Building a CD Pipeline Using LKE (Part 3): Deploying the LKE Cluster

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Slide deck: Cloud Native Continuous Deployment with GitLab, Helm, and Linode Kubernetes Engine: Deploying our LKE Cluster (Slide #51)

Deploying the LKE Cluster

Managed Kubernetes clusters are much easier to setup and maintain than self-managed Kubernetes clusters. This portion goes over setting up a cluster using the Linode Kubernetes Engine (LKE) through the Cloud Manager and the Linode CLI.

Navigate the Series

• Main guide: Building a Continuous Deployment Pipeline Using LKE
• Previous section: Part 2: Sample Application
• Next section: Part 4: Kubernetes Review

Presentation Text

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Deploying our LKE cluster

• If we wanted to deploy Kubernetes manually, what would we need to do? (not that I recommend doing that…)
• Control plane (etcd, API server, scheduler, controllers)
• Nodes (VMs with a container engine + the kubelet agent; CNI setup)
• High availability (etcd clustering, API load balancer)
• Security (CA and TLS certificates everywhere)
• Cloud integration (to provision LoadBalancer services, storage…)

And that’s just to get a basic cluster!

The best way to deploy Kubernetes

“The best way to deploy Kubernetes is to get someone else to do it for us.”

- Me, ever since I’ve been working with Kubernetes

Managed Kubernetes

• Cloud provider runs the control plane (including etcd, API load balancer, TLS setup, cloud integration)
• We run nodes (the cloud provider generally gives us an easy way to provision them)
• Get started in minutes
• We’re going to use Linode Kubernetes Engine

Creating a cluster

• With the web console: https://cloud.linode.com/kubernetes/clusters
• Pick the region of your choice
• Pick the latest available Kubernetes version
• Pick 3 nodes with 8 GB of RAM
• Click! ✨
• Wait a few minutes… ⌚️
• Download the kubeconfig file 💾

With the CLI

• View available regions with linode-cli regions list

• View available server types with linode-cli linodes types

• View available Kubernetes versions with linode-cli lke versions-list

• Create cluster:

  linode-cli lke cluster-create --label=hello-lke --region=us-east \
    --k8s_version=1.20 --node_pools.type=g6-standard-4 --node_pools.count=3
  

• Note the cluster ID (e.g.: 12345)

• Download the kubeconfig file:

  linode-cli lke kubeconfig-view `12345` --text --no-headers | base64 -d
  

Communicating with the cluster

• All the Kubernetes tools (kubectl, but also helm etc) use the same config file
• That file is (by default) $HOME/.kube/config
• It can hold multiple cluster definitions (or contexts)
• Or, we can have multiple config files and switch between them:
  • by adding the --kubeconfig flag each time we invoke a tool (🙄)
  • or by setting the KUBECONFIG environment variable (☺️)

Using the kubeconfig file

Option 1:

• move the kubeconfig file to e.g. ~/.kube/config.lke
• set the environment variable: export KUBECONFIG=~/.kube/config.lke

Option 2:

• directly move the kubeconfig file to ~/.kube/config
• do not do that if you already have a file there!

Option 3:

• merge the new kubeconfig file with our existing file

Merging kubeconfig

• Assuming that we want to merge ~/.kube/config and ~/.kube/config.lke …

• Move our existing kubeconfig file:

  cp ~/.kube/config ~/.kube/config.old
  

• Merge both files:

  KUBECONFIG=~/.kube/config.old:~/.kube/config.lke kubectl config \
      view --raw > ~/.kube/config
  

• Check that everything is there:

  kubectl config get-contexts
  

Are we there yet?

• Let’s check if our control plane is available: kubectl get services. This should show the kubernetes ClusterIP service
• Look for our nodes: kubectl get nodes. This should show 3 nodes (or whatever amount we picked earlier)
• If the nodes aren’t visible yet, give them a minute to join the cluster