The Datadog Operator is a way to deploy the Datadog Agent on Kubernetes and OpenShift. It reports deployment status, health, and errors in its Custom Resource status, and it limits the risk of misconfiguration thanks to higher-level configuration options.

Prerequisites

Using the Datadog Operator requires the following prerequisites:

• Kubernetes Cluster version >= v1.20.X: Tests were done on versions >= 1.20.0. Still, it should work on versions >= v1.11.0. For earlier versions, because of limited CRD support, the Operator may not work as expected.
• Helm for deploying the datadog-operator.
• Kubectl CLI for installing the datadog-agent.

Deploy the Datadog Operator

To facilitate the command execution, define an environment variable called DD_NAMESPACE in your shell. To use the Datadog Operator, deploy it in your Kubernetes cluster. Then create a DatadogAgent Kubernetes resource that contains the Datadog deployment configuration:

1. Add the Datadog Helm repo:

helm repo add datadog https://helm.datadoghq.com

2. Install the Datadog Operator:

helm install my-datadog-operator datadog/datadog-operator -n $DD_NAMESPACE

Deploy the Datadog Agents with the Operator

After deploying the Datadog Operator, create the DatadogAgent resource that triggers the Datadog Agent’s deployment in your Kubernetes cluster. By creating this resource in the Datadog-Operator namespace, the Agent is deployed as a DaemonSet on every Node of your cluster.

Create the datadog-agent.yaml manifest out of one of the following templates:

• Manifest with Logs, APM, process, and metrics collection enabled.
• Manifest with Logs, APM, and metrics collection enabled.
• Manifest with APM and metrics collection enabled.
• Manifest with Cluster Agent.
• Manifest with tolerations.

Replace <DATADOG_API_KEY> and <DATADOG_APP_KEY> with your Datadog API and application keys, then trigger the Agent installation with the following command:

$ kubectl apply -n $DD_NAMESPACE -f datadog-agent.yaml
datadogagent.datadoghq.com/datadog created

You can check the state of the DatadogAgent resource with:

kubectl get -n $DD_NAMESPACE dd datadog

NAME            ACTIVE   AGENT             CLUSTER-AGENT   CLUSTER-CHECKS-RUNNER   AGE
datadog-agent   True     Running (2/2/2)                                           110m

In a 2-worker-nodes cluster, you should see the Agent pods created on each node.

$ kubectl get -n $DD_NAMESPACE daemonset
NAME            DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE
datadog-agent   2         2         2       2            2           <none>          5m30s

$ kubectl get -n $DD_NAMESPACE pod -owide
NAME                                         READY   STATUS    RESTARTS   AGE     IP            NODE
agent-datadog-operator-d897fc9b-7wbsf        1/1     Running   0          1h      10.244.2.11   kind-worker
datadog-agent-k26tp                          1/1     Running   0          5m59s   10.244.2.13   kind-worker
datadog-agent-zcxx7                          1/1     Running   0          5m59s   10.244.1.7    kind-worker2

Cleanup

The following command deletes all the Kubernetes resources created by the above instructions:

kubectl delete datadogagent datadog
helm delete my-datadog-operator -n $DD_NAMESPACE

It is important to delete the DatadogAgent resource and let Operator perform a cleanup. When the DatadogAgent resource is created in a cluster, Operator adds a finalizer to prevent deletion until it finishes the cleanup of resources it created. If Operator is uninstalled first, attempts to delete the DatadogAgent resource are blocked indefinitely; this will block namespace deletion as well. A workaround in this situation is to remove the metadata.finalizers value from DatadogAgent resource.

Tolerations

Update your datadog-agent.yaml file with the following configuration to add the toleration in the Daemonset.spec.template of your DaemonSet :

kind: DatadogAgent
apiVersion: datadoghq.com/v2alpha1
metadata:
  name: datadog
spec:
  global:
    credentials:
      apiKey: <DATADOG_API_KEY>
      appKey: <DATADOG_APP_KEY>
  override:
    nodeAgent:
      image:
        name: gcr.io/datadoghq/agent:latest
      tolerations:
        - operator: Exists

Apply this new configuration:

$ kubectl apply -f datadog-agent.yaml
datadogagent.datadoghq.com/datadog updated

The DaemonSet update can be validated by looking at the new desired pod value:

$ kubectl get -n $DD_NAMESPACE daemonset
NAME            DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE
datadog-agent   3         3         3       3            3           <none>          7m31s

$ kubectl get -n $DD_NAMESPACE pod
NAME                                         READY   STATUS     RESTARTS   AGE
agent-datadog-operator-d897fc9b-7wbsf        1/1     Running    0          15h
datadog-agent-5ctrq                          1/1     Running    0          7m43s
datadog-agent-lkfqt                          0/1     Running    0          15s
datadog-agent-zvdbw                          1/1     Running    0          8m1s

Further Reading

Documentation, liens et articles supplémentaires utiles:

Datadog and KubernetesDOCUMENTATION