The COS Lite bundle is a Juju-based observability stack consisting of Prometheus, Loki, Alertmanager and Grafana.
This tutorial assumes you have a JuJu controller bootstrapped on a MicroK8s cloud that is ready to use. A typical setup using snaps can be found in the Juju docs. Follow the instructions there to install Juju and MicroK8s.
Let’s go and deploy that bundle!
Before deploying anything you must have a Juju model. It is usually a good idea to create a dedicated model for the COS Lite bundle. So let’s do just that and call the new model cos:
juju add-model cos
juju switch cos
Next, deploy the bundle with:
juju deploy cos-lite \
--channel=edge \
--trust
Now you can sit back and watch the deployment take place:
juju status \
--relations \
--color \
--watch 2s
The status of your deployment should eventually be very similar to the following:
> juju status --relations
Model Controller Cloud/Region Version SLA Timestamp
cos cos-uk8s microk8s/localhost 2.9.15 unsupported 16:53:38-00:00
App Version Status Scale Charm Store Channel Rev OS Address Message
alertmanager active 1 alertmanager-k8s charmhub edge 6 kubernetes 10.152.183.175
grafana active 1 grafana-k8s charmhub edge 10 kubernetes 10.152.183.156
loki active 1 loki-k8s charmhub edge 6 kubernetes 10.152.183.6
prometheus active 1 prometheus-k8s charmhub edge 10 kubernetes 10.152.183.227
Unit Workload Agent Address Ports Message
alertmanager/0* active idle 10.1.24.70
grafana/0* active idle 10.1.24.71
loki/0* active idle 10.1.24.82
prometheus/0* active idle 10.1.24.73
Relation provider Requirer Interface Type Message
alertmanager:alerting prometheus:alertmanager alertmanager_dispatch regular
alertmanager:replicas alertmanager:replicas alertmanager_replica peer
grafana:grafana-peers grafana:grafana-peers grafana_peers peer
loki:grafana-source grafana:grafana-source grafana_datasource regular
prometheus:grafana-source grafana:grafana-source grafana_datasource regular
Now COS Lite is good to go: you can relate software with it to begin the monitoring!
Alternatively, you may want to deploy the bundle with one or more of our readily available overlays, which is what we’ll cover next.
An overlay is a set of model-specific modifications that avoid repetitive overhead in setting up bundles like COS Lite.
Specifically, we offer the following overlays:
the offers overlay makes your COS model ready for cross-model relations
the storage-small overlay applies some defaults for the various storages used by the COS Lite components.
You can apply the offers overlay do an existing COS Lite bundle by executing the juju deploy command.
The storage-small overlay, however, is applicable only on the first deployment.
So, if you were following the previous steps you would first need to switch to a new Juju model or remove all applications from the current one.
To use any of the overlays above, you need to include an --overlay argument per overlay (applied in order):
curl -L https://raw.githubusercontent.com/canonical/cos-lite-bundle/main/overlays/offers-overlay.yaml -O
curl -L https://raw.githubusercontent.com/canonical/cos-lite-bundle/main/overlays/storage-small-overlay.yaml -O
juju deploy cos-lite \
--trust \
--channel=edge \
--overlay ./offers-overlay.yaml \
--overlay ./storage-small-overlay.yaml
When all the charms are deployed you can head over to browse their built-in web-UIs. You can find out their addresses from juju status, which should have a section similar to:
Unit Workload Agent Address Ports Message
alertmanager/0* active idle 10.1.24.70
grafana/0* active idle 10.1.24.71
loki/0* active idle 10.1.24.82
prometheus/0* active idle 10.1.24.73
In this case, the dashboards would be something like:
http://10.1.24.70:9093, for alertmanagerhttp://10.1.24.71:3000, for grafanahttp://10.1.24.73:9090, for prometheus(Note: the IP addresses are almost certainly going to be different in your case.)
Enjoy!
Congrats, you made it! You should now be able to easily:
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