Menu
I'm just getting started with kubernetes and setting up a cluster on AWS using kops. In many of the examples I read (and try), there will be commands like:
kubectl run my-app --image=mycompany/myapp:latest --replicas=1 --port=8080 kubectl expose deployment my=app --port=80 --type=LoadBalancer This seems to do several things behind the scenes, and I can view the manifest files created using kubectl edit deployment, and so forth However, i see many examples where people are creating the manifest files by hand, and using commands like kubectl create -f or kubectl apply -f
Am I correct in assuming that both approaches accomplish the same goals, but that by creating the manifest files yourself, you have a finer grain of control?
Would I then have to be creating Service, ReplicationController, and Pod specs myself?
Lastly, if you create the manifest files yourself, how do people generally structure their projects as far as storing these files? Are they simply in a directory alongside the project they are deploying?
329
Creating Deployments You can create a Deployment using the kubectl apply , or kubectl create commands. Once created, the Deployment ensures that the desired number of Pods are running and available at all times. The Deployment automatically replaces Pods that fail or are evicted from their nodes.
kubectl run − Run command has the capability to run an image on the Kubernetes cluster. kubectl scale − It will scale the size of Kubernetes Deployments, ReplicaSet, Replication Controller, or job.
Kubectl apply apply manages applications through files defining Kubernetes resources. It creates and updates resources in a cluster through running kubectl apply . This is the recommended way of managing Kubernetes applications on production.
It's really important to remember that technically there isn't an inverse to kubectl apply . This is because of how k8s works, it converges desired state against current state. By running apply , you are telling the cluster to "make it look like this".
The fundamental question is how to apply all of the K8s objects into the k8s cluster. There are several ways to do this job.
All of the above ways have a different purpose and simplicity. For instance, If you want to check quickly whether the container is working as you desired then you might use Generators .
If you want to version control the k8s object then it's better to use declarative way which helps us to determine the accuracy of data in k8s objects.
Deployment, ReplicaSet and Pods are different layers which solve different problems.All of these concepts provide flexibility to k8s.
Lastly, It depends on use case how you want to use these concepts or methodology. It's not about which is good or which is bad.
199
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
