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This article mainly explains "how to verify deployment in kubernetes". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "how to verify deployment in kubernetes".

K8s usually does not create pod directly, but manages pod through controller to achieve replica management, rolling upgrade, and cluster-level self-healing capabilities. Controller includes Deployment, ReplicaSet, DaemonSet, StatefuleSet, Job, etc.

The pod created by 1.kubectl run has no self-healing function because the pod is not managed by controller.

2.Deployment is the most commonly used controller for deploying stateless services to manage replicaset and update pod

3. Once the Deployment is created, Deployment contorller will immediately create a replica set of ReplicaSet, and ReplicaSet will create the required pod. When you update deployment, the deployment controller creates a new ReplicaSet replica set for deployment and gradually creates pod; in the new replica set to remove pod from the old replica set, achieving the effect of rolling updates.

4. The release update of the Deployment is triggered when and only if the content of the Depoyment's Pod template field changes.

Create deployment

# run directly from the command line

Kubectl create deployment nginx-image=nginx

# create via configuration file yaml

Kubectl create deployment nginx-- image=nginx-- dry-run='client'-o yaml > dep.yaml

Kubectl apply-f dep.yaml

# Delete deployment

Kubectl delete deployment nginx

Kubectl delete-f dep.yaml

# verify that pod managed by deployment is self-healing

Kubectl run has a pod and kubectl create deployment has a pod managed by controller.

Kubectl get pods-o wide checks the node of pod distribution

Kubectl drain node2 expels pod distributed on node2

Kubectl get pods-o wide can see that node2 scheduling is disabled, and controller-managed pod is migrated to node1 running, while kubectl run's pod has been deleted

Kubectl get rs can see the corresponding replicaset controller.

# View the specific configuration of deployment

Kubectl edit deployment nginx

# expand pod to 2

Kubectl scale deployment nginx-replicas=2

# View the rolling update status of deployment nginx

Kubectl rollout status deployment nginx

# View deployments

Kubectl get deployments

# View replicasets

Kubectl get rs-w

# View the events of deployment

Kubectl describe deployment

# View update history

Kubectl rollout history deployment nginx

# rollback to the previous version, you cannot rollback a paused Deployment unless you continue (resume) the Deployment

Kubectl rollout undo deployment nginx

Kubectl rollout undo deployment nginx-to-revision=2

# pause updates

Kubectl rollout pause deployment nginx

# resume updates

Kubectl rollout resume deployment nginx

# Export the configuration file of deployment

Kubectl get deployment deploy_name-o yaml > deployment.yaml

# when deleting a ReplicaSet, its dependent objects will not be deleted

Kubectl delete replicaset my-repset-cascade=false

Exposing pod Services with service

Kubectl expose deployment nginx-port=80-type=NodePort

# View service

Kubectl get svc

# check the endpoint corresponding to service

Kubectl get endpoints

# Verification

Curl http://service-clusterIP

Curl http://nodeIP:32038

For the nginx run on the above command line, you can use the following configuration file to cloud

Vi nginx-dep-service.yaml

ApiVersion: apps/v1

Kind: Deployment

Metadata:

Name: web-nginx

Labels:

App: nginx

Spec:

Replicas: 1

Selector:

MatchLabels:

App: nginx

Template:

Metadata:

Labels:

App: nginx

Spec:

Containers:

-name: nginx

Image: nginx

--

ApiVersion: v1

Kind: Service

Metadata:

Name: web-nginx

Labels:

Apps: nginx

Spec:

Selector:

App: nginx

Ports:

-name: web-nginx

Protocol: TCP

Port: 80

NodePort: 32600

TargetPort: 80

Type: NodePort

Kubectl apply-f nginx-dep-service.yaml

Thank you for reading, the above is the content of "how to verify deployment in kubernetes", after the study of this article, I believe you have a deeper understanding of how to verify deployment in kubernetes, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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