This summary provides an overview of a blog post discussing how to set up a custom metric using Flex, a tool for ingesting and visualizing data in New Relic, with Ookla's Speedtest utility as the data source. The post explains that Flex can automatically ingest JSON data from external tools like Speedtest, making it easy to collect and visualize metrics such as download speed and latency. The author provides a YAML configuration file to set up the integration, including a timeout of 5 minutes and an interval of 1 hour between tests. The post also discusses how to remove unnecessary keys in the JSON data and post-process the data to get the desired metric values. Finally, it provides instructions on how to ingest the custom data into New Relic and visualize it on a dashboard. The author invites readers to join a discussion on Reddit and provides links to further resources and documentation.