Oracle by Example brandingCreate a Cluster with Oracle Cloud Infrastructure Container Engine for Kubernetes

section 0Before You Begin

This 10-minute tutorial shows you how to:

  • create a new cluster with default settings and new network resources
  • create a node pool
  • download the kubeconfig file for the cluster
  • verify you can access the cluster using kubectl and the Kubernetes Dashboard

Background

Oracle Cloud Infrastructure Container Engine for Kubernetes is a fully-managed, scalable, and highly available service that you can use to deploy your containerized applications to the cloud. Use Container Engine for Kubernetes when your development team wants to reliably build, deploy, and manage cloud-native applications. You specify the compute resources that your applications require, and Container Engine for Kubernetes provisions them on Oracle Cloud Infrastructure in an existing OCI tenancy.

In this tutorial, you use default settings to define a new cluster. When you create the new cluster, new network resources for the cluster are created automatically, along with a node pool and three private worker nodes. You'll then download the Kubernetes configuration file for the cluster (the cluster's 'kubeconfig' file). The kubeconfig file enables you to access the cluster using kubectl and the Kubernetes Dashboard.

What Do You Need?

  • An Oracle Cloud Infrastructure username and password.
  • Within the root compartment of your tenancy, a policy statement Allow service OKE to manage all-resources in tenancy must be defined to give Container Engine for Kubernetes access to resources in the tenancy.
  • Within your tenancy, there must already be a compartment to contain the necessary network resources (VCN, subnets, internet gateway, NAT gateway, route table, security lists). If such a compartment does not exist already, you will have to create it before starting this tutorial.
  • At least three compute instances must be available in the tenancy to complete this tutorial as described. Note that if only one compute instance is available, it is possible to create a cluster with a node pool that has a single subnet and a single node in the node pool. However, such a cluster will not be highly available.
  • To create and/or manage clusters, you must belong to one of the following:
    • The tenancy's Administrators group.
    • A group to which a policy grants the appropriate Container Engine for Kubernetes permissions. As you'll be creating and configuring a cluster and associated network resources during the tutorial, policies must also grant the group the appropriate permissions on those resources. For more details and examples, see the Policy Configuration for Cluster Creation and Deployment topic in the Container Engine for Kubernetes documentation.
  • Before you download the kubeconfig file later in the tutorial, you must have already done the following (if you haven't, or you're not sure, see the Downloading a kubeconfig File to Enable Cluster Access topic in the Container Engine for Kubernetes documentation):
    • generated an API signing key pair
    • added the public key value of the API signing key pair to the User Settings for your username
    • installed and configured the Oracle Cloud Infrastructure CLI
  • You must have installed and configured the Kubernetes command line tool kubectl. If you haven't done so already, see the kubectl documentation.

section 1Starting OCI

  1. In a browser, go to the url you've been given to log in to Oracle Cloud Infrastructure.
  2. Sign In page
    Description of the illustration
  3. Specify a tenant in which you have the appropriate permissions to create clusters. You inherit these permissions in one of the following ways:
    • By belonging to the tenancy's Administrators group.
    • By belonging to another group to which a policy grants the appropriate Container Engine for Kubernetes permissions. As you'll be creating and configuring a cluster and associated network resources during the tutorial, policies must also grant the group the permissions listed in the What Do You Need? section.
  4. Enter your username and password.

section 2Define Cluster Details

  1. In the Console, open the navigation menu. Under Solutions, Platform and Edge, go to Developer Services and click Container Clusters.
  2. Choose a Compartment that you have permission to work in, and in which you want to create both the new cluster and the associated network resources.
  3. Clusters page
    Description of the illustration
  4. On the Clusters page, click Create Cluster. The examples shown in this tutorial assume you give the new cluster the name Tutorial Cluster.
    Cluster Creation dialog
    Description of the illustration
  5. In the Cluster Creation dialog, change the placeholder value in the Name field and enter Tutorial Cluster instead.
  6. Select the Quick Create option to indicate you want to create a new cluster with default settings, along with new network resources for the new cluster.
  7. Cluster Creation dialog
    Description of the illustration
  8. Click Create to create the new network resources and the new cluster.
  9. Cluster Creation dialog
    Description of the illustration
    You see the different network resources being created for you.
    Cluster Creation Status dialog
    Description of the illustration
  10. Click Close to return to the Console.
  11. Cluster Creation Status dialog
    Description of the illustration
    The new cluster is shown on the Cluster Details page. When it has been created, the new cluster has a status of Active.
    Cluster Details page
    Description of the illustration
  12. Scroll down to see details of the new node pool that has been created, along with details of the new worker nodes (compute instances).
  13. Cluster Details page
    Description of the illustration

section 3Download the kubeconfig File for the Cluster

  1. Confirm that you've already done the following:
    • Generated an API signing key pair.
    • Added the public key value of the API signing key pair to the User Settings for your username.
    • Installed and configured the Oracle Cloud Infrastructure CLI.

