Observability Overview

This document attempts to explain how the different components in Open Cluster Management Observabilty come together to deliver multicluster fleet observability. We do leverage several open source projects: Grafana, Alertmanager, Thanos, Observatorium Operator and API Gateway, Prometheus; We also leverage a few Open Cluster Mangement projects namely - Cluster Manager or Registration Operator, Klusterlet. The multicluster-observability operator is the root operator which pulls in all things needed.

Conceptual Diagram

Associated Github Repositories

Component	Git Repo	Description
MCO Operator	multicluster-observability-operator	Operator for monitoring. This is the root repo. If we follow the Readme instructions here to install, the code from all other repos mentioned below are used/referenced.
Endpoint Operator	endpoint-metrics-operator	Operator that manages setting up observability and data collection at the managed clusters.
Observatorium Operator	observatorium-operator	Operator to deploy the Observatorium project. Inside the open cluster management, at this time, it means metrics using Thanos. Forked from main observatorium-operator repo.
Metrics collector	metrics-collector	Scrapes metrics from Prometheus at managed clusters, the metric collection being shaped by configuring allow-list.
RBAC Proxy	rbac_query_proxy	Helper service that acts a multicluster metrics RBAC proxy.
Grafana	grafana	Grafana repo - for dashboarding and metric analytics. Forked from main grafana repo.
Dashboard Loader	grafana-dashboard-loader	Sidecar proxy to load grafana dashboards from configmaps.
Management Ingress	management-ingress	NGINX based ingress controller to serve Open Cluster Management services.
Observatorium API	observatorium	API Gateway which controls reading, writing of the Observability data to the backend infrastructure. Forked from main observatorium API repo.
Thanos Ecosystem	kube-thanos	Kubernetes specific configuration for deploying Thanos. The observatorium operator leverages this configuration to deploy the backend Thanos components.

Quick Start Guide

Prerequisites

• Ensure kubectl and kustomize are installed.
• Prepare a OpenShift cluster to function as the hub cluster.
• Ensure docker 17.03+ is installed.
• Ensure golang 1.15+ is installed.
• Ensure operator-sdk 1.4.2+ in installed.
• Ensure the open-cluster-management cluster manager is installed. See Cluster Manager for more information.
• Ensure the open-cluster-management klusterlet is installed. See Klusterlet for more information.

Note: By default, the API conversion webhook use on the OpenShift service serving certificate feature to manage the certificate, you can replace it with cert-manager if you want to run the multicluster-observability-operator in a kubernetes cluster.

Use the following quick start commands for building and testing the multicluster-observability-operator:

Clone the Repository

Check out the multicluster-observability-operator repository.

git clone [email protected]:stolostron/multicluster-observability-operator.git
cd multicluster-observability-operator

Build the Operator

Build the multicluster-observability-operator image and push it to a public registry, such as quay.io:

make docker-build docker-push IMG=quay.io/<YOUR_USERNAME_IN_QUAY>/multicluster-observability-operator:latest

Run the Operator in the Cluster

1. Create the open-cluster-management-observability namespace if it doesn't exist:

kubectl create ns open-cluster-management-observability

2. Deploy the minio service which acts as storage service of the multicluster observability:

kubectl -n open-cluster-management-observability apply -k examples/minio

3. Replace the operator image and deploy the multicluster-observability-operator:

make deploy IMG=quay.io/<YOUR_USERNAME_IN_QUAY>/multicluster-observability-operator:latest

4. Deploy the multicluster-observability-operator CR:

kubectl apply -f operators/multiclusterobservability/config/samples/observability_v1beta2_multiclusterobservability.yaml

