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      Deploy and Manage a Cluster with Linode Kubernetes Engine and the Linode API – A Tutorial


      Updated by Linode Contributed by Linode

      Note

      Linode Kubernetes Engine (LKE) is currently in Private Beta, and you may not have access to LKE through the Cloud Manager or other tools. To request access to the Private Beta, sign up here. Beta access awards you $100/month in free credits for the duration of the beta, which is automatically applied to your account when an LKE cluster is in use. Additionally, you will have access to the Linode Green Light community, a new program connecting beta users with our product and engineering teams.

      Additionally, because LKE is in Beta, there may be breaking changes to how you access and manage LKE. This guide will be updated to reflect these changes if and when they occur.

      What is the Linode Kubernetes Engine (LKE)?

      The Linode Kubernetes Engine (LKE) is a fully-managed container orchestration engine for deploying and managing containerized applications and workloads. LKE combines Linode’s ease of use and simple pricing with the infrastructure efficiency of Kubernetes. When you deploy a LKE cluster, you receive a Kubernetes Master at no additional cost; you only pay for the Linodes (worker nodes), NodeBalancers (load balancers), and Block Storage Volumes. Your LKE Cluster’s Master node runs the Kubernetes control plane processes – including the API, scheduler, and resource controllers.

      Additional LKE features

      • etcd Backups : A snapshot of your cluster’s metadata is backed up continuously, so your cluster is automatically restored in the event of a failure.
      • High Availability : All of your control plane components are monitored and will automatically recover if they fail.

      You can easily deploy an LKE cluster in several ways:

      These Linode-provided interfaces can be used to create, delete, and update the structural elements of your cluster, including:

      • The number of nodes that make up a cluster’s node pools.
      • The region where your node pools are deployed.
      • The hardware resources for each node in your node pools.
      • The Kubernetes version deployed to your cluster’s Master node and worker nodes.

      The Kubernetes API and kubectl are the primary ways you will interact with your LKE cluster once it’s been created. These tools can be used to configure, deploy, inspect, and secure your Kubernetes workloads, deploy applications, create services, configure storage and networking, and define controllers.

      In this Guide

      This guide will cover how to use the Linode API to:

      Before You Begin

      1. Familiarize yourself with the Linode Kubernetes Engine service. This information will help you understand the benefits and limitations of LKE.

      2. Create an API Token. You will need this to access the LKE service.

      3. Install kubectl on your computer. You will use kubectl to interact with your cluster once it’s deployed.

      4. If you are new to Kubernetes, refer to our A Beginner’s Guide to Kubernetes series to learn about general Kubernetes concepts. This guide assumes a general understanding of core Kubernetes concepts.

      Enable Network Helper

      In order to use the Linode Kubernetes Engine, you will need to have Network Helper enabled globally on your account. Network Helper is a Linode-provided service that automatically sets a static network configuration for your Linode when it boots. To enable this global account setting, follow these instructions.

      If you don’t want to use Network Helper on some Linodes that are not part of your LKE clusters, the service can also be disabled on a per-Linode basis; see instructions here.

      Note

      If you have already deployed an LKE cluster and did not enable Network Helper, you can add a new node pool with the same type, size, and count as your initial node pool. Once your new node pool is ready, you can then delete the original node pool.

      Install kubectl

      macOS:

      Install via Homebrew:

      brew install kubernetes-cli
      

      If you don’t have Homebrew installed, visit the Homebrew home page for instructions. Alternatively, you can manually install the binary; visit the Kubernetes documentation for instructions.

      Linux:

      1. Download the latest kubectl release:

        curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl
        
      2. Make the downloaded file executable:

        chmod +x ./kubectl
        
      3. Move the command into your PATH:

        sudo mv ./kubectl /usr/local/bin/kubectl
        

      Note

      Windows:

      Visit the Kubernetes documentation for a link to the most recent Windows release.

