This Juju machine charm that provides a single integration point in the machine world with the Kubernetes-based COS bundle.
This charm is designed to be easy to integrate in bundles and Juju-driven appliances, and reduce the amount of setup needed to integrate with the Kubernetes-based COS to just connect the COS Proxy charm with it.
Proxying support is provided for:
- Prometheus
- Grafana Dashboards
- NRPE (through nrpe_exporter, which sends NRPE results to Prometheus)
The cos-proxy charm is used as a connector between a Juju model hosting applications on machines, and COS charms running within Kubernetes. In the following example our machine charms will be running on an OpenStack cloud, and the Kubernetes is Microk8s running on a separate host. There must be network connectivity from each of the endpoints to the Juju controller.
For example, we have two models. One, named 'reactive', hosting machine charms running on OpenStack. There is a Telegraf application, cs:telegraf, collecting metrics from units, and we wish to relate that to Prometheus and Grafana running in another model named cos, running Kubernetes.
If you already have a working COS Lite deployment, you can skip creating another one, as well as the steps where you would deploy the COS Lite components one by one.
Here's the steps to create the models:
$ juju clouds
Only clouds with registered credentials are shown.
There are more clouds, use --all to see them.
Clouds available on the controller:
Cloud Regions Default Type
microk8s-cluster 1 localhost k8s
serverstack 1 serverstack openstack
juju add-model reactive serverstack
juju add-model cos microk8s-cluster
Next we'll deploy an example application on the reactive model, which should be present
on a single Juju controller which manages both microk8s and a reactive model:
juju deploy -m cos prometheus-k8s
juju deploy -m cos grafana-k8s
juju deploy -m reactive cs:ubuntu --series focal -n 3
juju deploy -m reactive cs:telegraf
juju relate -m reactive telegraf:juju-info ubuntu:juju-info
To relate Telegraf to Prometheus in order to add scrape targets and alerting rules, we must use a cross model relation.
Offer the relation in the cos model:
juju offer microk8s-cluster:cos.prometheus-k8s:metrics-endpoint
Deploy the cos-proxy charm in a new machine unit on the target model:
juju deploy -m reactive cos-proxy # or ./cos-proxy_ubuntu-20.04-amd64.charm
juju relate -m reactive telegraf:prometheus-client cos-proxy:prometheus-target
juju relate -m reactive telegraf:prometheus-rules cos-proxy:prometheus-rules
Add the cross model relation:
juju consume -m reactive microk8s-cluster:cos.prometheus-k8s
juju relate -m reactive prometheus-k8s cos-proxy:downstream-prometheus-scrape
Now we can do the same for Grafana
juju offer microk8s-cluster:cos.grafana:grafana-dashboard
juju relate -m reactive telegraf:dashboards cos-proxy:dashboards
Add the cross model relation:
juju consume -m reactive microk8s-cluster:cos.prometheus-k8s
juju consume -m reactive microk8s-cluster:cos.grafana
juju relate -m reactive prometheus-k8s cos-proxy:downstream-prometheus-scrape
juju relate -m reactive grafana cos-proxy:downstream-grafana-dashboard
A complete set of relations on the from the consuming model will appear as:
Model Controller Cloud/Region Version SLA Timestamp
reactive overlord localhost/localhost 3.0.3 unsupported 20:40:45+01:00
SAAS Status Store URL
grafana active microk8s admin/cos.grafana
loki active microk8s admin/cos.loki
metrics active microk8s admin/cos.metrics
App Version Status Scale Charm Channel Rev Exposed Message
cos-proxy n/a active 1 cos-proxy edge 15 no
filebeat 6.8.23 active 1 filebeat stable 49 no Filebeat ready.
nrpe active 1 nrpe stable 97 no Ready
telegraf active 1 telegraf stable 65 no Monitoring ubuntu/0 (source version/commit 23.01)
ubuntu 20.04 active 1 ubuntu stable 21 no
Unit Workload Agent Machine Public address Ports Message
cos-proxy/0* active idle 1 10.218.235.237
ubuntu/0* active idle 0 10.218.235.198
filebeat/0* active idle 10.218.235.198 Filebeat ready.
nrpe/0* active idle 10.218.235.198 icmp,5666/tcp Ready
telegraf/0* active idle 10.218.235.198 9103/tcp Monitoring ubuntu/0 (source version/commit 23.01)
Machine State Address Inst id Series AZ Message
0 started 10.218.235.198 juju-732594-0 focal Running
1 started 10.218.235.237 juju-732594-1 focal Running
NRPE targets may appear on multiple relations. To capture all jobs, cos-proxy should be related to
BOTH an existing reactive NRPE subordinate charm, as well as the application which that charm is subordinated to,
as the monitors interface may appear on either, with the principal charm providing "host-level" checks, and
the subordinate nrpe providing application-level ones.
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