chartsrv

chartsrv

chartsrv is a dead-simple web application which runs Prometheus queries and charts the result as an SVG. You make a dashboard by putting a lot of these images into a web page. You make it refresh by adding <meta id="refresh" http-equiv="refresh" content="5"> to the header. Ta-da!

This is a live graph from metrics.sr.ht

Running the daemon

$ go build -o chartsrv main.go
$ ./chartsrv https://prometheus.example.org
Listening on :8142

Forward /chart.svg to this address with your favorite reverse proxy. If you want to listen to some other port, pass a second argument like :1337.

Usage

Create a URL like https://chartsrv.example.org/chart.svg?query=...&args... and set the query parameters as appropriate:

• query: required. Prometheus query to execute.
• title: chart title
• stacked: set to create an area chart instead of a line chart
• since, until: time.ParseDuration to set distance in the past to start charting from or until
• width, height: adjust chart dimensions in inches
• step: number of seconds between data points
• min, max: Y axis limits
• label: template for the chart legend in Go's text/template format. All values provided by prometheus as tags are available - to label each matching result by the instance, for instance, use {{.instance}}