Opened 4 years ago
Closed 4 years ago
#2055 closed defect (wontfix)
Using addition_filter and changing the added file: still returning "304 Not Modified"
| Reported by: | Owned by: | ||
|---|---|---|---|
| Priority: | minor | Milestone: | |
| Component: | nginx-module | Version: | 1.19.x |
| Keywords: | Cc: | ||
| uname -a: | Linux kondenzator 5.3.0-59-generic #53~18.04.1-Ubuntu SMP Thu Jun 4 14:58:26 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux | ||
| nginx -V: |
a@kondenzator:~[1]$ /tmp/nginx/objs/nginx -V
nginx version: nginx/1.19.3 built by gcc 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04) configure arguments: --with-http_addition_module a@kondenzator:~[0]$ |
||
Description
Hello!
I have just stumbled upon a nginx bug. When using add_before_body and/or add_after_body commands from ngx_http_addition_filter_module, the server will respond with "304 Not Modified" even if the added file has changed.
After investigation I figured out that this error could be applied to everything that uses ngx_http_subrequest to gather data. The request structure will remain with the same last_modified_time even if the subrequest contains data that was modified after this time. The solution to this problem would be to overwrite the request structure headers_out.last_modified_time with the last_modified_time in the structure, generated by ngx_http_subrequest, if it's in the future, but that would not be enough.
The problem is that ngx_http_subrequest does not populate the request struct, specified as it's fourth argument, with headers_out.last_modified_time, it stays at -1, but that wouldn't help very much in this particular case.
Even setting the headers_out.last_modified_time to -1 in addition_filter_module would not work and would not fix the issue, because the filter modules do not execute before not_modified module (nginx/auto/modules:142).
Well, at last resort, the not_modified module could load configuration of addition_filter module and, if addition is to be done, return to the next module. But that would not work either; the not_modified module source is included before the addition_filter so it's module struct and relying configurations are not available at the time of compilation.
Proof of bug: Run nginx with attached nginx.conf and create files /tmp/add.html and /tmp/index.html with some content. Load http://localhost:8080/ in a modern Firefox browser. Then change the file /tmp/add.html and nginx will proceed to report "304 Not Modified" and your browser's copy will after page refresh remain with the old /tmp/add.html file added at the beginning of the response.
Regards!
Attachments (1)
Change History (3)
by , 4 years ago
| Attachment: | nginx.conf added |
|---|
comment:1 by , 4 years ago
comment:2 by , 4 years ago
| Component: | documentation → nginx-module |
|---|---|
| Resolution: | → wontfix |
| Status: | new → closed |
That's the expected behaviour of the addition filter, as it is expected to be used for non-essential additions. See detailed response here.
Sorry, but it looks like I've incorrectly tagged the "component" property of this ticket with "documentation". Moderators, please change it to the appropriate value.
Thanks!