Second Deploy

So far we have created the namespace without yaml.

See what a namespace would look like as a yaml

kubectl create namespace __NAME__ --dry-run -o yaml

store the minimal version as whoami/namespace.yml

apiVersion: v1
kind: Namespace
metadata:
  name: __NAME__

kubectl apply -f whoami

Notice how we omit replicas - it will then use the default value.

We also set metadata.namespace.

And apply the whole directory

whoami/deployment.yml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: whoami
  namespace: __NAME__
spec:
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami
    spec:
      containers:
        - name: whoami
          image: jwilder/whoami

Notice how we omit replicas - it will then use the default value.

We also set metadata.namespace.

And apply the whole directory

What's this mess?

spec:
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami

kubectl get pod -n __NAME__ -l app=whoami

kubectl label pod -n __NAME__ PODNAME test=yes

and get pods where test=yes

https://kubernetes.io/docs/concepts/scheduling-eviction/topology-spread-constraints/

apiVersion: apps/v1
kind: Deployment
metadata:
  name: whoami
  namespace: __NAME__
spec:
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami
    spec:
      topologySpreadConstraints:
        - maxSkew: 1
          topologyKey: kubernetes.io/zone
          whenUnsatisfiable: ScheduleAnyway
          labelSelector:
            matchLabels:
              app: whoami
      containers:
        - name: whoami
          image: jwilder/whoami

https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#nodeselector

https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#affinity-and-anti-affinity

You have reached the end of this section! Continue to the next section:

3. LoadBalancer