    If you haven't done one or more of the above, or you're not sure, see the Downloading a kubeconfig File to Enable Cluster Access topic in the Container Engine for Kubernetes documentation.

  2. With the Cluster Details page showing the Tutorial Cluster, click Access Kubeconfig to display the How to Access Kubeconfig dialog box.
    How to Access Kubeconfig dialog
    Description of the illustration
  3. In a terminal window, create a directory to contain the kubeconfig file, giving the directory the expected default name  and location of $HOME/.kube. For example, on Linux, enter the following command (or copy and paste it from the How to Access Kubeconfig dialog box): 
  4. $ mkdir -p $HOME/.kube
  5. Run the Oracle Cloud Infrastructure CLI command to download the kubeconfig file and save it with the expected default name and location of $HOME/.kube/config. This name and location ensures the kubeconfig file is accessible to kubectl and the Kubernetes Dashboard whenever you run them from a terminal window. For example, on Linux, enter the following command (or copy and paste it from the How to Access Kubeconfig dialog box):
    $ oci ce cluster create-kubeconfig --cluster-id ocid1.cluster.oc1.phx.aaaaaaaaae... --file $HOME/.kube/config  --region us-phoenix-1
    where ocid1.cluster.oc1.phx.aaaaaaaaae... is the OCID of the current cluster. For convenience, the command in the How to Access Kubeconfig dialog box already includes the cluster's OCID.
  6. Set the value of the KUBECONFIG environment variable to the name and location of the kubeconfig file. For example, on Linux, enter the following command (or copy and paste it from the How to Access Kubeconfig dialog box): 
    $ export KUBECONFIG=$HOME/.kube/config
  7. Click Close to close the How to Access Kubeconfig dialog.

section 4Verify kubectl and Kubernetes Dashboard Access to the Cluster

  1. Confirm that you've already installed kubectl. If you haven't done so already, see the kubectl documentation.
  2. Verify that you can use kubectl to connect to the new cluster you've created. In a terminal window, enter the following command:
    $ kubectl get nodes
    You see details of the nodes running in the cluster. For example:
    NAME              STATUS  ROLES  AGE  VERSION
    10.0.10.2         Ready   node   1d   v1.11.5
    10.0.11.2         Ready   node   1d   v1.11.5
    10.0.12.2         Ready   node   1d   v1.11.5
    
  3. Verify that you can use the Kubernetes Dashboard to connect to the cluster:
    1. In a terminal window, enter the following command:
      $ kubectl proxy
    2. Open a new browser window and go to http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/ to display the Kubernetes Dashboard.
      Kubernetes Dashboard Sign In page
      Description of the illustration
    3. Select the Kubeconfig option, click Choose kubeconfig file, and select the kubeconfig file that you downloaded earlier.
    4. Click Sign In.
    5. Click Overview to see that Kubernetes is the only service running in the cluster.
      Kubernetes Dashboard Overview page
      Description of the illustration
    6. Congratulations! You've successfully created a new cluster, and confirmed that the new cluster is up and running as expected.


section 5Housekeeping (optional)

Having completed the tutorial, if you want to free up Oracle Cloud Infrastructure resources, you can now delete the VCN and the cluster that you created. On the other hand, it's a good idea to retain them (especially the VCN) for your own testing purposes. If you intend to follow the Pulling an Image from Oracle Cloud Infrastructure Registry when Deploying a Load-Balanced Application to a Cluster tutorial, definitely don't delete the VCN and the cluster because you will use them in that tutorial.

  1. (optional) Go back to the browser window with the Cluster Details page showing the Tutorial Cluster, click Delete Cluster and confirm that you want to delete the Tutorial Cluster you created.
    Cluster Details page
    Description of the illustration
  2. (optional) Delete the VCN created during the tutorial:
    1. In the Console, open the navigation menu. Under Core Infrastructure, go to Networking and click Virtual Cloud Networks.
    2. Locate the VCN you created during this tutorial.
    3. Click the Actions icon beside the VCN, and then click Terminate.
      VCN page
      Description of the illustration
    4. Confirm that you want to terminate the VCN.

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