Source code for django.views.debug

import functools
import itertools
import re
import sys
import types
import warnings
from pathlib import Path

from django.conf import settings
from django.http import Http404, HttpResponse, HttpResponseNotFound
from django.template import Context, Engine, TemplateDoesNotExist
from django.template.defaultfilters import pprint
from django.urls import resolve
from django.utils import timezone
from django.utils.datastructures import MultiValueDict
from django.utils.encoding import force_str
from django.utils.module_loading import import_string
from django.utils.regex_helper import _lazy_re_compile
from django.utils.version import PY311, get_docs_version

# Minimal Django templates engine to render the error templates
# regardless of the project's TEMPLATES setting. Templates are
# read directly from the filesystem so that the error handler
# works even if the template loader is broken.
    libraries={"i18n": "django.templatetags.i18n"},

def builtin_template_path(name):
    Return a path to a builtin template.

    Avoid calling this function at the module level or in a class-definition
    because __file__ may not exist, e.g. in frozen environments.
    return Path(__file__).parent / "templates" / name

class ExceptionCycleWarning(UserWarning):

class CallableSettingWrapper:
    Object to wrap callable appearing in settings.
    * Not to call in the debug page (#21345).
    * Not to break the debug page if the callable forbidding to set attributes

    def __init__(self, callable_setting):
        self._wrapped = callable_setting

    def __repr__(self):
        return repr(self._wrapped)

def technical_500_response(request, exc_type, exc_value, tb, status_code=500):
    Create a technical server error response. The last three arguments are
    the values returned from sys.exc_info() and friends.
    reporter = get_exception_reporter_class(request)(request, exc_type, exc_value, tb)
    if request.accepts("text/html"):
        html = reporter.get_traceback_html()
        return HttpResponse(html, status=status_code)
        text = reporter.get_traceback_text()
        return HttpResponse(
            text, status=status_code, content_type="text/plain; charset=utf-8"

def get_default_exception_reporter_filter():
    # Instantiate the default filter for the first time and cache it.
    return import_string(settings.DEFAULT_EXCEPTION_REPORTER_FILTER)()

def get_exception_reporter_filter(request):
    default_filter = get_default_exception_reporter_filter()
    return getattr(request, "exception_reporter_filter", default_filter)

def get_exception_reporter_class(request):
    default_exception_reporter_class = import_string(
    return getattr(
        request, "exception_reporter_class", default_exception_reporter_class

def get_caller(request):
    resolver_match = request.resolver_match
    if resolver_match is None:
            resolver_match = resolve(request.path)
        except Http404:
    return "" if resolver_match is None else resolver_match._func_path

