[PHP] 6.0.x make php implementation depend on meta packages for http client

[olexiyk]

Instead of relying on Guzzle directly, depend on a psr/http-client-implementation (AKA PSR 18). This is a metapackage which implementations can declare they provide, all the major ones already do (including Guzzle, Symfony, etc).

Inspired by discussion: #7518

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• [ x ] Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• [ x ] Run the following to build the project and update samples:

  ./mvnw clean package 
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  ./bin/utils/export_docs_generators.sh
  

  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
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• [ x ] File the PR against the correct branch: master, 5.1.x, 6.0.x
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@jebentier (2017/07), @dkarlovi (2017/07), @mandrean (2017/08), @jfastnacht (2017/09), @ackintosh (2017/09) ❤️, @ybelenko (2018/07), @renepardon (2018/12)

[dkarlovi]

This looks great, thanks for working on this! <3

Some questions I'd like to discuss:

[olexiyk]

Update from 2021-07-05 redirect problem was solved by upgrading php-http/client-common, PHP Unit tests are passing now

---

Some tests are failing and I figured out the reason, I don't have a solution for it yet.

http://petstore.swagger.io/v2 is a base url we are running tests against
any request to that host redirects to https://petstore.swagger.io/v2

The redirect plugin from here https://github.com/php-http/plugins/blob/master/src/RedirectPlugin.php#L197
when doing a redirect is updating method from POST to GET. In the end, the response to the second request is 405 Method not allowed.

I read a bit about that and to me it looks that probably RedirectPlugin should not change POST to GET, but that is a common implementation bug

https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3

If the 302 status code is received in response to a request other than GET or HEAD, the user agent MUST NOT automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued.

Note: RFC 1945 and RFC 2068 specify that the client is not allowed
to change the method on the redirected request. However, most
existing user agent implementations treat 302 as if it were a 303
response, performing a GET on the Location field-value regardless
of the original request method. The status codes 303 and 307 have
been added for servers that wish to make unambiguously clear which
kind of reaction is expected of the client.

As well seen at
https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/302

Even if the specification requires the method (and the body) not to be altered when the redirection is performed, not all user-agents conform here - you can still find this type of bugged software out there. It is therefore recommended to set the 302 code only as a response for GET or HEAD methods and to use 307 Temporary Redirect instead, as the method change is explicitly prohibited in that case.

I am not sure on how to solve that issue yet, I will get back to the PR after one week

[olexiyk]

Could you take a look again? The issue with redirect was fixed by using an updated php-http/client-common package. guzzlehttp/psr7 is now either ^1.8 or ^2.0 because the used classes are the same in both

I have seen that build was failing but could not really understand what exactly was wrong

[dkarlovi]

@wing328 is the issue with Petstore tests fixed? I remember it's quite flaky.

[hanovruslan]

Hi! Does this issue have some forecasts for release?

[Argentum88]

@dkarlovi @wing328 Are there any reasons for the merge delay?

[deluxetom]

it would be great to have this merged, let us know if help is needed

[wing328]

@olexiyk can you please resolve the merge conflicts when you've time?

[wing328]

UPDATE: I've filed #16368 to add the implementation via the library option (e.g. --library psr-18 via CLI)

[wing328]

Included #16368 in v7.0.0 release.