So, I am writing a custom auto-rescheduler for my clusters and I am using Python Client library to do so. As the rescheduler is still in proposal and nothing has been done for it, the only known way is to delete the pod from overused node and let the replication controller and scheduler take care of the rest (make a new pod and assign it to an appropriate node). What I want to know is can I use the client library to move the pods from one node to another without deleting the pod. Basically, I want to create a pod in an appropriate node first and then delete the pod in the over-used node. Is that possible?
Using node label you can start the container in matching nodes. for this first you need set the node label and update the deployment file and apply it.
Here is the sample yml file I used for blue green deployment, see this help.
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: webserver-blue
spec:
replicas: 2
template:
metadata:
labels:
type: webserver
color: blue
spec:
containers:
- image: nginx:1.12.0
name: webserver-container
ports:
- containerPort: 80
name: http-server
nodeSelector:
svrtype: webapiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: webserver-green
spec:
replicas: 2
template:
metadata:
labels:
type: webserver
color: green
spec:
containers:
- image: nginx:1.13.0
name: webserver-container
ports:
- containerPort: 80
name: http-server
nodeSelector:
svrtype: newwebAfter testing you can remove the old one. the issue here is you can direct the traffic to only one deployment at a time.