      Create an LKE Cluster

      Required Parameters Description
      region The data center region where your cluster will be deployed. Currently, us-central is the only available region for LKE clusters.
      label A human readable name to identify your cluster. This must be unique. If no label is provided, one will be assigned automatically. Labels must start with an alpha [a-z][A-Z] character, must only consist of alphanumeric characters and dashes, and must not contain two dashes in a row.
      node_pools The collections of Linodes that serve as the worker nodes in your LKE cluster.
      version The desired version of Kubernetes for this cluster.
      1. To create an LKE Cluster, send a POST request to the /lke/clusters endpoint. The example below displays all possible request body parameters. Note that tags is an optional parameter.

        curl -H "Content-Type: application/json" 
             -H "Authorization: Bearer $TOKEN" 
             -X POST -d '{
                "label": "cluster12345",
                "region": "us-central",
                "version": "1.16",
                "tags": ["ecomm", "blogs"],
                "node_pools": [
                  { "type": "g6-standard-2", "count": 2},
                  { "type": "g6-standard-4", "count": 3}
                ]
             }' https://api.linode.com/v4/lke/clusters
        

        You will receive a response similar to:

          
        {"version": "1.16", "updated": "2019-08-02T17:17:49", "region": "us-central", "tags": ["ecomm", "blogs"], "label": "cluster12345", "id": 456, "created": "2019-22-02T17:17:49"}%
            
        
      2. Make note of your cluster’s ID, as you will need it to continue to interact with your cluster in the next sections. In the example above, the cluster’s ID is "id": 456. You can also access your cluster’s ID by listing all LKE Clusters on your account.

        Note

        Each Linode account has a limit to the number of Linode resources they can deploy. This includes services, like Linodes, NodeBalancers, Block Storage, etc. If you run into issues deploying the number of nodes you designate for a given cluster’s node pool, you may have run into a limit on the number of resources allowed on your account. Contact Linode Support if you believe this may be the case.

      Connect to your LKE Cluster

      Now that your LKE cluster is created, you can access and manage your cluster using kubectl on your computer. This will give you the ability to interact with the Kubernetes API, and to create and manage Kubernetes objects in your cluster.

      To communicate with your LKE cluster, kubectl requires a copy of your cluster’s kubeconfig. In this section, you will access the contents of your kubeconfig using the Linode API and then set up kubectl to communicate with your LKE cluster.

      1. Access your LKE cluster’s kubeconfig file by sending a GET request to the /lke/clusters/{clusterId}/kubeconfig endpoint. Ensure you replace 12345 with your cluster’s ID that you recorded in the previous section:

        curl -H "Authorization: Bearer $TOKEN" 
          https://api.linode.com/v4/lke/clusters/12345/kubeconfig
        

        The API returns a base64 encoded string (a useful format for automated pipelines) representing your kubeconfig. Your output will resemble the following:

          
        {"kubeconfig": "YXBpVmVyc2lvbjogdjEKY2x1c3RlcnM6Ci0gY2x1c3RlcjoKICAgIGNlcnRpZmljYXRlLWF1dGhvcml0eS1kYXRhOiBMUzB0TFMxQ1JVZEpUaUJEUlZKVVNVWkpRMEZVUlMwdExTMHRDazFKU1VONVJFTkRRV0pEWjBGM1NVSkJaMGxDUVVSQlRrSm5hM0ZvYTJsSE9YY3dRa0ZSYzBaQlJFRldUVkpOZDBWUldVUldVVkZFUlhkd2NtUlhTbXdLWTIwMWJHUkhWbnBOUWpSWVJGUkZOVTFFWjNkTmFrVXpUVlJqTVUxV2IxaEVWRWsx ... 0TFMwdExRbz0K"}%
        
        
      2. Copy the kubeconfig field’s value from the response body, since you will need it in the next step.

        Note

        Make sure you only copy the long string inside the quotes following "kubeconfig": in your output. Do not copy the curly braces or anything outside of them. You will receive an error if you use the full output in later steps.

      3. Save the base64 kubeconfig to an environment variable:

        KUBE_VAR='YXBpVmVyc2lvbjogdjEK ... 0TFMwdExRbz0K'
        
      4. Navigate to your computer’s ~/.kube directory. This is where kubectl looks for kubeconfig files, by default.

        cd ~/.kube
        
      5. Create a directory called configs within ~/.kube. You can use this directory to store your kubeconfig files.

        mkdir configs
        cd configs
        
      6. Decode the contents of $KUBE_VAR and save it to a new YAML file:

        echo $KUBE_VAR | base64 -D > cluster12345-config.yaml
        

        Note

        The YAML file that you decode to (cluster12345-config.yaml here) can have any name of your choosing.

      7. Add the kubeconfig file to your $KUBECONFIG environment variable.

        export KUBECONFIG=cluster12345-config.yaml
        
      8. Verify that your cluster is selected as kubectl’s current context:

        kubectl config get-contexts
        
      9. View the contents of the configuration:

        kubectl config view
        

        Note

      10. View all nodes in your LKE cluster using kubectl:

        kubectl get nodes
        

        Your output will resemble the following example, but will vary depending on your own cluster’s configurations.