[docs]class SafeExceptionReporterFilter: """ Use annotations made by the sensitive_post_parameters and sensitive_variables decorators to filter out sensitive information. """ cleansed_substitute = "********************" hidden_settings = _lazy_re_compile( "API|TOKEN|KEY|SECRET|PASS|SIGNATURE|HTTP_COOKIE", flags=re.I ) def cleanse_setting(self, key, value): """ Cleanse an individual setting key/value of sensitive content. If the value is a dictionary, recursively cleanse the keys in that dictionary. """ if key == settings.SESSION_COOKIE_NAME: is_sensitive = True else: try: is_sensitive = except TypeError: is_sensitive = False if is_sensitive: cleansed = self.cleansed_substitute elif isinstance(value, dict): cleansed = {k: self.cleanse_setting(k, v) for k, v in value.items()} elif isinstance(value, list): cleansed = [self.cleanse_setting("", v) for v in value] elif isinstance(value, tuple): cleansed = tuple([self.cleanse_setting("", v) for v in value]) else: cleansed = value if callable(cleansed): cleansed = CallableSettingWrapper(cleansed) return cleansed def get_safe_settings(self): """ Return a dictionary of the settings module with values of sensitive settings replaced with stars (*********). """ settings_dict = {} for k in dir(settings): if k.isupper(): settings_dict[k] = self.cleanse_setting(k, getattr(settings, k)) return settings_dict def get_safe_request_meta(self, request): """ Return a dictionary of request.META with sensitive values redacted. """ if not hasattr(request, "META"): return {} return {k: self.cleanse_setting(k, v) for k, v in request.META.items()} def get_safe_cookies(self, request): """ Return a dictionary of request.COOKIES with sensitive values redacted. """ if not hasattr(request, "COOKIES"): return {} return {k: self.cleanse_setting(k, v) for k, v in request.COOKIES.items()}
[docs] def is_active(self, request): """ This filter is to add safety in production environments (i.e. DEBUG is False). If DEBUG is True then your site is not safe anyway. This hook is provided as a convenience to easily activate or deactivate the filter on a per request basis. """ return settings.DEBUG is False
def get_cleansed_multivaluedict(self, request, multivaluedict): """ Replace the keys in a MultiValueDict marked as sensitive with stars. This mitigates leaking sensitive POST parameters if something like request.POST['nonexistent_key'] throws an exception (#21098). """ sensitive_post_parameters = getattr(request, "sensitive_post_parameters", []) if self.is_active(request) and sensitive_post_parameters: multivaluedict = multivaluedict.copy() for param in sensitive_post_parameters: if param in multivaluedict: multivaluedict[param] = self.cleansed_substitute return multivaluedict
[docs] def get_post_parameters(self, request): """ Replace the values of POST parameters marked as sensitive with stars (*********). """ if request is None: return {} else: sensitive_post_parameters = getattr( request, "sensitive_post_parameters", [] ) if self.is_active(request) and sensitive_post_parameters: cleansed = request.POST.copy() if sensitive_post_parameters == "__ALL__": # Cleanse all parameters. for k in cleansed: cleansed[k] = self.cleansed_substitute return cleansed else: # Cleanse only the specified parameters. for param in sensitive_post_parameters: if param in cleansed: cleansed[param] = self.cleansed_substitute return cleansed else: return request.POST
def cleanse_special_types(self, request, value): try: # If value is lazy or a complex object of another kind, this check # might raise an exception. isinstance checks that lazy # MultiValueDicts will have a return value. is_multivalue_dict = isinstance(value, MultiValueDict) except Exception as e: return "{!r} while evaluating {!r}".format(e, value) if is_multivalue_dict: # Cleanse MultiValueDicts (request.POST is the one we usually care about) value = self.get_cleansed_multivaluedict(request, value) return value
[docs] def get_traceback_frame_variables(self, request, tb_frame): """ Replace the values of variables marked as sensitive with stars (*********). """ # Loop through the frame's callers to see if the sensitive_variables # decorator was used. current_frame = tb_frame.f_back sensitive_variables = None while current_frame is not None: if ( current_frame.f_code.co_name == "sensitive_variables_wrapper" and "sensitive_variables_wrapper" in current_frame.f_locals ): # The sensitive_variables decorator was used, so we take note # of the sensitive variables' names. wrapper = current_frame.f_locals["sensitive_variables_wrapper"] sensitive_variables = getattr(wrapper, "sensitive_variables", None) break current_frame = current_frame.f_back cleansed = {} if self.is_active(request) and sensitive_variables: if sensitive_variables == "__ALL__": # Cleanse all variables for name in tb_frame.f_locals: cleansed[name] = self.cleansed_substitute else: # Cleanse specified variables for name, value in tb_frame.f_locals.items(): if name in sensitive_variables: value = self.cleansed_substitute else: value = self.cleanse_special_types(request, value) cleansed[name] = value else: # Potentially cleanse the request and any MultiValueDicts if they # are one of the frame variables. for name, value in tb_frame.f_locals.items(): cleansed[name] = self.cleanse_special_types(request, value) if ( tb_frame.f_code.co_name == "sensitive_variables_wrapper" and "sensitive_variables_wrapper" in tb_frame.f_locals ): # For good measure, obfuscate the decorated function's arguments in # the sensitive_variables decorator's frame, in case the variables # associated with those arguments were meant to be obfuscated from # the decorated function's frame. cleansed["func_args"] = self.cleansed_substitute cleansed["func_kwargs"] = self.cleansed_substitute return cleansed.items()
