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Online Installation with the Kubernetes Installer

This topic explains how to install an application on an embedded cluster provisioned by the Replicated Kubernetes installer.

The Kubernetes installer is based on the open source kURL project, which is maintained by Replicated. For more information about installing with kURL, including advanced installation options, see the kURL documentation.

About High Availability Mode​

Online installations can use high availability (HA) mode with the Kubernetes installer.

A load balancer is required for high availability mode. If your vendor has chosen to use the internal load balancer with the EKCO add-on, you do not need to provide your own external load balancer. An external load balancer can be preferred when clients outside the cluster need access to the cluster's Kubernetes API.

If you decide to use an external load balancer, the external load balancer must be a TCP forwarding load balancer. For more information, see Prerequisites.

The health check for an apiserver is a TCP check on the port that the kube-apiserver listens on. The default value is :6443. For more information about the kube-apiserver external load balancer, see Create load balancer for kube-apiserver in the Kubernetes documentation.

Prerequisites​

Complete the following prerequisites:

  • If you are installing in high availability mode:
    • (Optional) If you are going to use the internal load balancer, you can preconfigure it by passing | sudo bash -s ha ekco-enable-internal-load-balancer.
    • For an external load balancer, ensure that your load balancer is:
      • A TCP forwarding external load balancer.
      • Configured to distribute traffic to all healthy control plane nodes in its target list.
      • (Optional) Preconfigured by passing the load-balancer-address=HOST:PORT flag.

Install the Application​

This procedure explains how to install the the application in an online environment, with and without high availability mode.

To install the application:

  1. Run one of the following commands:

    • For the latest version of the application:

      curl -sSL https://k8s.kurl.sh/APP_SLUG | sudo bash

    • For a specific version of the application, use the app-version-label flag and the version label for a particular version of your vendor's application:

      curl https://k8s.kurl.sh/APP_SLUG | sudo bash -s app-version-label=VERSION_LABEL

    • For high availability mode:

      curl -sSL https://k8s.kurl.sh/APP_SLUG | sudo bash -s ha

    Replace, where applicable:

    • APP_SLUG with the unique slug for the application. The application slug is included in the installation command provided by the vendor.
    • VERSION_LABEL with the label for the version of the application to install. For example, --app-version-label=3.0.1.

  2. (High Availability Only) If you did not preconfigure a load balancer, you are prompted during the installation. Do one of the following:

    • If you are using the internal load balancer, leave the prompt blank and proceed with the installation.

    • If you are using an external load balancer, pass the load balancer address.

  3. Note the Kotsadm and Login with password (will not be shown again) fields in the output of the installation command.

  4. Log in to the admin console to complete the application setup, run preflight checks, and deploy. See Completing Application Setup and Deploying.

Next Step​

(Optional) You can add nodes to the cluster. See Adding Nodes to Kubernetes Installer Clusters.