404 error while submitting request

[volodymyrss]

experienced by @rokroskar , was not seen/report recently by anyone else, hard to track, bad experiene

edit: we'll wait for extra details

[volodymyrss]

it happens while using https://www.astro.unige.ch/mmoda and not https://www.astro.unige.ch/mmoda/. It's kind of critical @burnout87 @motame

[motame]

It's not clear !
Where is this link used ? (https://www.astro.unige.ch/mmoda)

[volodymyrss]

It's not clear ! Where is this link used ? (https://www.astro.unige.ch/mmoda)

it could be typed or used randomly by anyone. It actually opens the frontend. But the request to dispatcher is not correct.

edit: I meant, if this link is used to access frontend, no requests to dispatcher from the apparently normal frontend session can work

[motame]

Typing https://www.astro.unige.ch/mmoda in a browser returns the right content.
Would you describe a scenario ?

[volodymyrss]

Typing https://www.astro.unige.ch/mmoda in a browser returns the right content. Would you describe a scenario ?

that's why it's deceptive. In this "right" content, it is not possible to submit an request. Try "submit"

[motame]

Ah Ok, I see !

[motame]

I'm on it ...

[motame]

In fact, I've never seen it because my apache config is adding the trailing slash once the user press enter :-)
https://cdcidev.mtmco.net/mmoda
I'm trying to desactivate this on my dev instance ;)

[motame]

The issue is more complex than expected as discussed in the last meeting (30/01/2023).
On my dev instance, the module mod_dir of apache is enabled (as recommended).
By default it does redirect URLs of directories without a trailing slash to the ones with a slash !
Example:
It does redirect https://cdcidev.mtmco.net/mmoda to https://cdcidev.mtmco.net/mmoda/
The first request with https://cdcidev.mtmco.net/mmoda returns a redirect (status code 301) to https://cdcidev.mtmco.net/mmoda/ which is then requested by the browser.
This behavior is controlled by a directive called DirectorySlash.

• Description: Toggle trailing slash redirects on or off
• Syntax: DirectorySlash On|Off|NotFound
• Default: DirectorySlash On

<Location "/some/path">
  DirectorySlash Off
  SetHandler some-handler
</Location>

In mod_dir documentation it's not recommended to set this parameter to Off. They pointout to security warning.

Even it's recommended to have a trailing slash for URLs pointing to directories, it does not matter to have it or not. Search engines do handle properly both URLs. However it's highly recommended to not return the content for both but choose one as canonical and redirect the second to the first one.
There are situations were the returned content may be different and then both URLs may be indexed and visit statistics will be spread between the two.
More details in the article "To slash or not to slash" written by a former Developer Programs Tech Lead, Maile Ohye.

In the light of the above, I recommend to use the URL with a trailing slash (https://cdcidev.mtmco.net/mmoda/) as the canonical one and redirect the one without (https://cdcidev.mtmco.net/mmoda) to it. This can be easily achieved by enabling the Apache module mod_dir (in the case of Apache web server).