          
        NAME                      STATUS   ROLES  AGE     VERSION
        lke166-193-5d44703cd092   Ready    none   2d22h   v1.14.0
        lke166-194-5d44703cd780   Ready    none   2d22h   v1.14.0
        lke166-195-5d44703cd691   Ready    none   2d22h   v1.14.0
        lke166-196-5d44703cd432   Ready    none   2d22h   v1.14.0
        lke166-197-5d44703cd211   Ready    none   2d22h   v1.14.0
        
        

        Now that you are connected to your LKE cluster, you can begin using kubectl to deploy applications, inspect and manage cluster resources, and view logs.

      Persist the Kubeconfig Context

      If you create a new terminal window, it will not have access to the context that you specified using the previous instructions. This context information can be made persistent between new terminals by setting the KUBECONFIG environment variable in your shell’s configuration file.

      Note

      These instructions will persist the context for users of the Bash terminal. They will be similar for users of other terminals:

      1. Open up your Bash profile (e.g. ~/.bash_profile) in the text editor of your choice and add your configuration file to the $KUBECONFIG PATH variable.

        If an export KUBECONFIG line is already present in the file, append to the end of this line as follows; if it is not present, add this line to the end of your file:

        export KUBECONFIG:$KUBECONFIG:$HOME/.kube/config:$HOME/.kube/configs/cluster12345-config.yaml
        

        Note

        Alter the $HOME/.kube/configs/cluster12345-config.yaml path in the above line with the name of the file you decoded to in the previous section.

      2. Close your terminal window and open a new window to receive the changes to the $KUBECONFIG variable.

      3. Use the config get-contexts command for kubectl to view the available cluster contexts:

        kubectl config get-contexts
        

        You should see output similar to the following:

          
        CURRENT  NAME                         CLUSTER     AUTHINFO          NAMESPACE
        *        [email protected]  kubernetes  kubernetes-admin
        
        
      4. If your context is not already selected, (denoted by an asterisk in the current column), switch to this context using the config use-context command. Supply the full name of the cluster (including the authorized user and the cluster):

        kubectl config use-context [email protected]
        

        You should see output like the following:

          
        Switched to context "[email protected]".
        
        
      5. You are now ready to interact with your cluster using kubectl. You can test the ability to interact with the cluster by retrieving a list of Pods in the kube-system namespace:

        kubectl get pods -n kube-system
        

      Inspect your LKE Cluster

      Once you have created an LKE Cluster, you can access information about its structural configuration using the Linode API.

      List LKE Clusters

      To view a list of all your LKE clusters, send a GET request to the /lke/clusters endpoint.

      curl -H "Authorization: Bearer $TOKEN" 
          https://api.linode.com/v4/lke/clusters
      

      The returned response body will display the number of clusters deployed to your account and general details about your LKE clusters:

        
      {"results": 2, "data": [{"updated": "2019-08-02T17:17:49", "region": "us-central", "id": 456, "version": "1.16", "label": "cluster-12345", "created": "2019-08-02T17:17:49", "tags": ["ecomm", "blogs"]}, {"updated": "2019-08-05T17:00:04", "region": "us-central", "id": 789, "version": "1.16", "label": "cluster-56789", "created": "2019-08-05T17:00:04", "tags": ["ecomm", "marketing"]}], "pages": 1, "page": 1}%
      
      

      View an LKE Cluster

      You can use the Linode API to access details about an individual LKE cluster. You will need your cluster’s ID to access information about this resource. If you don’t know your cluster’s ID, see the List LKE Clusters section.

      Required Parameters Description
      clusterId ID of the LKE cluster to lookup.

      To view your LKE cluster, send a GET request to the the /lke/clusters/{clusterId} endpoint. In this example, ensure you replace 12345 with your cluster’s ID:

      curl -H "Authorization: Bearer $TOKEN" 
              https://api.linode.com/v4/lke/clusters/12345
      

      Your output will resemble the following:

        
      {"created": "2019-08-02T17:17:49", "updated": "2019-08-02T17:17:49", "version": "1.16", "tags": ["ecomm", "blogs"], "label": "cluster-12345", "id": 456, "region": "us-central"}%
      
      

      List a Cluster’s Node Pools

      A node pool consists of one or more Linodes (worker nodes). Each node in the pool has the same plan type. Your LKE cluster can have several node pools. Each pool is assigned its own plan type and number of nodes. To view a list of an LKE cluster’s node pools, you need your cluster’s ID. If you don’t know your cluster’s ID, see the List LKE Clusters section.

