Fix NGINX Propagation

In this step, you'll **edit** the edge gateway NGINX configuration to forward W3C Trace Context headers, then **redeploy** the gateway so the change takes effect. That restores correlation between Splunk RUM and your backend APM traces for the order path.

Browser
  → Frontend NGINX (port 30080, NodePort)
    → frontend-api (Node.js BFF)
      → Edge Gateway NGINX (ClusterIP service gateway:80)   ← We are applying the fixes here
        → order-api:3001

Apply the Fix #

We now need to add explicit forwarding for the three W3C context headers in each location block:

These directives tell NGINX to pass the incoming trace context from the client (Splunk RUM) through to the upstream service.

Open and edit the gateway-config file:

cd ~/workshop/context-propagation
vi deploy/k8s/gateway-config.yaml 

Locate the location /api/ block inside the default.conf section (the indented NGINX config under data:) and add explicit forwarding for the three W3C context headers after the standard proxy_set_header lines and before proxy_http_version / proxy_pass

proxy_set_header traceparent $http_traceparent;
proxy_set_header tracestate $http_tracestate;
proxy_set_header baggage $http_baggage;

        location /api/ {
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_http_version 1.1;
            proxy_pass http://order_api;
        }

        location /api/ {
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

            # W3C Trace Context propagation
            proxy_set_header traceparent $http_traceparent;
            proxy_set_header tracestate $http_tracestate;
            proxy_set_header baggage $http_baggage;

            proxy_http_version 1.1;
            proxy_pass http://order_api;
        }

cp ./deploy/k8s/gateway-config-fixed.yaml ./deploy/k8s/gateway-config.yaml

diff ./deploy/k8s/gateway-config.yaml  ./deploy/k8s/gateway-config-fixed.yaml