Install a Kubernetes Delegate

Updated 4 days ago by Michael Cretzman

The Harness Delegate is a service you run in your own environment, such as your local network, VPC, or cluster.

For example, you can run the Delegate in the deployment target cluster for a CD Pipeline or the build farm cluster for a CI Pipeline.

The Delegate connects all of your artifact, infrastructure, collaboration, verification, and other providers with the Harness Manager.

Most importantly, the Delegate performs all Harness operations.

There are several types of Delegates. This topic describes how to install the Kubernetes Delegate.

If you are migrating from Harness FirstGen to Harness NextGen, you must install new Delegates in Harness NextGen. Harness FirstGen Delegates won't work with Harness NextGen.

In this topic:

Before You Begin

Limitations

Currently, Harness Kubernetes Delegates don't install with the default settings in GKE Auto Pilot Mode. Please use the Manual mode when creating the cluster to make sure it meets the Delegate requirements.

Visual Summary

The following diagram shows how the Delegate enables Harness to integrate with all of your deployment resources:

Here's a 10min video that walks you through adding a Harness Kubernetes Cluster Connector and Harness Kubernetes Delegate. The Delegate is added to the target cluster and then the Kubernetes Cluster Connector uses the Delegate to connect to the cluster:

Review: Inline and Standalone Installation

You can install a Delegate whenever you are adding a Connector to a Pipeline or you can install one outside a Pipeline in Resources.

The steps involved are the same.

Review: Where Can I Install the Kubernetes Delegate?

You can install the Kubernetes Delegate inside or outside your deployment target cluster (CD) or build farm cluster (CIE).

  • Inside the cluster: you can install the Kubernetes Delegate inside the target or build farm cluster. Later, when you add a Kubernetes Cluster Connector, the Connector can inherit its credentials from the Kubernetes Delegate.
  • Outside the cluster: you can install the Kubernetes Delegate outside the target or build farm cluster. Later, when you add a Kubernetes Cluster Connector, the Connector cannot inherit its credentials from the Kubernetes Delegate. In this case, the Kubernetes Cluster Connector must use an alternate method for credentials. For example, the master URL of the target cluster and a Service Account with the required credentials.

Step 1: Ensure Kubernetes Prerequisites

To install a Kubernetes Delegate, you must have access to a Kubernetes cluster. You'll install the Harness Delegate as YAML or Helm Chart.

For connectivity, see Delegate Requirements and Limitations.

You'll need the following Kubernetes permissions to install the delegate:

  • Permission to create a namespace (for the Harness Delegate namespace).
  • Permission to create statefulSets (to create the Harness Delegate pod).

Step 2: Select the Kubernetes Delegate Type

Inline or standalone, click New Delegate.

Delegate selection options appear.

Click Kubernetes, and then click Continue.

Enter a name and description for the Delegate that will let others know what it is used for, or where it's installed.

Step 3: Select Delegate Size

In Delegate Size, select the size of Delegate you want to install.

Your Kubernetes cluster must have the unallocated resources required to run the Harness Delegate workload:

  • Laptop - 1.6GB memory, 0.5CPU
  • Small - 3.3GB memory, 1CPU
  • Medium - 6.6GB memory, 2CPU
  • Large - 13.2GB memory, 4CPU
Important: these sizing requirements are for the Delegate only. Your cluster will require more memory for Kubernetes, the operating system, and other services.

Important Resource Considerations

These requirements are for the Delegate only. Your cluster will have system, Kubernetes, and other resources consumers. Make sure that the cluster has enough memory, storage, and CPU for all of its resource consumers.

Most importantly, when the Delegate is installed inside the target deployment or build farm cluster, the cluster must also support the resources needed by the services you are deploying or building.

For example, if you use the Small option that requires 3.3GB of memory, don't use a cluster with only 4GB or memory. It won't be enough to run the Delegate and other resources.

Step 4: Delegate Configuration

Delegate Configurations include installation scripts you want to run on the Delegate host, tags, and other settings.

Select a Delegate Configuration. The default is Primary.

Click Continue.

Step 5: Download and Install the Script

Click Download Script. The YAML file for the Kubernetes Delegate, and its README, will download to your computer as an archive.

Open a terminal and navigate to where the Delegate file is located.

Extract the YAML file's folder from the download and then navigate to the harness-delegate-kubernetes folder that you extracted:

tar -zxvf harness-delegate-kubernetes.tar.gz

cd harness-delegate-kubernetes

You'll connect to your cluster using the terminal so you can simply copy the YAML file over.

In the same terminal, log into your Kubernetes cluster. In most platforms, you select the cluster, click Connect, and copy the access command.

Let's quickly confirm that the cluster you created can connect to the Harness platform. Enter the following command:

Next, install the Harness Delegate using the harness-delegate.yaml file you just downloaded. In the terminal connected to your cluster, run this command:

kubectl apply -f harness-delegate.yaml

The successful output is something like this:

% kubectl apply -f harness-delegate.yaml
namespace/harness-delegate unchanged
clusterrolebinding.rbac.authorization.k8s.io/harness-delegate-cluster-admin unchanged
secret/k8s-quickstart-proxy unchanged
statefulset.apps/k8s-quickstart-sngxpn created
service/delegate-service unchanged

Run this command to verify that the Delegate pod was created:

kubectl get pods -n harness-delegate

It'll take a moment for the Delegate to appear in Harness' Delegates list.

You're ready to connect Harness to your artifact server and cluster. After those quick steps, you'll begin creating your deployment.

Step 6: Verify

Click Verify and Harness will verify that it is receiving heartbeats from the Delegate.

Your Delegate is installed.

Option: Troubleshooting

Harness will provide a lot of troubleshooting steps. Here are a few:

Check the status of the Delegate on your cluster:

kubectl describe pod <your-delegate-pod> -n harness-delegate

Check the Delegate logs:

kubectl logs -f <harness-delegate> -n harness-delegate

If the pod isn't up, you might see the following error in your cluster:

CrashLoopBackOff: Kubernetes Cluster Resources are not available.

Make sure the Kubernetes Cluster Resources (CPU, Memory) are enough.

If the Delegate didn’t reach a healthy state, try this:

kubectl describe pod <your-delegate-pod> -n harness-delegate

See Also

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