Legacy Kubernetes versions

The default configuration targets Kubernetes 1.7.6 and later, as the Agent relies on features and endpoints introduced in this version. More installation steps are required for older versions:

• RBAC objects (ClusterRoles and ClusterRoleBindings) are available since Kubernetes 1.6 and OpenShift 3.3, but are available under different apiVersion prefixes:

  • rbac.authorization.k8s.io/v1 in Kubernetes 1.8+ (and OpenShift 3.9+), the default apiVersion we target

  • rbac.authorization.k8s.io/v1beta1 in Kubernetes 1.5 to 1.7 (and OpenShift 3.7)

  • v1 in Openshift 3.3 to 3.6

    Apply the Datadog Agent yaml manifests with the following sed invocations:

    sed "s%authorization.k8s.io/v1%authorization.k8s.io/v1beta1%" clusterrole.yaml | kubectl apply -f -
    sed "s%authorization.k8s.io/v1%authorization.k8s.io/v1beta1%" clusterrolebinding.yaml | kubectl apply -f -
    

    or for Openshift 3.3 to 3.6:

    sed "s%rbac.authorization.k8s.io/v1%v1%" clusterrole.yaml | oc apply -f -
    sed "s%rbac.authorization.k8s.io/v1%v1%" clusterrolebinding.yaml | oc apply -f -
    

• The kubelet check retrieves metrics from the Kubernetes 1.7.6+ (OpenShift 3.7.0+) prometheus endpoint. Enable cAdvisor port mode for older versions.

• The default DaemonSet makes use of the downward API to pass the kubelet’s IP to the agent. This only works on versions 1.7 and up. For older versions, here are other ways to enable kubelet connectivity:

  • On version 1.6, use fieldPath: spec.nodeName and verify your node name is resolvable and reachable from the pod.
  • If DD_KUBERNETES_KUBELET_HOST is unset, the Agent retrieves the node hostname from docker and tries to connect there. See docker info | grep "Name:" and verify the name is resolvable and reachable.
  • If the IP of the docker default gateway is constant across your cluster, pass that IP in the DD_KUBERNETES_KUBELET_HOST envvar. You can retrieve the IP with the ip addr show | grep docker0 command.

• The default configuration relies on bearer token authentication to the API server and kubelet. On 1.3, the kubelet does not support bearer token auth, setup client certificates for the datadog-agent serviceaccount and pass them to the agent.

Further Reading

Additional helpful documentation, links, and articles:

Kubernetes DaemonSet SetupDOCUMENTATION Kubernetes Host SetupDOCUMENTATION Kubernetes MetricsDOCUMENTATION