      Required Parameters Description
      clusterId ID of the LKE cluster to lookup.

      To list your cluster’s node pools, send a GET request to the /lke/clusters/{clusterId}/pools endpoint. In this example, replace 12345 with your cluster’s ID:

      curl -H "Authorization: Bearer $TOKEN" 
          https://api.linode.com/v4/lke/clusters/12345/pools
      

      The response body will include information on each node pool’s pool ID, Linode type, and node count; and each node’s individual ID and status.

        
      {"pages": 1, "page": 1, "data": [{"count": 2, "id": 193, "type": "g6-standard-2", "linodes": [{"id": "13841932", "status": "ready "}, {"id": "13841933", "status": "ready"}]}, {"count": 3, "id": 194, "type": "g6-standard-4", "linodes": [{"id": "13841934", "status": "ready"}, {"id": "13841935", "status": "ready"}, {"id": "13841932", "status": "ready"}]}], "results": 2}%
      
      

      View a Node Pool

      You can use the Linode API to access details about a specific node pool in an LKE cluster. You will need your cluster’s ID and node pool ID to access information about this resource. To retrieve your cluster’s ID, see the List LKE Clusters section. To find a node pool’s ID, see the List a Cluster’s Node Pools section.

      Required Parameters Description
      clusterId ID of the LKE cluster to lookup.
      poolId ID of the LKE node pool to lookup.

      To view a specific node pool, send a GET request to the /lke/clusters/{clusterId}/pools/{poolId} endpoint. In this example, replace 12345 with your cluster’s ID and 456 with the node pool’s ID:

      curl -H "Authorization: Bearer $TOKEN" 
          https://api.linode.com/v4/lke/clusters/12345/pools/456
      

      The response body provides information about the number of nodes in the node pool, the node pool’s ID, and type. You will also retrieve information about each individual node in the node pool, including the Linode’s ID and status.

        
      {"count": 2, "id": 193, "type": "g6-standard-2", "linodes": [{"id": "13841932", "status": "ready"}, {"id": "13841933", "status": "ready"}]}%
      
      

      Note

      If desired, you can use your node pool’s Linode ID(s) to get more details about each node in the pool. Send a GET request to the /linode/indstances/{linodeId} endpoint. In this example, ensure you replace 13841932 with your Linode’s ID.

      curl -H "Authorization: Bearer $TOKEN" 
          https://api.linode.com/v4/linode/instances/13841932
      

      Although you have access to your cluster’s nodes, it is recommended that you only interact with your nodes via the Linode’s LKE interfaces (like the LKE endpoints in Linode’s API, or the Kubernetes section in the Linode Cloud Manager), or via the Kubernetes API and kubectl.

      Modify your LKE Cluster

      Once an LKE cluster is created, you can modify two aspects of it: the cluster’s label, and the cluster’s node pools. In this section you will learn how to modify each of these parts of your cluster.

      Update your LKE Cluster Label

      Required Parameters Description
      clusterId ID of the LKE cluster to lookup.

      To update your LKE cluster’s label, send a PUT request to the /lke/clusters/{clusterId} endpoint. In this example, ensure you replace 12345 with your cluster’s ID:

      curl -H "Content-Type: application/json" 
              -H "Authorization: Bearer $TOKEN" 
              -X PUT -d '{
              "label": "updated-cluster-name"
              }' https://api.linode.com/v4/lke/clusters/12345
      

      The response body will display the updated cluster label:

        
      {"created": "2019-08-02T17:17:49", "updated": "2019-08-05T19:11:19", "version": "1.16", "tags": ["ecomm", "blogs"], "label": "updated-cluster-name", "id": 456, "region": "us-central"}%
      
      

      Add a Node Pool to your LKE Cluster

      A node pool consists of one or more Linodes (worker nodes). Each node in the pool has the same plan type and is identical to each other. Your LKE cluster can have several node pools, each pool with its own plan type and number of nodes.

      You will need your cluster’s ID in order to add a node pool to it. If you don’t know your cluster’s ID, see the List LKE Clusters section.

      Required Parameters Description
      clusterId ID of the LKE cluster to lookup.
      type The Linode plan type to use for all the nodes in the pool. Linode plans designate the type of hardware resources applied to your instance.
      count The number of nodes to include in the node pool. Each node will have the same plan type.

