I have written some exporters to observe things on GitHub. This is how and why. We will talk …
I live in Brazil, and, if you’re not familiar, internet usually sucks here.
I’m one of the lucky few that can afford a good internet, aka 1gbps.
But, I’m not used to trust telecom companies, so I measure my internet speed every 30m and store the results in a time-series database. This is how I did it.
Tales of an overengineered home
In any case, I run quite a bit of stuff there, but the important parts for this post are:
You can see all my terraform code for it in this repository.
Assuming you have Prometheus already running (if you don’t, you can install them using their Helm charts), running the exporter is quite easy as well:
apiVersion: apps/v1 kind: Deployment metadata: labels: app: speedtest-exporter name: speedtest-exporter namespace: prometheus spec: selector: matchLabels: app: speedtest-exporter template: metadata: labels: app: speedtest-exporter spec: containers: - name: exporter image: ghcr.io/caarlos0/speedtest-exporter:v1.0.0 ports: - containerPort: 9876 protocol: TCP livenessProbe: httpGet: path: / port: 9876 readinessProbe: httpGet: path: / port: 9876
apiVersion: v1 kind: Service metadata: annotations: prometheus.io/path: /metrics prometheus.io/port: "9876" prometheus.io/scrape: "true" labels: app: speedtest-exporter name: speedtest-exporter namespace: prometheus spec: ports: - port: 9876 protocol: TCP targetPort: 9876 selector: app: speedtest-exporter type: ClusterIP
The annotations on the service will be picked up by Prometheus, and it will start collecting the
/metrics endpoint of the exporter right away.
Ater testing a couple of already existing exporters, and disliking all of them for several different reasons, I decided to write one myself.
The implementation is basically:
speedtest-cliwith the needed flags
- parse the output
- emit metrics in the prometheus format
- cache results for N minutes (by default, 30m)
With that, I get a fresh Speedtest result every N minutes, and can graph them with Grafana.
Once the metrics are there, making a dashboard on my Grafana instance was a piece of cake.
You can import it in your own Grafana by informing the ID
14187 or following the instructions here.
As you can see, they are not delivering the promised speeds, so I’ll have to give them a call so they can tell me to restart my modem a couple of times and then “send an update to my modem” or something like that.
That being said, it useful to have a graph like this so I can see its not something intermittent or related to “high demand of business hours”, since we can clearly see its at
~850mpbs all the time, and bringing this kind of data when arguing with the providers sure helps.
I hope this can be somewhat useful for you as well.