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Monitor Kubernetes

Monitoring the state of the database is crucial to timely identify and react to performance issues. Percona Monitoring and Management (PMM) solution enables you to do just that.

However, the database state also depends on the state of the Kubernetes cluster itself. Hence it’s important to have metrics that can depict the state of the Kubernetes cluster.

This document describes how to set up monitoring of the Kubernetes cluster health. This setup has been tested with the PMM server as the centralized data storage and the Victoria Metrics Kubernetes monitoring stack as the metrics collector. These steps may also apply if you use another Prometheus-compatible storage.

Pre-requisites

To set up monitoring of Kubernetes, you need the following:

  1. PMM Server up and running. You can run PMM Server as a Docker image, a virtual appliance, or on an AWS instance. Please refer to the official PMM documentation for the installation instructions.

  2. Helm v3 .

  3. kubectl .

  4. The PMM Server API key. The key must have the role “Admin”.

    Get the PMM API key:

    Generate the PMM API key

    You can query your PMM Server installation for the API Key using curl and jq utilities. Replace <login>:<password>@<server_host> placeholders with your real PMM Server login, password, and hostname in the following command:

    $ API_KEY=$(curl --insecure -X POST -H "Content-Type: application/json" -d {"name":"operator", "role": "Admin"}' "https://<login>:<password>@<server_host>/graph/api/auth/keys" | jq .key)

    Note

    The API key is not rotated.

Install the Victoria Metrics Kubernetes monitoring stack

Quick install

  1. To install the Victoria Metrics Kubernetes monitoring stack with the default parameters, use the quick install command. Replace the following placeholders with your values:

    • API-KEY - The API key of your PMM Server
    • PMM-SERVER-URL - The URL to access the PMM Server

    • UNIQUE-K8s-CLUSTER-IDENTIFIER - Identifier for the Kubernetes cluster. It can be the name you defined during the cluster creation.

      You should use a unique identifier for each Kubernetes cluster. The use of the same identifer for more than one Kubernetes cluster will result in the conflicts during the metrics collection.

    • NAMESPACE - The namespace where the Victoria metrics Kubernetes stack will be installed. If you haven’t created the namespace before, it will be created during the command execution.

      We recommend to use a separate namespace like monitoring-system.

      $ curl -fsL  https://raw.githubusercontent.com/Percona-Lab/k8s-monitoring/main/vm-operator-k8s-stack/quick-install.sh | bash -s -- --api-key <API-KEY> --pmm-server-url <PMM-SERVER-URL> --k8s-cluster-id <UNIQUE-K8s-CLUSTER-IDENTIFIER> --namespace <NAMESPACE>

    Note

    The Prometheus node exporter is not installed by default since it requires privileged containers with the access to the host file system. If you need the metrics for Nodes, add the --node-exporter-enabled flag as follows: 

    $ curl -fsL  https://raw.githubusercontent.com/Percona-Lab/k8s-monitoring/main/vm-operator-k8s-stack/quick-install.sh | bash -s -- --api-key <API-KEY> --pmm-server-url <PMM-SERVER-URL> --k8s-cluster-id <UNIQUE-K8s-CLUSTER-IDENTIFIER> --namespace <NAMESPACE> --node-exporter-enabled

Install manually

You may need to customize the default parameters of the Victoria metrics Kubernetes stack.

  • Since we use the PMM Server for monitoring, there is no need to store the data in Victoria Metrics Operator. Therefore, the Victoria Metrics Helm chart is installed with the vmsingle.enabled and vmcluster.enabled parameters set to false in this setup.
  • Check all the role-based access control (RBAC) rules of the victoria-metrics-k8s-stack chart and the dependencies chart, and modify them based on your requirements.

Configure authentication in PMM

To access the PMM Server resources and perform actions on the server, configure authentication.

  1. Encode the PMM Server API key with base64.

    $ echo -n <API-key> | base64 --wrap=0

    $ echo -n <API-key> | base64

  2. Create the Namespace where you want to set up monitoring. The following command creates the Namespace monitoring-system. You can specify a different name. In the latter steps, specify your namespace instead of the <namespace> placeholder.

    $ kubectl create namespace monitoring-system

  3. Create the YAML file for the Kubernetes Secrets and specify the base64-encoded API key value within. Let’s name this file pmm-api-vmoperator.yaml.

    pmm-api-vmoperator.yaml
    apiVersion: v1
data:
  api_key: <base-64-encoded-API-key>
kind: Secret
metadata:
  name: pmm-token-vmoperator
  #namespace: default
type: Opaque

  4. Create the Secrets object using the YAML file you created previously. Replace the <filename> placeholder with your value.

    $ kubectl apply -f pmm-api-vmoperator.yaml -n <namespace>

  5. Check that the secret is created. The following command checks the secret for the resource named pmm-token-vmoperator (as defined in the metadata.name option in the secrets file). If you defined another resource name, specify your value.

