Description

This PR https://github.com/apache/apisix/pull/10589/files, introduced a bug due to which the request body is emptied after being read by the auth service and the upstream doesn't receive the request body. Therefore, this PR needs to be reverted.

The new solution after this revert is accepted will be:
Do not need to pass the whole request body to the auth service and extract data from body into headers and then forward to the auth service. The headers to be extracted will be specified with a new field: extra_headers

Fixes #11200

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)