title: Prometheus Federation match params do not work
body: <p>I have been trying to achive federation in my Prometheus setup. While doing this, I want to exclude some metrics to be scraped by my scraper Prometheus. </p>
  
  <p>Here is my federation config: </p>
  
  <pre><code>global:
    scrape_interval: 15s
  
  scrape_configs:
    - job_name: 'xxxxxxxx'
      scrape_interval: 15s
      honor_labels: true
      metrics_path: '/federate'
      params:
        'match[]':
          - '{job!="kubernetes-nodes"}'
      static_configs:
        - targets:
          - 'my-metrics-source'
  </code></pre>
  
  <p>As it can be seen from the config, I want to exclude any metric that has <code>kubernetes-nodes</code> <code>job</code> label, and retrieve the rest of the metrics. However, when I deploy my config, no metric is scraped. </p>
  
  <p>Is it a bug in Prometheus or I simply misunderstood how the match params work?</p>