_http_error_for_code(status_code: int):
response_failure = requests.Response()
response_failure.status_code = status_code
return requests.exceptions.HTTPError(
"fake error",
response=response_failure,
)
class TestFetchMetadataWithApiFallback:
default_url = (
"http://169.254.169.254/metadata/instance?"
"api-version=2021-08-01&extended=true"
)
fallback_url = (
"http://169.254.169.254/metadata/instance?api-version=2019-06-01"
)
headers = {"Metadata": "true"}
retries = 10
timeout = 2
def test_basic(
self,
caplog,
mock_readurl,
):
fake_md = {"foo": {"bar": []}}
mock_readurl.side_effect = [
mock.Mock(contents=json.dumps(fake_md).encode()),
]
md = imds.fetch_metadata_with_api_fallback()
assert md == fake_md
assert mock_readurl.mock_calls == [
mock.call(
self.default_url,
timeout=self.timeout,
headers=self.headers,
retries=self.retries,
exception_cb=imds._readurl_exception_callback,
infinite=False,
log_req_resp=True,
),
]
warnings = [
x.message for x in caplog.records if x.levelno == logging.WARNING
]
assert warnings == []
def test_basic_fallback(
self,
caplog,
mock_readurl,
):
fake_md = {"foo": {"bar": []}}
mock_readurl.side_effect = [
UrlError("No IMDS version", code=400),
mock.Mock(contents=json.dumps(fake_md).encode()),
]
md = imds.fetch_metadata_with_api_fallback()
assert md == fake_md
assert mock_readurl.mock_calls == [
mock.call(
self.default_url,
timeout=self.timeout,
headers=self.headers,
retries=self.retries,
exception_cb=imds._readurl_exception_callback,
infinite=False,
log_req_resp=True,
),
mock.call(
self.fallback_url,
timeout=self.timeout,
headers=self.headers,
retries=self.retries,
exception_cb=imds._readurl_exception_callback,
infinite=False,
log_req_resp=True,
),
]
warnings = [
x.message for x in caplog.records if x.levelno == logging.WARNING
]
assert warnings == [
"Failed to fetch metadata from IMDS: No IMDS version",
"Falling back to IMDS api-version: 2019-06-01",
]
@pytest.mark.parametrize(
"error",
[
fake_http_error_for_code(404),
fake_http_error_for_code(410),
fake_http_error_for_code(429),
fake_http_error_for_code(500),
requests.ConnectionError("Fake connection error"),
requests.Timeout("Fake connection timeout"),
],
)
def test_will_retry_errors(
self,
caplog,
mock_requests_session_request,
mock_url_helper_time_sleep,
error,
):
fake_md = {"foo": {"bar": []}}
mock_requests_session_request.side_effect = [
error,
mock.Mock(content=json.dumps(fake_md)),
]
md = imds.fetch_metadata_with_api_fallback()
assert md == fake_md
assert len(mock_requests_session_request.mock_calls) == 2
assert mock_url_helper_time_sleep.mock_calls == [mock.call(1)]
warnings = [
x.message for x in caplog.records if x.levelno == logging.WARNING
]
assert warnings == []
def test_will_retry_errors_on_fallback(
self,
caplog,
mock_requests_session_request,
mock_url_helper_time_sleep,
):
error = fake_http_error_for_code(400)
fake_md = {"foo": {"bar": []}}
mock_requests_session_request.side_effect = [
error,
fake_http_error_for_code(429),
mock.Mock(content=json.dumps(fake_md)),
]
md = imds.fetch_metadata_with_api_fallback()
assert md == fake_md
assert len(mock_requests_session_request.mock_calls) == 3
assert mock_url_helper_time_sleep.mock_calls == [mock.call(1)]
warnings = [
x.message for x in caplog.records if x.levelno == logging.WARNING
]
assert warnings == [
"Failed to fetch metadata from IMDS: fake error",
"Falling back to IMDS api-version: 2019-06-01",
]
@pytest.mark.parametrize(
"error",
[
fake_http_error_for_code(404),
fake_http_error_for_code(410),
fake_http_error_for_code(429),
fake_http_error_for_code(500),
requests.ConnectionError("Fake connection error"),
requests.Timeout("Fake connection timeout"),
],
)
def test_retry_until_failure(
self,
caplog,
mock_requests_session_request,
mock_url_helper_time_sleep,
error,
):
mock_requests_session_request.side_effect = [error] * (11)
with pytest.raises(UrlError) as exc_info:
imds.fetch_metadata_with_api_fallback()
assert exc_info.value.cause == error
assert len(mock_requests_session_request.mock_calls) == (
self.retries + 1
)
assert (
mock_url_helper_time_sleep.mock_calls
== [mock.call(1)] * self.retries
)
warnings = [
x.message for x in caplog.records if x.levelno == logging.WARNING
]
assert warnings == [f"Failed to fetch metadata from IMDS: {error!s}"]
@pytest.mark.parametrize(
"error",
[
fake_http_error_for_code(403),
fake_http_error_for_code(501),
],
)
def test_will_not_retry_errors(
self,
caplog,
mock_requests_session_request,
mock_url_helper_time_sleep,
error,
):
fake_md = {"foo": {"bar": []}}
mock_requests_session_request.side_effect = [
error,
mock.Mock(content=json.dumps(fake_md)),
]
with pytest.raises(UrlError) as exc_info:
imds.fetch_metadata_with_api_fallback()
