COS Lite

Canonical Observability Stack Lite (COS Lite) is designed for the Edge and is capable of running reliably alongside MicroK8s and Juju with limited computing resources (around 8 GB of memory).

The charms in COS Lite can be integrated with other Juju-managed applications to provide a turn-key observability solution for your charmed workloads. You can however also use the Grafana Agent to set up COS Lite to monitor your applications even if they’re not charmed: see how.


The charmed operators that make up COS are available as the pre-configured COS Lite bundle. COS Lite is made up of the following Juju charmed operators:

Additionally, there are charmed operators designed to work with COS to provide additional functionality:

  • The Prometheus Scrape Config charmed operator allows you to ** tweak the settings of the scrape jobs** when relating a charm to the Prometheus charmed operator.

  • The Prometheus Scrape Target charmed operator allows you to represent /metrics endpoints provided by software not managed by Juju, e.g., LXD or MaaS, so that the Prometheus charmed operator can scrape metrics from them.

  • The COS Proxy charmed operator is a machine charm designed to “translate” the relations supported by the previous iteration, LMA, to COS.

  • The COS Configuration charmed operator provides a GitOps approach to manage Prometheus alerts, Loki alerts and Grafana dashboards that are specific to your Juju deployments, rather than any particular charm.

  • The Karma charmed operator runs the Karma UI for you on kubernetes, which enables you to visualize alerts from various Alertmanager clusters, e.g., when you were to deploy many different COS on Edge computing on in different production environments, and wanted to keep a centralized overview.

  • The Grafana Agent charmed operator provides a way to fetch and forward telemetry and dashboards via cross-model relations and from remote workloads, and send them over to the observability stack.

Last updated 8 months ago.