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3 Easy Methods to Deploy/Create Pods in Kubernetes Cluster

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In this tutorial, I will take you through 3 easy ways to deploy/create pods in Kubernetes. If you are using docker from long time then you might be aware that docker uses containers to deploy applications in a Server which is very specific to that Server and cannot be shared or migrate to another Server. If you are looking to create a container independent architecture where applications can be deployed without depending on a specific resource then Kubernetes pods are the most suitable. More can be checked on Kubernetes Documentation.

What are Pods

Pods are the most basic unit in Kubernetes Cluster where application can be deployed either in a single container environment or in multiple container environment.

Pods uses an overlaying network architecture in Kubernetes to communicate internally with each other and then it also has an external IP to communicate with outside world. A pod running on multiple containers can share same resources.

3 Easy Methods to Deploy/Create Pods in Kubernetes Cluster

3 Easy Methods to Deploy/Create Pods in Kubernetes Cluster

Also Read: How to Create New Custom Namespaces in Kubernetes{3 Best Methods} 

Method 1: Deploy/Create Pods in Kubernetes Cluster Using YAML File

One of the method which is used extensively by Kubernetes professional is through YAML File. You can specify all the resources like name of pod, label, image, ports etc required to create pod in a YAML File and then create it using a single line command. Here we are creating a pod web-app in current namespace using nginx image and container running on Port 80.

[root@localhost ~]# vi pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: web-app
labels:
role: approle
spec:
containers:
- name: web-app-cont
image: nginx
ports:
- name: web-app-port
containerPort: 80
protocol: TCP

After providing all the pod configuration on pod.yaml file, we are creating the pod by using kubectl apply -f pod.yaml command as shown below.

[root@localhost ~]# kubectl apply -f pod.yaml
pod/web-app created

If everything goes well then you will be able to see web-app pod in running state using kubectl get pods | grep -i web-app command as shown below.

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[root@localhost ~]# kubectl get pods | grep -i web-app
web-app 1/1 Running 0 26s

If you want you can also delete the pod by using kubectl delete pod web-app command. This will simply remove the pod along with its resources from Kubernetes Cluster.

[root@localhost ~]# kubectl delete pod web-app
pod "web-app" deleted

Method 2: Deploy/Create Pods in Kubernetes Cluster Using JSON File

The second method that you might need to use is through JSON File. Ideally if you have YAML file then you can just rename that file to .json and use it as JSON file like we are doing it here. We just have taken pod.yaml file from above method and renamed it to pod.json using mv pod.yaml pod.json command as shown below.

[root@localhost ~]# mv pod.yaml pod.json

Then creating the pod from pod.json file by simply using kubectl create -f pod.json command as shown below.

[root@localhost ~]# kubectl create -f pod.json
pod/web-app created

You can also verify the pod.json contents by opening the file using our favorite vi editor as shown below. Alternatively you can also use cat pod.json command to view the contents.

[root@localhost ~]# vi pod.json
apiVersion: v1
kind: Pod
metadata:
name: web-app
labels:
role: approle
spec:
containers:
- name: web-app-cont
image: nginx
ports:
- name: web-app-port
containerPort: 80
protocol: TCP

Once the pod is created you can verify its status by running kubectl get pods | grep -i web-app command.

[root@localhost ~]# kubectl get pods | grep -i web-app
web-app 1/1 Running 0 34s

Method 3: Deploy/Create Pods in Kubernetes Cluster Using kubectl command

There is another method that you can use is through command line interface where you can just run a command to create pod in kubernetes cluster as shown below. Syntax for creating pod will be kubectl create deployment <pod_name> --image=<image_name>. Here we are creating web-app pod by using kubectl create deployment web-app --image=nginx command.

[root@localhost ~]# kubectl create deployment web-app --image=nginx
deployment.apps/web-app created

Above command will create a web-app deployment which will further create web-app-854dfd94fc-5jd59 pod as shown below.

[root@localhost ~]# kubectl get pods | grep -i web-app
web-app-854dfd94fc-5jd59 1/1 Running 0 20s

Since it is a deployment so it is important to note here that if you try to delete the web-app-854dfd94fc-5jd59 pod it will recreate the same pod with different name. So to completely remove the pod you need to delete the deployment itself by using kubectl delete deployment web-app command as shown below.

[root@localhost ~]# kubectl delete deployment web-app
deployment.apps "web-app" deleted

Now if you check the status you will see pod is now in Terminating state.

[root@localhost ~]# kubectl get pods | grep -i web-app
web-app-854dfd94fc-5jd59 0/1 Terminating 0 58s

After sometime it will get terminated and now no pod is in running state.

[root@localhost ~]# kubectl get pods | grep -i web-app

 

 

 

 

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