$ kubectl get secret pmm-token-vmoperator -n <namespace>

Create a ConfigMap to mount for kube-state-metrics

The kube-state-metrics (KSM) is a simple service that listens to the Kubernetes API server and generates metrics about the state of various objects - Pods, Deployments, Services and Custom Resources.

To define what metrics the kube-state-metrics should capture, create the ConfigMap and mount it to a container.

Use the example configmap.yaml configuration file to create the ConfigMap.

$ kubectl apply -f https://raw.githubusercontent.com/Percona-Lab/k8s-monitoring/main/vm-operator-k8s-stack/ksm-configmap.yaml -n <namespace>

As a result, you have the customresource-config-ksm ConfigMap created.

Install the Victoria Metrics Kubernetes monitoring stack

  1. Add the dependency repositories of victoria-metrics-k8s-stack chart.

    $ helm repo add grafana https://grafana.github.io/helm-charts
$ helm repo add prometheus-community https://prometheus-community.github.io/helm-charts

  2. Add the Victoria Metrics Kubernetes monitoring stack repository.

    $ helm repo add vm https://victoriametrics.github.io/helm-charts/

  3. Update the repositories.

    $ helm repo update

  4. Install the Victoria Metrics Kubernetes monitoring stack Helm chart. You need to specify the following configuration:

    • the URL to access the PMM server in the externalVM.write.url option in the format <PMM-SERVER-URL>/victoriametrics/api/v1/write. The URL can contain either the IP address or the hostname of the PMM server.
    • the unique name or an ID of the Kubernetes cluster in the vmagent.spec.externalLabels.k8s_cluster_id option. Ensure to set different values if you are sending metrics from multiple Kubernetes clusters to the same PMM Server.
    • the <namespace> placeholder with your value. The Namespace must be the same as the Namespace for the Secret and ConfigMap.
    $ helm install vm-k8s vm/victoria-metrics-k8s-stack \
-f https://raw.githubusercontent.com/Percona-Lab/k8s-monitoring/main/vm-operator-k8s-stack/values.yaml \
--set externalVM.write.url=<PMM-SERVER-URL>/victoriametrics/api/v1/write \
--set vmagent.spec.externalLabels.k8s_cluster_id=<UNIQUE-CLUSTER-IDENTIFER/NAME> \
-n <namespace>

    To illustrate, say your PMM Server URL is https://pmm-example.com, the cluster ID is test-cluster and the Namespace is monitoring-system. Then the command would look like this:

    $ helm install vm-k8s vm/victoria-metrics-k8s-stack \
-f https://raw.githubusercontent.com/Percona-Lab/k8s-monitoring/main/vm-operator-k8s-stack/values.yaml \
--set externalVM.write.url=https://pmm-example.com/victoriametrics/api/v1/write \
--set vmagent.spec.externalLabels.k8s_cluster_id=test-cluster \
-n monitoring-system

Validate the successful installation

$ kubectl get pods -n <namespace>
Sample output 
vm-k8s-stack-kube-state-metrics-d9d85978d-9pzbs                   1/1     Running   0          28m
vm-k8s-stack-victoria-metrics-operator-844d558455-gvg4n           1/1     Running   0          28m
vmagent-vm-k8s-stack-victoria-metrics-k8s-stack-55fd8fc4fbcxwhx   2/2     Running   0          28m

What Pods are running depends on the configuration chosen in values used while installing victoria-metrics-k8s-stack chart.

Verify metrics capture

  1. Connect to the PMM server.
  2. Click Explore and switch to the Code mode.

  3. Check that the required metrics are captured, type the following in the Metrics browser dropdown:

    image

    • kubelet:

    image

    • kube-state-metrics metrics that also include Custom resource metrics for the Operator and database deployed in your Kubernetes cluster:

    image

Uninstall Victoria metrics Kubernetes stack

To remove Victoria metrics Kubernetes stack used for Kubernetes cluster monitoring, use the cleanup script. By default, the script removes all the Custom Resource Definitions(CRD) and Secrets associated with the Victoria metrics Kubernetes stack. To keep the CRDs, run the script with the --keep-crd flag.

Replace the <NAMESPACE> placeholder with the namespace you specified during the Victoria metrics Kubernetes stack installation: 

$ bash <(curl -fsL https://raw.githubusercontent.com/Percona-Lab/k8s-monitoring/main/vm-operator-k8s-stack/cleanup.sh) --namespace <NAMESPACE>

Replace the <NAMESPACE> placeholder with the namespace you specified during the Victoria metrics Kubernetes stack installation: 

$ bash <(curl -fsL https://raw.githubusercontent.com/Percona-Lab/k8s-monitoring/main/vm-operator-k8s-stack/cleanup.sh) --namespace <NAMESPACE> --keep-crd

Check that the Victoria metrics Kubernetes stack is deleted:

$ helm list -n <namespace>

The output should provide the empty list.

If you face any issues with the removal, uninstall the stack manually:

$ helm uninstall vm-k8s-stack -n < namespace>

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Last update: 2024-09-15