assert exc_info.value.cause == error
assert len(mock_requests_session_request.mock_calls) == 1
assert mock_url_helper_time_sleep.mock_calls == []
warnings = [
x.message for x in caplog.records if x.levelno == logging.WARNING
]
assert warnings == [f"Failed to fetch metadata from IMDS: {error!s}"]
def test_non_json_repsonse(
self,
caplog,
mock_readurl,
):
mock_readurl.side_effect = [
mock.Mock(contents=b"bad data"),
]
with pytest.raises(ValueError):
imds.fetch_metadata_with_api_fallback()
assert mock_readurl.mock_calls == [
mock.call(
self.default_url,
timeout=self.timeout,
headers=self.headers,
retries=self.retries,
exception_cb=imds._readurl_exception_callback,
infinite=False,
log_req_resp=True,
),
]
warnings = [
x.message for x in caplog.records if x.levelno == logging.WARNING
]
assert warnings == [
(
"Failed to parse metadata from IMDS: "
"Expecting value: line 1 column 1 (char 0)"
)
]
class TestFetchReprovisionData:
url = (
"http://169.254.169.254/metadata/"
"reprovisiondata?api-version=2019-06-01"
)
headers = {"Metadata": "true"}
timeout = 2
def test_basic(
self,
caplog,
mock_readurl,
):
content = b"ovf content"
mock_readurl.side_effect = [
mock.Mock(contents=content),
]
ovf = imds.fetch_reprovision_data()
assert ovf == content
assert mock_readurl.mock_calls == [
mock.call(
self.url,
timeout=self.timeout,
headers=self.headers,
exception_cb=mock.ANY,
infinite=True,
log_req_resp=False,
),
]
assert caplog.record_tuples == [
(
"cloudinit.sources.azure.imds",
logging.DEBUG,
"Polled IMDS 1 time(s)",
)
]
@pytest.mark.parametrize(
"error",
[
fake_http_error_for_code(404),
fake_http_error_for_code(410),
],
)
@pytest.mark.parametrize("failures", [1, 5, 100, 1000])
def test_will_retry_errors(
self,
caplog,
mock_requests_session_request,
mock_url_helper_time_sleep,
error,
failures,
):
content = b"ovf content"
mock_requests_session_request.side_effect = [error] * failures + [
mock.Mock(content=content),
]
ovf = imds.fetch_reprovision_data()
assert ovf == content
assert len(mock_requests_session_request.mock_calls) == failures + 1
assert (
mock_url_helper_time_sleep.mock_calls == [mock.call(1)] * failures
)
wrapped_error = UrlError(
error,
code=error.response.status_code,
headers=error.response.headers,
url=self.url,
)
backoff_logs = [
(
"cloudinit.sources.azure.imds",
logging.INFO,
"Polling IMDS failed with exception: "
f"{wrapped_error!r} count: {i}",
)
for i in range(1, failures + 1)
if i == 1 or math.log2(i).is_integer()
]
assert caplog.record_tuples == backoff_logs + [
(
"cloudinit.url_helper",
logging.DEBUG,
mock.ANY,
),
(
"cloudinit.sources.azure.imds",
logging.DEBUG,
f"Polled IMDS {failures+1} time(s)",
),
]
@pytest.mark.parametrize(
"error",
[
fake_http_error_for_code(404),
fake_http_error_for_code(410),
],
)
@pytest.mark.parametrize("failures", [1, 5, 100, 1000])
@pytest.mark.parametrize(
"terminal_error",
[
requests.ConnectionError("Fake connection error"),
requests.Timeout("Fake connection timeout"),
],
)
def test_retry_until_failure(
self,
caplog,
mock_requests_session_request,
mock_url_helper_time_sleep,
error,
failures,
terminal_error,
):
mock_requests_session_request.side_effect = [error] * failures + [
terminal_error
]
with pytest.raises(UrlError) as exc_info:
imds.fetch_reprovision_data()
assert exc_info.value.cause == terminal_error
assert len(mock_requests_session_request.mock_calls) == (failures + 1)
assert (
mock_url_helper_time_sleep.mock_calls == [mock.call(1)] * failures
)
wrapped_error = UrlError(
error,
code=error.response.status_code,
headers=error.response.headers,
url=self.url,
)
backoff_logs = [
(
"cloudinit.sources.azure.imds",
logging.INFO,
"Polling IMDS failed with exception: "
f"{wrapped_error!r} count: {i}",
)
for i in range(1, failures + 1)
if i == 1 or math.log2(i).is_integer()
]
assert caplog.record_tuples == backoff_logs + [
(
"cloudinit.sources.azure.imds",
logging.INFO,
"Polling IMDS failed with exception: "
f"{exc_info.value!r} count: {failures+1}",
),
]
@pytest.mark.parametrize(
"error",
[
fake_http_error_for_code(403),
fake_http_error_for_code(501),
],
)
def test_will_not_retry_errors(
self,
caplog,
mock_requests_session_request,
mock_url_helper_time_sleep,
error,
):
fake_md = {"foo": {"bar": []}}
mock_requests_session_request.side_effect = [
error,
mock.Mock(content=json.dumps(fake_md)),
]
with pytest.raises(UrlError) as exc_info:
imds.fetch_reprovision_data()
assert exc_info.value.cause == error
assert len(mock_requests_session_request.mock_calls) == 1
assert mock_url_helper_time_sleep.mock_calls == []
assert caplog.record_tuples == [
(
"cloudinit.sources.azure.imds",
logging.INFO,
"Polling IMDS failed with exception: "
f"{exc_info.value!r} count: 1",
),
]
|