[docs]class ExceptionReporter: """Organize and coordinate reporting on exceptions.""" @property def html_template_path(self): return builtin_template_path("technical_500.html") @property def text_template_path(self): return builtin_template_path("technical_500.txt") def __init__(self, request, exc_type, exc_value, tb, is_email=False): self.request = request self.filter = get_exception_reporter_filter(self.request) self.exc_type = exc_type self.exc_value = exc_value self.tb = tb self.is_email = is_email self.template_info = getattr(self.exc_value, "template_debug", None) self.template_does_not_exist = False self.postmortem = None def _get_raw_insecure_uri(self): """ Return an absolute URI from variables available in this request. Skip allowed hosts protection, so may return insecure URI. """ return "{scheme}://{host}{path}".format( scheme=self.request.scheme, host=self.request._get_raw_host(), path=self.request.get_full_path(), )
[docs] def get_traceback_data(self): """Return a dictionary containing traceback information.""" if self.exc_type and issubclass(self.exc_type, TemplateDoesNotExist): self.template_does_not_exist = True self.postmortem = self.exc_value.chain or [self.exc_value] frames = self.get_traceback_frames() for i, frame in enumerate(frames): if "vars" in frame: frame_vars = [] for k, v in frame["vars"]: v = pprint(v) # Trim large blobs of data if len(v) > 4096: v = "%s… <trimmed %d bytes string>" % (v[0:4096], len(v)) frame_vars.append((k, v)) frame["vars"] = frame_vars frames[i] = frame unicode_hint = "" if self.exc_type and issubclass(self.exc_type, UnicodeError): start = getattr(self.exc_value, "start", None) end = getattr(self.exc_value, "end", None) if start is not None and end is not None: unicode_str = self.exc_value.args[1] unicode_hint = force_str( unicode_str[max(start - 5, 0) : min(end + 5, len(unicode_str))], "ascii", errors="replace", ) from django import get_version if self.request is None: user_str = None else: try: user_str = str(self.request.user) except Exception: # request.user may raise OperationalError if the database is # unavailable, for example. user_str = "[unable to retrieve the current user]" c = { "is_email": self.is_email, "unicode_hint": unicode_hint, "frames": frames, "request": self.request, "request_meta": self.filter.get_safe_request_meta(self.request), "request_COOKIES_items": self.filter.get_safe_cookies(self.request).items(), "user_str": user_str, "filtered_POST_items": list( self.filter.get_post_parameters(self.request).items() ), "settings": self.filter.get_safe_settings(), "sys_executable": sys.executable, "sys_version_info": "%d.%d.%d" % sys.version_info[0:3], "server_time":, "django_version_info": get_version(), "sys_path": sys.path, "template_info": self.template_info, "template_does_not_exist": self.template_does_not_exist, "postmortem": self.postmortem, } if self.request is not None: c["request_GET_items"] = self.request.GET.items() c["request_FILES_items"] = self.request.FILES.items() c["request_insecure_uri"] = self._get_raw_insecure_uri() c["raising_view_name"] = get_caller(self.request) # Check whether exception info is available if self.exc_type: c["exception_type"] = self.exc_type.__name__ if self.exc_value: c["exception_value"] = str(self.exc_value) if exc_notes := getattr(self.exc_value, "__notes__", None): c["exception_notes"] = "\n" + "\n".join(exc_notes) if frames: c["lastframe"] = frames[-1] return c
[docs] def get_traceback_html(self): """Return HTML version of debug 500 HTTP error page.""" with"utf-8") as fh: t = DEBUG_ENGINE.from_string( c = Context(self.get_traceback_data(), use_l10n=False) return t.render(c)
[docs] def get_traceback_text(self): """Return plain text version of debug 500 HTTP error page.""" with"utf-8") as fh: t = DEBUG_ENGINE.from_string( c = Context(self.get_traceback_data(), autoescape=False, use_l10n=False) return t.render(c)
def _get_source(self, filename, loader, module_name): source = None if hasattr(loader, "get_source"): try: source = loader.get_source(module_name) except ImportError: pass if source is not None: source = source.splitlines() if source is None: try: with open(filename, "rb") as fp: source = except OSError: pass return source def _get_lines_from_file( self, filename, lineno, context_lines, loader=None, module_name=None ): """ Return context_lines before and after lineno from file. Return (pre_context_lineno, pre_context, context_line, post_context). """ source = self._get_source(filename, loader, module_name) if source is None: return None, [], None, [] # If we just read the source from a file, or if the loader did not # apply tokenize.detect_encoding to decode the source into a # string, then we should do that ourselves. if isinstance(source[0], bytes): encoding = "ascii" for line in source[:2]: # File coding may be specified. Match pattern from PEP-263 # ( match ="coding[:=]\s*([-\w.]