[Django] #32891: runserver serve static files cached in debug
Django
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Reporter: TZanke | Owner: nobody
Type: Bug | Status: new
Component: contrib.staticfiles | Version: 3.2
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 1
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 1
UI/UX: 0 |
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Hello,
right now i experience a problem with runserver and serving static files.
1) open chrome
2) open F12 debug tools
2) start runserver (Debug True)
3) open django site with a js/css required in head
4) have a look at a js/css file in network tab of debugger. At first the
css/js file is loaded with status code 200, on F5 press maybe chrome just
checks again an gets a 304. Fine. But sometime (at least 80% of the time)
chrome does not check the server file again. I dont know why chrome does
not refreshes the file every time when 'just' F5 is pressed. CTRL+F5 will
fix the issue, but i think runserver with Debug=True should care about
this problem itself to allow fast and easy development of js/css.
Possible fix: Add `add_never_cache_headers` to the `static.py` `serve`
method
Right now i am not able to check the problem and fix on the latest version
of Django, is there any simple way to setup a Django Environment with
master branch to revalidate this issue?
Merge request on github: https://github.com/django/django/pull/14571
Right now i am not aware of all your django related requirements for
submitting a code change / pull request / commit message / tests so please
be gentle and take my pull request just as a possible example how to fix
the issue. I know there is a lot more work to do.
Best regards
Tobias
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Ticket URL: <https://code.djangoproject.com/ticket/32891>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: TZanke | Owner: TZanke
Type: Bug | Status: assigned
Component: contrib.staticfiles | Version: 3.2
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Changes (by Wu Haotian):
* owner: nobody => TZanke
* status: new => assigned
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Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:1>
Django
Reporter: TZanke | Owner: TZanke
Component: contrib.staticfiles | Version: 3.2
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Changes (by Carlton Gibson):
* status: assigned => closed
* resolution: => wontfix
Comment:
Hi Tobias — Welcome aboard!
> Possible fix: Add add_never_cache_headers to the static.py serve method
I don't think this is the right approach. As far as I can see the browser
behaviour is correct and as desired, serving static assets from the
browser cache when possible.
When working on a file this behaviour can be undesired. For that all the
browsers allow disabling the caches (at least while the dev tools are
open) by accessing the settings (normally via the little cog or hamburger
menu on in the dev tools, or via the Develop menu in Safari). If you check
this static assets are fetched on each request.
If you **really** wanted to add no cache headers you could do so in a
middleware, but I don't think it's appropriate for projects in general.
I hope that makes sense.
--
Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:2>
Django
Reporter: TZanke | Owner: TZanke
Type: Bug | Status: closed
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Comment (by TZanke):
Hello Carlton,
my (and my coworkers) expected behavior, with DEBUG=True, was a non-cached
js/css file. So while developing, new colleges always struggle debugging,
cause "my files does not get refreshed, but debug is on! Help me!". Yeah
no problem, we always use the "disable browser cache" but maybe we are not
alone with this problem, and this could easily be fixed. Cause `static.py
serve` only is used in Debug mode by Django.
But we will respect the decision made.
> If you really wanted to add no cache headers you could do so in a
middleware, but I don't think it's appropriate for projects in general.
I've tried, but its not working. `static.py serve` is called within the
'StaticFilesHandler', skipping the Middlewares from `BaseHandler`.
See:
https://github.com/django/django/blob/main/django/contrib/staticfiles/handlers.py#L53
No super call, no Middleware execution.
But keep in mind, i am not able to test with a new Django version right
now. Maybe i am wrong 'just lookin at github'. But in Django 1.11
Middlewares are skipped.
(And yees, we are are nearly finished with Python3 conversion, so Django
2/3 is coming...soon ;)
Best regards
Tobias
--
Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:3>
Django
Reporter: TZanke | Owner: TZanke
Type: Bug | Status: closed
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Comment (by Carlton Gibson):
Hi Tobias.
> ... is called within the 'StaticFilesHandler'...
Yes, of course. (Doh.)
In that case using the browser dev tools to disable caching is the way to
go.
Thanks.
--
Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:4>
Django
Reporter: TZanke | Owner: TZanke
Component: contrib.staticfiles | Version: 3.2
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Changes (by Dan Swain):
* status: closed => new
* resolution: wontfix =>
Comment:
I would like to revisit this issue and make a distinction between static
assets held by the Django site vs CDN-delivered content. Using the
Disable cache option in the Network tab of developer tools DOES accomplish
reloading static assets, BUT it causes ALL static assets to be reloaded
including CDN-delivered content. I like to set up libraries to be
delivered via CDN, even in development mode. Therefore, I would like to
see runserver deliver new versions of ONLY the static assets that are
housed in the Django project but NOT the CDN-delivered content. This
behavior would allow development to continue even if an Internet
connection is interrupted since CDN-delivered content would always be
pulled from the cache. If this behavior is not the desired default for
runserver (though I can't see why it wouldn't be), then perhaps a flag
such as ''--always-refresh-static'' would be in order to trigger this
behavior.
Finally, I know that I could use a bundler such as Vite or Snowpack to do
hot reloading of static files, but I'm not currently using a bundler and
so would like to see the above-described behavior included with runserver.
--
Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:5>
Django
Reporter: TZanke | Owner: TZanke
Component: contrib.staticfiles | Version: 3.2
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Changes (by Mariusz Felisiak):
* status: new => closed
* resolution: => wontfix
Comment:
I appreciate you'd like to reopen the ticket, but please
[https://docs.djangoproject.com/en/stable/internals/contributing/triaging-
tickets/#closing-tickets follow the triaging guidelines with regards to
wontfix tickets] and take this to DevelopersMailingList.
--
Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:6>
Django
Reporter: TZanke | Owner: TZanke
Type: Bug | Status: closed
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Comment (by Ole Laursen):
I just ran into this ticket - I have the reverse problem, I'd like the
static serve to send out a cache forever header, since I have a cache
buster in place (it appends ?_=[timestamp of file] to all references to
static assets). So it would be nice if I could get rid of the HTTP spam
from the 304s.
Perhaps a compromise could be a relatively easy way of setting the static
cache headers? Like:
{{{
re_path(r'^static/(?P<path>.*)$', django.views.static.serve,
{'document_root': settings.STATIC_ROOT, 'cache_control': {'no_store':True,
'max_age': 0}}),
}}}
I'm currently using a wrapper like this:
{{{
def static_serve_with_forever_cache(request, *args, **kwargs):
response = django.views.static.serve(request, *args, **kwargs)
if '_' in request.GET:
patch_cache_control(response, public=True, max_age=365 * 24 * 60 *
60, immutable=True)
return response
}}}
So it's not a big deal. But it is somewhat of a foot gun, so explicit
support with a little note in the documentation might be useful?
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Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:7>
Django
Reporter: TZanke | Owner: TZanke
Type: Bug | Status: closed
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Comment (by Mariusz Felisiak):
#33148 was marked as a duplicate of this ticket.
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Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:8>
Django
Reporter: TZanke | Owner: TZanke
Type: Bug | Status: closed
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Comment (by Carlton Gibson):
Same topic was also in #27572. There's a simple wrapper for `static.serve`
in https://code.djangoproject.com/ticket/27572#comment:4
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Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:9>
Django
Reporter: TZanke | Owner: TZanke
Type: Bug | Status: closed
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Comment (by Kevin Christopher Henry):
This issue is being discussed in the [https://forum.djangoproject.com/t
/static-files-served-in-development-should-not-be-cached/18579 Django
Forum].
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Ticket URL: <https://code.djangoproject.com/ticket/32891#comment:10>