Use DigitalOcean's Public API to fetch metrics for tagged droplets, using curl and jq:
TAG_NAME="wibble" DIGITALOCEAN_TOKEN="[REDACTED]" ./metrics.sh
Serve fetched metrics using a local http server (Caddy), rendered into graphs using Highcharts:
./serve.sh
View your collected metrics at http://localhost:3000/
Tip
If you would like to avoid fetching metrics with curl and jq you may be interested in the nocache branch that uses Caddy server's reverse-proxy capabilities to fetch metrics directly from DigitalOcean's Public API.