      To add a node pool to an existing LKE cluster, send a POST request to the /lke/clusters/{clusterId}/pools endpoint. The request body must include the type and count parameters. In the URL of this example, ensure you replace 12345 with your own cluster’s ID:

      curl -H "Content-Type: application/json" 
              -H "Authorization: Bearer $TOKEN" 
              -X POST -d '{
              "type": "g6-standard-1",
              "count": 5
              }' https://api.linode.com/v4/lke/clusters/12345/pools
      

      The response body will resemble the following:

        
      {"count": 5, "id": 196, "type": "g6-standard-1", "linodes": [{"id": "13841945", "status": "ready"}, {"id": "13841946", "status": "ready"}, {"id": "13841947", "status": "ready"}, {"id": "13841948", "status": "ready"}, {"id": "13841949", "status": "ready"}]}%
      
      

      Note

      Each Linode account has a limit to the number of Linode resources they can deploy. This includes services, like Linodes, NodeBalancers, Block Storage, etc. If you run into issues deploying the number of nodes you designate for a given cluster’s node pool, you may have run into a limit on the number of resources allowed on your account. Contact Linode Support if you believe this may be the case.

      Resize your LKE Node Pool

      You can resize an LKE cluster’s node pool to add or decrease its number of nodes. You will need your cluster’s ID and the node pool’s ID in order to resize it. If you don’t know your cluster’s ID, see the List LKE Clusters section. If you don’t know your node pool’s ID, see the List a Cluster’s Node Pools section.

      Note

      You cannot modify an existing node pool’s plan type. If you would like your LKE cluster to use a different node pool plan type, you can add a new node pool to your cluster with the same number of nodes to replace the current node pool. You can then delete the node pool that is no longer needed.
      Required Parameters Description
      clusterId ID of the LKE cluster to lookup.
      poolId ID of the LKE node pool to lookup.
      count The number of Linodes in the node pool.

      To update your node pool’s node count, send a PUT request to the /lke/clusters/{clusterId}/pools/{poolId} endpoint. In the URL of this example, replace 12345 with your cluster’s ID and 196 with your node pool’s ID:

      curl -H "Content-Type: application/json" 
          -H "Authorization: Bearer $TOKEN" 
          -X PUT -d '{
              "type": "g6-standard-4",
              "count": 6
          }' https://api.linode.com/v4/lke/clusters/12345/pools/196
      

      Note

      Each Linode account has a limit to the number of Linode resources they can deploy. This includes services, like Linodes, NodeBalancers, Block Storage, etc. If you run into issues deploying the number of nodes you designate for a given cluster’s node pool, you may have run into a limit on the number of resources allowed on your account. Contact Linode Support if you believe this may be the case.

      Delete a Node Pool from an LKE Cluster

      When you delete a node pool you also delete the Linodes (nodes) and routes to them. The Pods running on those nodes are evicted and rescheduled. If you have assigned Pods to the deleted Nodes, the Pods might remain in an unschedulable condition if no other node in the cluster satisfies the node selector.

      Required Parameters Description
      clusterId ID of the LKE cluster to lookup.
      poolId ID of the LKE node pool to lookup.

      To delete a node pool from a LKE cluster, send a DELETE request to the /lke/clusters/{clusterId}/pools/{poolId} end point. In the URL of this example, replace 12345 with your cluster’s ID and 196 with your cluster’s node pool ID:

      Caution

      This step is permanent and will result in the loss of data.

      curl -H "Authorization: Bearer $TOKEN" 
          -X DELETE 
          https://api.linode.com/v4/lke/clusters/12345/pools/196
      

      Delete an LKE Cluster

      Deleting an LKE cluster will delete the Master node, all worker nodes, and all NodeBalancers created by the cluster. However, it will not delete any Volumes created by the LKE cluster.

      To delete an LKE Cluster, send a DELETE request to the /lke/clusters/{clusterId} endpoint. In the URL of this example, replace 12345 with your cluster’s ID:

      Caution

      This step is permanent and will result in the loss of data.

      curl -H "Authorization: Bearer $TOKEN" 
          -X DELETE 
          https://api.linode.com/v4/lke/clusters/12345
      

      Where to Go From Here?

      Now that you have created an LKE cluster, you can start deploying workloads to it. Review these guides for further help:

      Find answers, ask questions, and help others.

      This guide is published under a CC BY-ND 4.0 license.



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