import io
import logging
import os
import time
import urllib.parse
import urllib.request
import urllib.error
import urllib3
import sys
from itertools import chain, product
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing import Any
from typing import Callable
from typing import Dict
from typing import Optional
from typing import Self
from sentry_sdk.utils import (
logger as sentry_logger,
env_to_bool,
capture_internal_exceptions,
)
from sentry_sdk.envelope import Envelope
logger = logging.getLogger("spotlight")
DEFAULT_SPOTLIGHT_URL = "http://localhost:8969/stream"
DJANGO_SPOTLIGHT_MIDDLEWARE_PATH = "sentry_sdk.spotlight.SpotlightMiddleware"
class SpotlightClient:
"""
A client for sending envelopes to Sentry Spotlight.
Implements exponential backoff retry logic per the SDK spec:
- Logs error at least once when server is unreachable
- Does not log for every failed envelope
- Uses exponential backoff to avoid hammering an unavailable server
- Never blocks normal Sentry operation
"""
# Exponential backoff settings
INITIAL_RETRY_DELAY = 1.0 # Start with 1 second
MAX_RETRY_DELAY = 60.0 # Max 60 seconds
def __init__(self, url: str) -> None:
self.url = url
self.http = urllib3.PoolManager()
self._retry_delay = self.INITIAL_RETRY_DELAY
self._last_error_time: float = 0.0
def capture_envelope(self, envelope: "Envelope") -> None:
# Check if we're in backoff period - skip sending to avoid blocking
if self._last_error_time > 0:
time_since_error = time.time() - self._last_error_time
if time_since_error < self._retry_delay:
# Still in backoff period, skip this envelope
return
body = io.BytesIO()
envelope.serialize_into(body)
try:
req = self.http.request(
url=self.url,
body=body.getvalue(),
method="POST",
headers={
"Content-Type": "application/x-sentry-envelope",
},
)
req.close()
# Success - reset backoff state
self._retry_delay = self.INITIAL_RETRY_DELAY
self._last_error_time = 0.0
except Exception as e:
self._last_error_time = time.time()
# Increase backoff delay exponentially first, so logged value matches actual wait
self._retry_delay = min(self._retry_delay * 2, self.MAX_RETRY_DELAY)
# Log error once per backoff cycle (we skip sends during backoff, so only one failure per cycle)
sentry_logger.warning(
"Failed to send envelope to Spotlight at %s: %s. "
"Will retry after %.1f seconds.",
self.url,
e,
self._retry_delay,
)
try:
from django.utils.deprecation import MiddlewareMixin
from django.http import HttpResponseServerError, HttpResponse, HttpRequest
from django.conf import settings
SPOTLIGHT_JS_ENTRY_PATH = "/assets/main.js"
SPOTLIGHT_JS_SNIPPET_PATTERN = (
"\n"
'\n'
)
SPOTLIGHT_ERROR_PAGE_SNIPPET = (
'\n'
'\n'
)
CHARSET_PREFIX = "charset="
BODY_TAG_NAME = "body"
BODY_CLOSE_TAG_POSSIBILITIES = tuple(
"{}>".format("".join(chars))
for chars in product(*zip(BODY_TAG_NAME.upper(), BODY_TAG_NAME.lower()))
)
class SpotlightMiddleware(MiddlewareMixin): # type: ignore[misc]
_spotlight_script: "Optional[str]" = None
_spotlight_url: "Optional[str]" = None
def __init__(self: "Self", get_response: "Callable[..., HttpResponse]") -> None:
super().__init__(get_response)
import sentry_sdk.api
self.sentry_sdk = sentry_sdk.api
spotlight_client = self.sentry_sdk.get_client().spotlight
if spotlight_client is None:
sentry_logger.warning(
"Cannot find Spotlight client from SpotlightMiddleware, disabling the middleware."
