Containerized, auto-scalable private Synthetic locations on Kubernetes

Dynatrace version 1.264+

Containerized, auto-scalable private Synthetic locations on Kubernetes and its commercial distribution OpenShift are an alternative to deploying Synthetic-enabled ActiveGates on separate hosts or virtual machines and then assigning them to private locations for the execution of synthetic monitors.

Unlike individual Synthetic-enabled ActiveGates that are deployed and assigned to private locations (and then tracked via utilization metrics) containerized locations are deployed as a whole, with a minimum and maximum number of ActiveGates as the necessary input parameters.

Kubernetes and OpenShift aren't just additional supported ActiveGate platforms along with Windows and Linux; with this offering, containerized private Synthetic locations:

You can execute scheduled as well as on-demand executions of all types of synthetic monitors on containerized locations.

You can manage Kubernetes/OpenShift locations via the Dynatrace web UI and the existing Synthetic - Locations, nodes, and configuration API v2. Additional Early Adopter endpoints in this API facilitate the deployment of Kubernetes locations; the new endpoints help you generate the commands that need to be executed on the Kubernetes cluster.

Architecture

Containerized private Synthetic locations are deployed as a whole.

Locations are scaled automatically by adjusting the number of ActiveGates per location by the following additional parts of the containerized location architecture.

Requirements

Containerized private Synthetic locations are supported with Dynatrace version 1.264+ on Kubernetes 1.22–1.25 with persistent volume and kubectl support.

Internet connectivity is required to access the public repositories where Docker images for the Synthetic-enabled ActiveGate and Synthetic metric adapter are available. These image locations are referenced in the respective template files—see Install a containerized location and Update a containerized location below.

The ActiveGate hardware requirements below are listed by size.

Best practices and caveats

ActiveGates

Locations

Synthetic metric adapter

Auto-scaling specifics

For auto-scaling purposes, the Synthetic metric adapter needs access to and extends the Kubernetes API by specifying a new API service—v1beta1.external.metrics.k8s.io.

This API service is defined in the Synthetic metric adapter template—see below.

apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:
  name: v1beta1.external.metrics.k8s.io
spec:
  service:
    name: dynatrace-metrics-apiserver
    namespace: {{adapterNamespace}}
  group: external.metrics.k8s.io
  version: v1beta1
  insecureSkipTLSVerify: true
  groupPriorityMinimum: 100
  versionPriority: 100

Note that any other metric adapter, such as a Prometheus adapter, in the Kubernetes cluster might also use this service.

The Synthetic metric adapter also modifies an existing resource in its template—the horizontal-pod-autoscaler ServiceAccount in kube-system namespace.

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: hpa-controller-dynatrace-metrics
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: dynatrace-metrics-server-resources
subjects:
  - kind: ServiceAccount
    name: horizontal-pod-autoscaler
    namespace: kube-system

Install a containerized location

Set up and manage a containerized location in the Dynatrace web UI at Settings > Web and Mobile monitoring > Private Synthetic locations.

Initial setup for a Kubernetes/OpenShift location

Deploy the location

Deploy the Synthetic metric adapter

Initial setup for a Kubernetes/OpenShift location

Your named location is displayed on the Private Synthetic locations page with the Kubernetes or OpenShift logo. Note that no ActiveGates are assigned to the location at this point.

Deploy the location

Select your location in Private Synthetic locations to download the location template and generate the commands that need to be executed on the Kubernetes cluster.

Deploy the Synthetic metric adapter

This procedure generates a separate template for the Synthetic metric adapter. You then execute generated commands on your Kubernetes cluster to deploy the metric adapter.

Update a containerized location or its ActiveGates

Any updates to a location require that you download the location template file again and apply the changes via kubectl.

To update ActiveGate versions

Any update redeploys ActiveGates in the reverse order of their deployment. For example, if your location contains the ActiveGates activegate-name-0 and activegate-name-1, activegate-name-1 is stopped and redeployed first.

The redeployed ActiveGate pod uses the same persistent volume deployed for log continuity.

Delete a location or metric adapter on Kubernetes

The commands generated when deploying a location and the Synthetic metric adapter also include code snippets for deleting them on Kubernetes. You may copy and store these commands for future reference.

At any point, you can regenerate the commands for the respective namespaces.

Location

Note that this procedure only deletes Kubernetes resources; it doesn't delete the location you initially set up in Dynatrace.

Synthetic metric adapter

Proxy configuration

Add the following code at the top of your location template file to insert a ConfigMap resource containing your proxy server information.

In the code sample below:

kind: ConfigMap
apiVersion: v1
data:
  custom.properties: |-
    [http.client]
    proxy-server = 10.102.43.210
    proxy-port = 3128
    proxy-user = proxyuser
    proxy-password = proxypass
metadata:
  name: ag-custom-configmap
  namespace: dynatrace
---

Add the following code at template.volumes.

- name: ag-custom-volume
          configMap:
            name: ag-custom-configmap
            items:
              - key: custom.properties
                path: custom.properties

Add the following code to the ActiveGate container configuration under volumeMounts:.

- name: ag-custom-volume
              mountPath: /var/lib/dynatrace/gateway/config_template/custom.properties
              subPath: custom.properties

Non-scalable containerized locations

Auto-scalable locations become non-scalable for any of the following reasons.

API: Synthetic - Locations, nodes, and configuration API v2

You can automate the deployment of and manage containerized locations via the existing Synthetic - Locations, nodes, and configuration API v2. Early Adopter endpoints added to this API to facilitate the deployment of Kubernetes locations. The new endpoints help generate the commands you need to execute on the Kubernetes cluster.