Tag Archives: Prometheus

Web

Troubleshoot blackbox exporter errors

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I had a frustrating issue where prometheus blackbox exporter wasn’t able to check one of my websites and I couldn’t figure out why. I finally found this site which explained you can append &debug=true to the end of your probe in a URL string talking directly to blackbox. For example:

http://prometheus:9115/probe?module=http_2xx&target=http://customsite.com:8096/web/&debug=true

That finally got me to see what the problem was. It was resolving to an IPv6 address, but I didn’t have my IPv6 stack properly configured. I then discovered this site which led me to the solution: prefer IPv4. I appended this to my http_2xx config:

http_2xx:
  prober: http
  http:
    preferred_ip_protocol: ip4
...

That fixed the issue!

Networking

Prometheus dashboard for MB8611 cable modem statistics

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I’ve had issues with my cable internet service lately. I came across this excellent guide from Duckware to troubleshooting cable internet issues and realized my modem had all the information I needed to troubleshoot my connection. Calling the cable company is a complete waste of time. Fortunately I was able to fix it with some insight into what was going on. In my case, it ended up being a loose cable. I simply had to tighten every connection along the way with a simple tool.

In my troubleshooting I was on the hunt for a Prometheus exporter that would get the data from my cable modem, as manually getting it from the modem webpage is painful. The prometheus-moto-exporter was fairly straightforward to set up. I just needed a dashboard to actually view and interpret the data. There was reference to this project but it appears to have been deleted. I eventually found that at some point someone had forked it here. It got me mostly there, but there was a syntax error in the JSON, and it referred to the exported data by a different name. I was able to fix both issues and created my own fork, located here: https://github.com/jimmyface/prometheus-mb8611-dashboard (note: it looks like the original repo made a recent update fixing the quotation problem.)

It works! I now have a quick and easy way to interpret data from my cable modem, and it is beautiful.