+)", line) if match: encoding = match[1].decode("ascii") break source = [str(sline, encoding, "replace") for sline in source] lower_bound = max(0, lineno - context_lines) upper_bound = lineno + context_lines try: pre_context = source[lower_bound:lineno] context_line = source[lineno] post_context = source[lineno + 1 : upper_bound] except IndexError: return None, [], None, [] return lower_bound, pre_context, context_line, post_context def _get_explicit_or_implicit_cause(self, exc_value): explicit = getattr(exc_value, "__cause__", None) suppress_context = getattr(exc_value, "__suppress_context__", None) implicit = getattr(exc_value, "__context__", None) return explicit or (None if suppress_context else implicit) def get_traceback_frames(self): # Get the exception and all its causes exceptions = [] exc_value = self.exc_value while exc_value: exceptions.append(exc_value) exc_value = self._get_explicit_or_implicit_cause(exc_value) if exc_value in exceptions: warnings.warn( "Cycle in the exception chain detected: exception '%s' " "encountered again." % exc_value, ExceptionCycleWarning, ) # Avoid infinite loop if there's a cyclic reference (#29393). break frames = [] # No exceptions were supplied to ExceptionReporter if not exceptions: return frames # In case there's just one exception, take the traceback from self.tb exc_value = exceptions.pop() tb = self.tb if not exceptions else exc_value.__traceback__ while True: frames.extend(self.get_exception_traceback_frames(exc_value, tb)) try: exc_value = exceptions.pop() except IndexError: break tb = exc_value.__traceback__ return frames def get_exception_traceback_frames(self, exc_value, tb): exc_cause = self._get_explicit_or_implicit_cause(exc_value) exc_cause_explicit = getattr(exc_value, "__cause__", True) if tb is None: yield { "exc_cause": exc_cause, "exc_cause_explicit": exc_cause_explicit, "tb": None, "type": "user", } while tb is not None: # Support for __traceback_hide__ which is used by a few libraries # to hide internal frames. if tb.tb_frame.f_locals.get("__traceback_hide__"): tb = tb.tb_next continue filename = tb.tb_frame.f_code.co_filename function = tb.tb_frame.f_code.co_name lineno = tb.tb_lineno - 1 loader = tb.tb_frame.f_globals.get("__loader__") module_name = tb.tb_frame.f_globals.get("__name__") or "" ( pre_context_lineno, pre_context, context_line, post_context, ) = self._get_lines_from_file( filename, lineno, 7, loader, module_name, ) if pre_context_lineno is None: pre_context_lineno = lineno pre_context = [] context_line = "<source code not available>" post_context = [] colno = tb_area_colno = "" if PY311: _, _, start_column, end_column = next( itertools.islice( tb.tb_frame.f_code.co_positions(), tb.tb_lasti // 2, None ) ) if start_column and end_column: underline = "^" * (end_column - start_column) spaces = " " * (start_column + len(str(lineno + 1)) + 2) colno = f"\n{spaces}{underline}" tb_area_spaces = " " * ( 4 + start_column - (len(context_line) - len(context_line.lstrip())) ) tb_area_colno = f"\n{tb_area_spaces}{underline}" yield { "exc_cause": exc_cause, "exc_cause_explicit": exc_cause_explicit, "tb": tb, "type": "django" if module_name.startswith("django.") else "user", "filename": filename, "function": function, "lineno": lineno + 1, "vars": self.filter.get_traceback_frame_variables( self.request, tb.tb_frame ), "id": id(tb), "pre_context": pre_context, "context_line": context_line, "post_context": post_context, "pre_context_lineno": pre_context_lineno + 1, "colno": colno, "tb_area_colno": tb_area_colno, } tb = tb.tb_next
def technical_404_response(request, exception): """Create a technical 404 error response. `exception` is the Http404.""" try: error_url = exception.args[0]["path"] except (IndexError, TypeError, KeyError): error_url = request.path_info[1:] # Trim leading slash try: tried = exception.args[0]["tried"] except (IndexError, TypeError, KeyError): resolved = True tried = request.resolver_match.tried if request.resolver_match else None else: resolved = False if not tried or ( # empty URLconf request.path == "/" and len(tried) == 1 and len(tried[0]) == 1 # default URLconf and getattr(tried[0][0], "app_name", "") == getattr(tried[0][0], "namespace", "") == "admin" ): return default_urlconf(request) urlconf = getattr(request, "urlconf", settings.ROOT_URLCONF) if isinstance(urlconf, types.ModuleType): urlconf = urlconf.__name__ with builtin_template_path("technical_404.html").open(encoding="utf-8") as fh: t = DEBUG_ENGINE.from_string( reporter_filter = get_default_exception_reporter_filter() c = Context( { "urlconf": urlconf, "root_urlconf": settings.ROOT_URLCONF, "request_path": error_url, "urlpatterns": tried, "resolved": resolved, "reason": str(exception), "request": request, "settings": reporter_filter.get_safe_settings(), "raising_view_name": get_caller(request), } ) return HttpResponseNotFound(t.render(c)) def default_urlconf(request): """Create an empty URLconf 404 error response.""" with builtin_template_path("default_urlconf.html").open(encoding="utf-8") as fh: t = DEBUG_ENGINE.from_string( c = Context( { "version": get_docs_version(), } ) return HttpResponse(t.render(c))
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