node-exporter.json

{
  "service": {
    "name": "node-exporter",
    "port": 9100
  }
}

prometheus-tag.yml

scrape_configs:
  - job_name: services
    metrics_path: /metrics
    scheme: http
    consul_sd_configs:
    - server: "consul.service.consul:8500"
        scheme: "http"
        tag:    "metrics"

prometheus.yaml

scrape_configs:
  - job_name: services
    metrics_path: /metrics
    scheme: http
    consul_sd_configs:
      - server: "consul.service.consul:8500"
        scheme: "http"
        services:
          - node-exporter