Can you create a small example application that allows to reproduce your issue?

Do you get any errors or log entries?

the implement seems to expect a _switch_user header (same name than the query param), not a x_switch_user one.

@stof
thanks for reply, but I tried it too and it doesn't work as well

@OskarStark
I didn't have time to prepare example yet

In your security.yaml you can do it:

main:
          pattern: ^/
          switch_user:
              parameter: 'HTTP_X_SWITCH_USER'

In the listener there is: (Symfony\Component\Security\Http\Firewall\SwitchUserListener)

$username = $request->get($this->usernameParameter);
        if (null === $username || '' === $username) {
            $username = $request->headers->get($this->usernameParameter);
        }

why not do something close to that (to comply with the doc):

$username = $request->get($this->usernameParameter);
        if (null === $username || '' === $username) {
            $username = $request->headers->get($this->usernameParameter, $request->headers->get('HTTP_X_SWITCH_USER'));
        }

The documentation is weird on this point. As ServerBag removes HTTP_ prefixes from server variables, you have to provide, with the default configuration a _Switch-User header.

Which translate to $_SERVER['HTTP__SWITCH_USER'] (note the double _ here).

If you configure parameter: HTTP_X_SWITCH_USER (which translate to $_SERVER['HTTP_HTTP_X_SWITCH_USER), you have to send a Http-X-Switch-User header to get impersonation working.

I used to configure parameter: x_switch_user so I can use X-Switch-User header.

yep, works for me too if, in my config :

   switch_user:
            parameter: X-Switch-User

PS : If you use nelmios_cors, think to update the config too :

nelmio_cors:
    defaults:
        origin_regex: true
        allow_origin: ['%env(CORS_ALLOW_ORIGIN)%']
        allow_methods: ['GET', 'OPTIONS', 'POST', 'PUT', 'PATCH', 'DELETE']
        allow_headers: ['Authorization', 'x-switch-user']
        

Hi there! Is someone willing to submit a pull request to the documentation to add the small configuration example shared by @Gu3 in the header tip?

closing here as this rather looks like a documentation issue