5. Verify all the components for the Multicluster Observability are starting up and running:

kubectl -n open-cluster-management-observability get pod
NAME                                                       READY   STATUS    RESTARTS   AGE
minio-79c7ff488d-72h65                                     1/1     Running   0          9m38s
observability-alertmanager-0                               3/3     Running   0          7m17s
observability-alertmanager-1                               3/3     Running   0          6m36s
observability-alertmanager-2                               3/3     Running   0          6m18s
observability-grafana-85fdc8c48d-j67j6                     2/2     Running   0          7m17s
observability-grafana-85fdc8c48d-wnltt                     2/2     Running   0          7m17s
observability-observatorium-api-69cfff4c95-bpw5s           1/1     Running   0          7m2s
observability-observatorium-api-69cfff4c95-gbh7b           1/1     Running   0          7m2s
observability-observatorium-operator-5df6b7949c-kbpmp      1/1     Running   0          7m17s
observability-rbac-query-proxy-d44df47c4-9ccdn             2/2     Running   0          7m15s
observability-rbac-query-proxy-d44df47c4-rtcgh             2/2     Running   0          6m50s
observability-thanos-compact-0                             1/1     Running   0          7m2s
observability-thanos-query-79c4d9488b-bd5sf                1/1     Running   0          7m3s
observability-thanos-query-79c4d9488b-d7wzt                1/1     Running   0          7m3s
observability-thanos-query-frontend-6fdb5d4946-rgblb       1/1     Running   0          7m3s
observability-thanos-query-frontend-6fdb5d4946-shsz2       1/1     Running   0          7m3s
observability-thanos-query-frontend-memcached-0            2/2     Running   0          7m3s
observability-thanos-query-frontend-memcached-1            2/2     Running   0          6m37s
observability-thanos-query-frontend-memcached-2            2/2     Running   0          6m33s
observability-thanos-receive-controller-6b446c5576-hj6xl   1/1     Running   0          7m3s
observability-thanos-receive-default-0                     1/1     Running   0          7m2s
observability-thanos-receive-default-1                     1/1     Running   0          6m20s
observability-thanos-receive-default-2                     1/1     Running   0          5m50s
observability-thanos-rule-0                                2/2     Running   0          7m3s
observability-thanos-rule-1                                2/2     Running   0          6m27s
observability-thanos-rule-2                                2/2     Running   0          5m56s
observability-thanos-store-memcached-0                     2/2     Running   0          7m3s
observability-thanos-store-memcached-1                     2/2     Running   0          6m37s
observability-thanos-store-memcached-2                     2/2     Running   0          6m33s
observability-thanos-store-shard-0-0                       1/1     Running   2          7m3s
observability-thanos-store-shard-1-0                       1/1     Running   2          7m3s
observability-thanos-store-shard-2-0                       1/1     Running   2          7m3s

What is next

After a successful deployment, you can run the following command to check if you have OCP cluster as a managed cluster.

kubectl get managedcluster --show-labels

If there is no vendor=OpenShift label exists in your managed cluster, you can manually add this label with this command kubectl label managedcluster <managed cluster name> vendor=OpenShift

Then you should be able to have metrics-collector pod is running:

kubectl -n open-cluster-management-addon-observability get pod
endpoint-observability-operator-5c95cb9df9-4cphg   1/1     Running   0          97m
metrics-collector-deployment-6c7c8f9447-brpjj      1/1     Running   0          96m

Expose the thanos query frontend via route by running this command:

cat << EOF | kubectl -n open-cluster-management-observability apply -f -
kind: Route
apiVersion: route.openshift.io/v1
metadata:
  name: query-frontend
spec:
  port:
    targetPort: http
  wildcardPolicy: None
  to:
    kind: Service
    name: observability-thanos-query-frontend
EOF

You can access the thanos query UI via browser by inputting the host from oc get route -n open-cluster-management-observability query-frontend. There should have metrics available when you search the metrics :node_memory_MemAvailable_bytes:sum. The available metrics are listed here

Uninstall the Operator in the Cluster

1. Delete the multicluster-observability-operator CR:

kubectl -n open-cluster-management-observability delete -f operators/multiclusterobservability/config/samples/observability_v1beta2_multiclusterobservability.yaml

2. Delete the multicluster-observability-operator:

make undeploy

3. Delete the minio service:

kubectl -n open-cluster-management-observability delete -k examples/minio

4. Delete the open-cluster-management-observability namespace:

kubectl delete ns open-cluster-management-observability

Rebuild Image: Wed Jan 25 15:08:26 EST 2023