Not All Headers Are Shown With Firebase OnRequest

I'm trying to learn Firebase while making a small project, where I need to store IP addresses in my system.

But I realized that it's not working like I'm used to work with Express. I need the exact same result of this Gist: https://gist.github.com/katowulf/6fffffb45ee5cbfbca6c3511e5d19528#gistcomment-2674393

However doing the same things doesn't work for me, I don't get so many headers and also not getting the client IP address.

exports.getPolls = functions.region('europe-west1').https.onRequest((req, res) => {
    console.log(util.format(req.headers))
});

Header's I get

headers:
   { host: 'localhost:5001',
     connection: 'keep-alive',
     'upgrade-insecure-requests': '1',
     'user-agent':
      'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3370.152 Safari/537.36',
     accept:
      'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3',
     'accept-encoding': 'gzip, deflate, br',
     'accept-language': 'en,nl;q=0.9,tr;q=0.8',
     cookie: 'io=AVNO7ouAHOYCkVK8ADSD',
     'if-none-match': 'W/"5-qvTGHdzV6LKavt4PO0gs2a6pQ00"' 
    },

I need the client IP address

This problem has been solved: https://github.com/firebase/firebase-functions/issues/541

Short explanation:

when doing firebase serve the request headers are coming from an emulator which has not the expected headers, firebase deploy is what you need to do.

Going to the firebase console > functions (choose your function) > logs, would show the expected headers (with the x-forwarded-for header) when you console log like me.