Get Cloudflare's HTTP_CF_IPCOUNTRY header with javascript?

Question

There are many SO questions how to get http headers with javascript, but for some reason they don\'t show up HTTP_CF_IPCOUNTRY header.

If I try to do with php echo

Answer 1

@Quentin's answer stands correct and holds true for any javascript client trying to access server header's.

However, since this question is specific to Cloudlfare and specific to getting the 2 letter country ISO normally in the HTTP_CF_IPCOUNTRY header, I believe I have a work-around that best befits the question asked.

Below is a code excerpt that I use on my frontend Ember App, sitting behind Cloudflare... and varnish... and fastboot...

function parseTrace(url){
    let trace = [];
    $.ajax(url,
        {
            success: function(response){
                let lines = response.split('\n');
                let keyValue;

                lines.forEach(function(line){
                    keyValue = line.split('=');
                    trace[keyValue[0]] = decodeURIComponent(keyValue[1] || '');

                    if(keyValue[0] === 'loc' && trace['loc'] !== 'XX'){
                        alert(trace['loc']);
                    }

                    if(keyValue[0] === 'ip'){
                        alert(trace['ip']);
                    }

                });

                return trace;
            },
            error: function(){
                return trace;
            }
        }
    );
};

let cfTrace = parseTrace('/cdn-cgi/trace');

The performance is really really great, don't be afraid to call this function even before you call other APIs or functions. I have found it to be as quick or sometimes even quicker than retrieving static resources from Cloudflare's cache. You can run a profile on Pingdom to confirm this.