Set up Kubernetes/OpenShift monitoring with DaemonSet

This page describes how you can set up OneAgent on Kubernetes using the OneAgent DaemonSet. DaemonSet is a feature that makes sure that if a copy of a pod on a node dies, the copy is recreated, and if nodes are added to the cluster, copies of the pod are added as well.
For a clear view of all the deployment strategies, see Deployment options on Kubernetes/OpenShift.

Prerequisites

Pods must allow egress to your Dynatrace environment or to your Environment ActiveGate in order for metric routing to work properly.
Locate the ONEAGENT_INSTALLER_SCRIPT_URL. This information is shared during Dynatrace OneAgent installation.

How to locate your installer URL

To get your ONEAGENT_INSTALLER_SCRIPT_URL

In the Dynatrace menu, go to Deploy Dynatrace.
Select Start installation, and then Linux.
Determine the installer script URL and token from the UI-provided wget command:

OneAgent container image version 1.39.1000+OneAgent container image version 1.38.1000 and earlier

This is the URL:

Replace the value of arch parameter with <arch>. Ignore the flavor=default parameter.
For the API-Token value, you need a PaaS token.

Your URL should look like this: https://host.domain.com/api/v1/deployment/installer/agent/unix/default/latest?arch=<arch>

This is your ONEAGENT_INSTALLER_SCRIPT_URL.

This your URL and API token.

Append the API token to the URL using the API-Token parameter. Your URL should look like this:

https://host.domain.com/api/v1/deployment/installer/agent/unix/default/latest?arch=x86&flavor=default&Api-Token=<token>

This is your ONEAGENT_INSTALLER_SCRIPT_URL.

Install DaemonSet

Download or copy the dynatrace-oneagent.yml Kubernetes template.

dynatrace-oneagent.yml

yml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: dynatrace-oneagent
spec:
  selector:
    matchLabels:
      name: dynatrace-oneagent
  template:
    metadata:
      labels:
        name: dynatrace-oneagent
    spec:
      hostPID: true
      hostIPC: true
      hostNetwork: true
      nodeSelector:
        beta.kubernetes.io/os: linux
      volumes:
        - name: host-root
          hostPath:
            path: /
      containers:
        - name: dynatrace-oneagent
          image: dynatrace/oneagent
          env:
            - name: ONEAGENT_INSTALLER_SCRIPT_URL
              value: your_URL
            - name: ONEAGENT_INSTALLER_SKIP_CERT_CHECK
              value: 'false'
            - name: ONEAGENT_INSTALLER_DOWNLOAD_TOKEN
              value: '<API-Token>'
          args:
            - '--set-network-zone=<your.network.zone>'
          volumeMounts:
            - name: host-root
              mountPath: /mnt/root
          securityContext:
            privileged: true

ONEAGENT_INSTALLER_DOWNLOAD_TOKEN is only needed for OneAgent container image versions 1.39+ and is ignored for earlier versions.
The --set-app-log-content-access parameter is passed to the OneAgent installer and, when set to true (or 1), allows OneAgent to access log files for the purpose of log monitoring. For more about this and other parameters, see Customize OneAgent installation on Linux.
You can configure network zones by setting the --set-network-zone=<your.network.zone> parameter. See network zones for more information.

Deploy Dynatrace OneAgent using the created file dynatrace-oneagent.yml.

kubectloc

bash
kubectl apply -f dynatrace-oneagent.yml --namespace=kube-system
daemonset "dynatrace-oneagent" created

bash
oc apply -f dynatrace-oneagent.yml --namespace=kube-system
daemonset "dynatrace-oneagent" created

Verify that the dynatrace-oneagent DaemonSet has deployed pods to the cluster nodes successfully:

kubectloc

bash
kubectl get pods --namespace=kube-system
NAME                       READY     STATUS              RESTARTS   AGE
dynatrace-oneagent-abcde   1/1       Running             0          1m

bash
oc get pods --namespace=kube-system
NAME                       READY     STATUS              RESTARTS   AGE
dynatrace-oneagent-abcde   1/1       Running             0          1m

kubectloc

bash
kubectl logs -f dynatrace-oneagent-abcde
09:46:18 Using volume-based storage
09:46:18 Started agent deployment as a Docker container, PID 1234.
09:46:18 Downloading agent to /tmp/Dynatrace-OneAgent-Linux.sh via https://EnvironmentID.live.dynatrace.com/api/v1/deployment/installer/agent/unix/default/latest?Api-Token=***&arch=x86&flavor=default
09:46:21 Download complete
09:46:21 Downloaded version: 1.x
09:46:21 Validating downloaded agent installer
09:46:23 Verification successful
...

bash
oc logs -f dynatrace-oneagent-abcde
09:46:18 Using volume-based storage
09:46:18 Started agent deployment as a Docker container, PID 1234.
09:46:18 Downloading agent to /tmp/Dynatrace-OneAgent-Linux.sh via https://EnvironmentID.live.dynatrace.com/api/v1/deployment/installer/agent/unix/default/latest?Api-Token=***&arch=x86&flavor=default
09:46:21 Download complete
09:46:21 Downloaded version: 1.x
09:46:21 Validating downloaded agent installer
09:46:23 Verification successful
...

Limitations

When you set up Kubernetes/OpenShift monitoring with DaemonSet, the shutdown state of the host is not detected. For details, see Host availability states.
See Docker limitations.

Connect your Kubernetes clusters to Dynatrace

Now that you have OneAgent running on your Kubernetes nodes, you're able to monitor those nodes and the applications running in Kubernetes. The next step is to connect the Kubernetes API to Dynatrace in order to get native Kubernetes metrics, like request limits, and differences in pods requested vs running pods.
For further instructions, see Connect your Kubernetes clusters to Dynatrace.

Update OneAgent DaemonSet

Whenever a new version of OneAgent becomes available in Dynatrace, you can redeploy OneAgent as explained in the steps below. The dynatrace-oneagent container will automatically fetch the latest version of Dynatrace OneAgent.

If you've specified a default OneAgent installation version for new hosts and applications in your OneAgent updates settings, the dynatrace-oneagent container will automatically fetch the defined default version of OneAgent.

Delete the dynatrace-oneagent DaemonSet.

kubectloc

bash
kubectl delete ds/dynatrace-oneagent

bash
oc delete ds/dynatrace-oneagent

Deploy Dynatrace OneAgent using the dynatrace-oneagent.yml DaemonSet file. Be sure to change the value REPLACE_WITH_YOUR_URL with the Dynatrace OneAgent installer URL.
kubectloc
```
bash
kubectl apply -f dynatrace-oneagent.yml --namespace=kube-system
```
```
bash
oc apply -f dynatrace-oneagent.yml --namespace=kube-system
```

Uninstall OneAgent DaemonSet

To uninstall OneAgent DaemonSet from Kubernetes versions 1.8 and earlier

Delete the dynatrace-oneagent DaemonSet.

kubectloc

bash
kubectl delete ds/dynatrace-oneagent

bash
oc delete ds/dynatrace-oneagent

optional After deleting the dynatrace-oneagent DaemonSet, the OneAgent binary remains on the node in an inactive state. To uninstall it completely, run the uninstall.sh script and delete logs and configuration files.
See Linux related information.