NGINX proxy for Prometheus to add scrape request header for disabling tracing

prometheus-nginx.yml

---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: prometheus-nginx
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: prometheus-nginx
    spec:
      containers:
      - image: nginx:latest
        name: prometheus-nginx
        ports:
        - name: web
          containerPort: 9191
          protocol: TCP
        volumeMounts:
        - mountPath: "/etc/nginx"
          name: config
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
          limits:
            cpu: 500m
            memory: 2500Mi
      volumes:
      - emptyDir: {}
        name: data
      - configMap:
          name: prometheus-nginx
        name: config
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-nginx
data:
  nginx.conf: |
    http {
      proxy_http_version 1.1;
      map $request $targetport {
        ~^GET\ http://.*:([^/]*)/ "$1";
      }
      server {
        listen 0.0.0.0:9191;
        location / {
          proxy_redirect off;
          proxy_set_header X-B3-Sampled 0;
          proxy_pass  $scheme://$host:$targetport$request_uri;
        }
      }
    }
    events {
    }
---
apiVersion: v1
kind: Service
metadata:
  name: prometheus-nginx
spec:
  type: LoadBalancer
  ports:
  - name: web
    nodePort: 30910
    port: 9191
    protocol: TCP
    targetPort: web
  selector:
    app: prometheus-nginx