Write access to /tmp folder in php container for applications needing sessions

[netsuo]

In one of my projects I was encountering some performance problems and I needed to install Blackfire.

After adding the PHP Probe, my API endpoint stopped to work and while researching the cause I found out that Blackfire was requesting write access to the container's /tmp folder for the sessions.

You have 2 ways of resolving the issue, the first involves changing Symfony's config to write sessions to /var/logs/sessions following Symfony's documentation like the following:

    session:
        handler_id: session.handler.native_file
        save_path: '%kernel.project_dir%/var/sessions/%kernel.environment%'

The second one is modifying the Dockerfile for the php container by adding RUN chmod 777 -R /tmp && chmod o+t -R /tmp before the end of the file. I put it right before the line where it copies the docker-entrypoint script.

Not sure if it's too specific to add to the distribution's default file but it might be fine because I don't think it interferes with anything else. I think the second solution is the best one because it does not modify the default Symfony config.

I would be happy to do a PR but I never made one so a bit of help would be great.

[gries]

Ot seems to be a very specific problem that can be solved by a User(Developer) by just changing the configuration.
It's a good practice to keep REST-API's stateless if one has a use-case where they need sessions the distribution can be easily changed.
It therefore think that session's should not be supported by default in the distribution.

[netsuo]

It's not only about sessions but everything that would need access to /tmp, let's say writing temporary files for file uploads

[gries]

That's actually a good point 👍

[Simperfit]

It may be to specific for me to add into the distribution.

@api-platform/core-team WDYT ?