02-Manual-Scheduling.md

Manual Scheduling

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In this section, we will take a look at Manually Scheduling a POD on a node.

How Scheduling Works

• What do you do when you do not have a scheduler in your cluster?
  • Every POD has a field called NodeName that by default is not set. You don't typically specify this field when you create the manifest file, kubernetes adds it automatically.
  • Once identified it schedules the POD on the node by setting the nodeName property to the name of the node by creating a binding object.

    apiVersion: v1
    kind: Pod
    metadata:
     name: nginx
     labels:
      name: nginx
    spec:
     containers:
     - name: nginx
       image: nginx
       ports:
       - containerPort: 8080
     nodeName: node02
    

    

No Scheduler

• You can manually assign pods to node itself. Well without a scheduler, to schedule pod is to set nodeName property in your pod definition file while creating a pod.

  

• Another way

  apiVersion: v1
  kind: Binding
  metadata:
    name: nginx
  target:
    apiVersion: v1
    kind: Node
    name: node02
  

  apiVersion: v1
  kind: Pod
  metadata:
   name: nginx
   labels:
    name: nginx
  spec:
   containers:
   - name: nginx
     image: nginx
     ports:
     - containerPort: 8080
  

  

K8s Reference Docs:

• https://kubernetes.io/docs/reference/using-api/api-concepts/
• https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#nodename