Add HTTP header based on client Remote address

In a scenario we needed to add a custom http header to client http-request based on his IP address.

NGINX

This can be accomplished in two ways: the short and easily accessible approach is spine up a NGINX server with config (proxy.conf) you may find in the nginx directory. For more ease, you can run this command to run the new container for this propose.

You can find another config (default.conf) in the nginx directory which has a custom logging activated which will add this new custom HTTP header (route-tag) to the logs. I used this config for testing the scenario.

docker run -it -v  proxy.conf:/etc/nginx/conf.d/default.conf --rm -d -p 8081:80 --name proxy nginx

default.conf

log_format  debug     '$remote_addr - $http_route_tag - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for" "$http_x_xsrf_token"';


server {
    .
    .

    access_log /var/log/nginx/access.log  debug;
    .
    .

AWS Cloud Front by Terraform

But you may know about the limitations of this approach (scaling, CDN friendly, integrated in cloud...). So you may find aws-terraform directory Which will do the same in AWS CDN CloudFront. With a Cloudfront function for Viewer request the function is some line of code is JS as this is the default way to manipulate the HTTP Headers on the fly in CF. I didn't use Lambda@Edge because of its price, and of course It was nice handled by Cloudfront function.