K8S healthchecking nginx proxy

events {
  worker_connections  1024;  ## Default: 1024
}

http {
  include       /etc/nginx/mime.types;
  default_type  application/octet-stream;

  access_log off;
  error_log /dev/stdout;
  resolver kube-dns.kube-system.svc.cluster.local valid=5s;

  charset             utf-8;
  keepalive_timeout   65;
  server_tokens       off;
  sendfile            on;
  tcp_nopush          on;
  tcp_nodelay         off;

  server {
    listen 80;
    proxy_read_timeout 10s;


    location = /healthcheck {
      return 200 '{"ok": true, "nginx": true}';
      add_header Content-Type application/json;
    }

    # Internal services with non-default ports (NodePorts, for example) are proxied by /:name/:port
    location ~ /([a-zA-Z0-9_-]+)/(\d+) {
      proxy_pass http://$1.default.svc.cluster.local:$2/healthcheck;
    }

    # Internal services with default HTTP port are proxied by /:name
    location ~ /([a-zA-Z0-9_-]+) {
      proxy_pass http://$1.default.svc.cluster.local/healthcheck;
    }
  }
}