)
return None
# Spotlight URL has a trailing `/stream` part at the end so split it off
self._spotlight_url = urllib.parse.urljoin(spotlight_client.url, "../")
@property
def spotlight_script(self: "Self") -> "Optional[str]":
if self._spotlight_url is not None and self._spotlight_script is None:
try:
spotlight_js_url = urllib.parse.urljoin(
self._spotlight_url, SPOTLIGHT_JS_ENTRY_PATH
)
req = urllib.request.Request(
spotlight_js_url,
method="HEAD",
)
urllib.request.urlopen(req)
self._spotlight_script = SPOTLIGHT_JS_SNIPPET_PATTERN.format(
spotlight_url=self._spotlight_url,
spotlight_js_url=spotlight_js_url,
)
except urllib.error.URLError as err:
sentry_logger.debug(
"Cannot get Spotlight JS to inject at %s. SpotlightMiddleware will not be very useful.",
spotlight_js_url,
exc_info=err,
)
return self._spotlight_script
def process_response(
self: "Self", _request: "HttpRequest", response: "HttpResponse"
) -> "Optional[HttpResponse]":
content_type_header = tuple(
p.strip()
for p in response.headers.get("Content-Type", "").lower().split(";")
)
content_type = content_type_header[0]
if len(content_type_header) > 1 and content_type_header[1].startswith(
CHARSET_PREFIX
):
encoding = content_type_header[1][len(CHARSET_PREFIX) :]
else:
encoding = "utf-8"
if (
self.spotlight_script is not None
and not response.streaming
and content_type == "text/html"
):
content_length = len(response.content)
injection = self.spotlight_script.encode(encoding)
injection_site = next(
(
idx
for idx in (
response.content.rfind(body_variant.encode(encoding))
for body_variant in BODY_CLOSE_TAG_POSSIBILITIES
)
if idx > -1
),
content_length,
)
# This approach works even when we don't have a `` tag
response.content = (
response.content[:injection_site]
+ injection
+ response.content[injection_site:]
)
if response.has_header("Content-Length"):
response.headers["Content-Length"] = content_length + len(injection)
return response
def process_exception(
self: "Self", _request: "HttpRequest", exception: Exception
) -> "Optional[HttpResponseServerError]":
if not settings.DEBUG or not self._spotlight_url:
return None
try:
spotlight = (
urllib.request.urlopen(self._spotlight_url).read().decode("utf-8")
)
except urllib.error.URLError:
return None
else:
event_id = self.sentry_sdk.capture_exception(exception)
return HttpResponseServerError(
spotlight.replace(
"",
SPOTLIGHT_ERROR_PAGE_SNIPPET.format(
spotlight_url=self._spotlight_url, event_id=event_id
),
)
)
except ImportError:
settings = None
def _resolve_spotlight_url(
spotlight_config: "Any", sentry_logger: "Any"
) -> "Optional[str]":
"""
Resolve the Spotlight URL based on config and environment variable.
Implements precedence rules per the SDK spec:
https://develop.sentry.dev/sdk/expected-features/spotlight/
Returns the resolved URL string, or None if Spotlight should be disabled.
"""
spotlight_env_value = os.environ.get("SENTRY_SPOTLIGHT")
# Parse env var to determine if it's a boolean or URL
spotlight_from_env: "Optional[bool]" = None
spotlight_env_url: "Optional[str]" = None
if spotlight_env_value:
parsed = env_to_bool(spotlight_env_value, strict=True)
if parsed is None:
# It's a URL string
spotlight_from_env = True
spotlight_env_url = spotlight_env_value
else:
spotlight_from_env = parsed
# Apply precedence rules per spec:
# https://develop.sentry.dev/sdk/expected-features/spotlight/#precedence-rules
if spotlight_config is False:
# Config explicitly disables spotlight - warn if env var was set
if spotlight_from_env:
sentry_logger.warning(
"Spotlight is disabled via spotlight=False config option, "
"ignoring SENTRY_SPOTLIGHT environment variable."
)
return None
elif spotlight_config is True:
# Config enables spotlight with boolean true
# If env var has URL, use env var URL per spec
if spotlight_env_url:
return spotlight_env_url
else:
return DEFAULT_SPOTLIGHT_URL
elif isinstance(spotlight_config, str):
# Config has URL string - use config URL, warn if env var differs
if spotlight_env_value and spotlight_env_value != spotlight_config:
sentry_logger.warning(
"Spotlight URL from config (%s) takes precedence over "
"SENTRY_SPOTLIGHT environment variable (%s).",
spotlight_config,
spotlight_env_value,
)
return spotlight_config
elif spotlight_config is None:
# No config - use env var
if spotlight_env_url:
return spotlight_env_url
elif spotlight_from_env:
return DEFAULT_SPOTLIGHT_URL
# else: stays None (disabled)
return None
def setup_spotlight(options: "Dict[str, Any]") -> "Optional[SpotlightClient]":
url = _resolve_spotlight_url(options.get("spotlight"), sentry_logger)
if url is None:
return None
# Only set up logging handler when spotlight is actually enabled
_handler = logging.StreamHandler(sys.stderr)
_handler.setFormatter(logging.Formatter(" [spotlight] %(levelname)s: %(message)s"))
logger.addHandler(_handler)
logger.setLevel(logging.INFO)
# Update options with resolved URL for consistency
options["spotlight"] = url
with capture_internal_exceptions():
if (
settings is not None
and settings.DEBUG
and env_to_bool(os.environ.get("SENTRY_SPOTLIGHT_ON_ERROR", "1"))
and env_to_bool(os.environ.get("SENTRY_SPOTLIGHT_MIDDLEWARE", "1"))
):
middleware = settings.MIDDLEWARE
if DJANGO_SPOTLIGHT_MIDDLEWARE_PATH not in middleware:
settings.MIDDLEWARE = type(middleware)(
chain(middleware, (DJANGO_SPOTLIGHT_MIDDLEWARE_PATH,))
)
logger.info("Enabled Spotlight integration for Django")
client = SpotlightClient(url)
logger.info("Enabled Spotlight using sidecar at %s", url)
return client