request_id 引き回し

nginx.conf

worker_processes  1;

events {
    worker_connections  1024;
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for" "$_request_id"';

    # 80
    #################################################
    server {
        listen 80;

        include ../conf.d/x_request_id.conf;
        access_log  logs/access1.log  main;
        # add_header X-Request-ID $_request_id;

        location / {
            proxy_pass http://backend/fake;
            proxy_set_header X-Request-ID $_request_id;
        }
    }
    
    # local proxy fakeserver
    #################################################
    server {
        listen 127.0.0.2:8080;

        include ../conf.d/x_request_id.conf;
        access_log logs/access2.log  main;
        # add_header X-Request-ID $_request_id;

        location = /fake {
            echo "this is the fake backend peer...";
        }
    }
    upstream backend {
        server 127.0.0.2:8080;
    }
}

x_request_id.conf

set $_request_id $request_id;
if ($http_x_request_id) {
    set $_request_id $http_x_request_id;
}