proxy_pass之后我可以从响应中读取或获取http标头吗？

Question

location /example {
    --set some header or do something by lua--
    ...
    proxy_pass http://someapp/;
    ...
    -- get some response header after proxy_pass and do something by lua--
}

有可能吗？，我如何得到一些回应？

真诚