Observability Team Updates - Week #24 2022

Hi everyone! :wave:

Below you’ll find the updates from the Observability team for the week 24, starting 13th of June. For the last couple of weeks, we’ve been hard at work with getting the Prometheus charm up to the level needed to cut a release candidate. While we still have some way to go, we’re making steady progress in the right direction.

The team

The team consists of @leon-mintz, @bthomas, @dylanstathis, @jose, @rbarry, and yours truly. If you want to get in touch with any of us, we’re available either here or on the Charmhub Mattermost.

What is Prometheus?

Prometheus is an open-source monitoring and alerting tool, originally built by Soundcloud. Since it’s initial inception in 2012, it has quickly grown to become somewhat of an industry standard for monitoring, and alerting on, metric signals.

For us, Prometheus makes out a vital part of the COS Lite bundle, where it is responsible for scraping, ingesting, processing and supplying metric time series.

For more details on Prometheus in general, and the Prometheus charm in particular, see the charm listing on Charmhub and the official Prometheus docs.

When would I use it?

Whenever you are charming a workload that is generating metrics as part of its operations, or when you are adding your own instrumentation as part of the charm.


  • Replace promql-transform with cos-tool, adding logql transformation to the tool belt. (#297)
  • Add runtime validation of alert rules and alert rule expressions using cos-tool (#313, #315)
  • Automate integration testing for a whole monitoring chain (#310)
  • Automate integration testing for additional Juju relation lifecycle events (#259)
  • Resolve naming conflicts for duplicate scrape jobs coming in through different chains of relations (#292)

Have an excellent week! :tada: