Deploy to Kubernetes

The goal of this step is to create a pod in the Kubernetes cluster running the image we have pushed to the container registry

Installing IBM Cloud Kubernetes Service CLI plug-in

To create and manage Kubernetes clusters in IBM Cloud® Kubernetes Service. To install the Kubernetes Service plug-in, run the following command:

ibmcloud plugin install container-service

Download the Kubernetes CLI

Sometimes it is just better to execute directly the kubernetes commands without passing through the Kubernetes Service CLI. Download the proper CLI according to your operating system

Install for macOS and Linux:

Move the executable file to the /usr/local/bin directory using the command mv /<path_to_file>/kubectl /usr/local/bin/kubectl
Make sure that /usr/local/bin is listed in your PATH system variable.
```
 $ echo $PATH
 /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
```
Convert the binary file to an executable: chmod +x /usr/local/bin/kubectl

Install for Windows: Install the Kubernetes CLI in the same directory as the IBM Cloud CLI. This setup saves you some filepath changes when you run commands later.

Update the configuration files

In the project you can find under the folder /kubernetes you can find a simple yaml file that describes a deployment in Kubernetes: it is composed by a deployment (to create the pod) and a service.

Rename the template.deployment.yaml to deployment.yaml and change its content with the proper values such as the container registry image info.

Log in to the cluster

Make sure that you are already logged in with IBM Cloud

ibmcloud login -a https://cloud.ibm.com

❗️ If you are using a federated ID (such as via IBM), you need to add the --sso

target the resource group of your cluster

ibmcloud target -g <RESOURCE GROUP>

List the clusters in your account:
```
  ibmcloud ks clusters
```
Set an environment variable that will be used in subsequent commands in this lab
```
  export CLUSTER_NAME=<your_cluster_name>
```

Configure kubectl to point to your cluster

  ibmcloud ks cluster config --cluster $CLUSTER_NAME

Validate proper configuration

  kubectl get namespace

  NAME              STATUS   AGE
  default           Active   125m
  ibm-cert-store    Active   121m
  ibm-system        Active   124m
  kube-node-lease   Active   125m
  kube-public       Active   125m
  kube-system       Active   125m

💡 For this lab, we will use the default namespace. If you wish to deploy things to different namespaces on the cluster, remember that you need to add the -n <NAMESPACE NAME> at the end of your commands

Create config map

You can use kubectl create configmap with the --from-literal argument to define a literal value from the command line

kubectl create configmap python-simple-app-config --from-literal=PYTHON_CUSTOM_MESSAGE="Hello from the cloud"

Apply the configuration

kubectl apply -f kubernetes/deployment.yaml

Check everything is working as expected

Check pods are in Running state

kubectl get pods

Check service exists

kubectl get services

kubectl get services
NAME                TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes          ClusterIP   172.21.0.1      <none>        443/TCP          10h
python-simple-app   NodePort    172.21.73.100   <none>        8080:32459/TCP   7s

Connect to the application

The free cluster unfortunately does not come with an Application Load Balancer (ALB), so we do not have an Ingress component that we can use to obtain an hostname to connect to. As a workaround, we will directly contact the PUBLIC IP of the worker node and we will use the port exposed

To find the port used on the worker node, examine your new service

 kubectl get services

 NAME                TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
 kubernetes          ClusterIP   172.21.0.1       <none>        443/TCP          10h
 python-simple-app   NodePort    172.21.151.240   <none>        8080:32189/TCP   2m48s

in my scenario the port is the 32189 for the service python-simple-app

obtain the EXTERNAL IP of your worker node

 kubectl get nodes -o wide

 NAME             STATUS   ROLES    AGE   VERSION       INTERNAL-IP      EXTERNAL-IP       OS-IMAGE             KERNEL-VERSION       CONTAINER-RUNTIME
 10.144.214.101   Ready    <none>   10h   v1.22.8+IKS   10.144.214.101   159.122.177.130   Ubuntu 18.04.6 LTS   4.15.0-175-generic   containerd://1.5.11

in my scenario the IP is 159.122.177.130

Open a browser window at http://<EXTERNAL_IP>:<PORT> and everything should be working!