Kubernetes

Introduction

The Kubernetes agent monitors your Kubernetes cluster using an easy to deploy pod in your cluster.

Prerequisites

• A valid Kubernetes token.
• An InfraSonar asset ID if you want to use a Deployment instead of a StatefulSet.

Installation

Create a namespace for the agent:

namespace.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: monitoring

Create a cluster role for the agent:

cluster_role.yaml

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: infrasonar
rules:
- apiGroups: ["metrics.k8s.io", "apiregistration.k8s.io", ""]
  resources: ["pods", "namespaces", "nodes", "nodes/proxy", "apiservices", "persistentvolumeclaims", "services"]
  verbs: ["list", "get"]

Create a cluster role binding for the agent:

cluster_role_binding.yaml

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: infrasonar
subjects:
- kind: ServiceAccount
  name: default
  namespace: monitoring
roleRef:
  kind: ClusterRole
  name: infrasonar
  apiGroup: rbac.authorization.k8s.io

Apply the above files:

kubectl apply -f namespace.yaml
kubectl apply -f cluster_role.yaml
kubectl apply -f cluster_role_binding.yaml

Deployment

Choose your desired deployment

If you already have an asset or want to create one manually in InfraSonar, you only need the asset ID and can use a Deployment. Otherwise, skip this part and read the StatefulSet section.

Create a deployment for the agent:

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: infrasonar
  namespace: monitoring
  labels:
    app: infrasonar
spec:
  selector:
    matchLabels:
      app: infrasonar
  template:
    metadata:
      labels:
        app: infrasonar
    spec:
      containers:
      - name: infrasonar
        image: ghcr.io/infrasonar/kubernetes-agent:latest
        imagePullPolicy: Always
        env:
        - name: ASSET_ID
          value: "<REPLACE_WITH_YOUR_ASSET_ID>"
        - name: TOKEN
          value: "<REPLACE_WITH_YOUR_AGENT_TOKEN>"

Apply the deployment:

kubectl apply -f deployment.yaml

StatefulSet

Use a StatefulSet only if you want the agent to create the asset for you, otherwise use a Deployment.

Create a StatefulSet for the agent:

stateful_set.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: infrasonar
  namespace: monitoring
  labels:
    app: infrasonar
spec:
  selector:
    matchLabels:
      app: infrasonar
  serviceName: infrasonar
  replicas: 1
  template:
    metadata:
      labels:
        app: infrasonar
    spec:
      containers:
      - name: infrasonar
        image: ghcr.io/infrasonar/kubernetes-agent:latest
        imagePullPolicy: Always
        env:
        - name: ASSET_ID
          value: "/mnt/data/asset.json"
        - name: TOKEN
          value: "<REPLACE_WITH_YOUR_AGENT_TOKEN>"
        volumeMounts:
        - name: data
          mountPath: /mnt/data
  volumeClaimTemplates:
  - metadata:
      name: data
    spec:
      accessModes: ["ReadWriteOnce"]
      resources:
        requests:
          storage: 1Mi

Apply the StatefulSet:

kubectl apply -f stateful_set.yaml

Cleanup

When you no longer want to use the Kubernetes agent, you can remove it with the following steps:

If a Deployment was used:

kubectl delete deployment infrasonar --namespace=monitoring

If a StatefulSet was used:

kubectl delete sts infrasonar --namespace=monitoring
kubectl delete pvc -l app.kubernetes.io/name=infrasonar --namespace=monitoring

Cleanup the namespace, service account and associated role and binding:

kubectl delete ClusterRoleBinding infrasonar
kubectl delete ClusterRole infrasonar
kubectl delete ns monitoring

My CPU and Memory metrics are missing

If the pod and node CPU and Memory metrics are missing, please check the agent logging. Most likely the metric server is not running. This can be checked using the following command:

kubectl get apiservices v1beta1.metrics.k8s.io

The above should return with something like:

NAME                     SERVICE                      AVAILABLE   AGE
v1beta1.metrics.k8s.io   kube-system/metrics-server   True        123d

Click here for information on how to install the metrics server.

Additional information

Kubernetes agent source code