Running a workload on Spot

Next, let's modify our sample retail store application to run the catalog component on the newly created Spot instances. To do so, we'll utilize Kustomize to apply a patch to the catalog Deployment, adding a nodeSelector field with eks.amazonaws.com/capacityType: SPOT.

Kustomize Patch

~/environment/eks-workshop/modules/fundamentals/mng/spot/deployment/deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: catalog
spec:
  template:
    spec:
      nodeSelector:
        eks.amazonaws.com/capacityType: SPOT

Deployment/catalog

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app.kubernetes.io/created-by: eks-workshop
    app.kubernetes.io/type: app
  name: catalog
  namespace: catalog
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/component: service
      app.kubernetes.io/instance: catalog
      app.kubernetes.io/name: catalog
  template:
    metadata:
      annotations:
        prometheus.io/path: /metrics
        prometheus.io/port: "8080"
        prometheus.io/scrape: "true"
      labels:
        app.kubernetes.io/component: service
        app.kubernetes.io/created-by: eks-workshop
        app.kubernetes.io/instance: catalog
        app.kubernetes.io/name: catalog
    spec:
      containers:
        - env:
            - name: DB_USER
              valueFrom:
                secretKeyRef:
                  key: username
                  name: catalog-db
            - name: DB_PASSWORD
              valueFrom:
                secretKeyRef:
                  key: password
                  name: catalog-db
          envFrom:
            - configMapRef:
                name: catalog
          image: public.ecr.aws/aws-containers/retail-store-sample-catalog:0.4.0
          imagePullPolicy: IfNotPresent
          livenessProbe:
            httpGet:
              path: /health
              port: 8080
            initialDelaySeconds: 30
            periodSeconds: 3
          name: catalog
          ports:
            - containerPort: 8080
              name: http
              protocol: TCP
          readinessProbe:
            httpGet:
              path: /health
              port: 8080
            periodSeconds: 5
            successThreshold: 3
          resources:
            limits:
              memory: 512Mi
            requests:
              cpu: 250m
              memory: 512Mi
          securityContext:
            capabilities:
              drop:
                - ALL
            readOnlyRootFilesystem: true
            runAsNonRoot: true
            runAsUser: 1000
          volumeMounts:
            - mountPath: /tmp
              name: tmp-volume
      nodeSelector:
        eks.amazonaws.com/capacityType: SPOT
      securityContext:
        fsGroup: 1000
      serviceAccountName: catalog
      volumes:
        - emptyDir:
            medium: Memory
          name: tmp-volume

Diff

             runAsUser: 1000
           volumeMounts:
             - mountPath: /tmp
               name: tmp-volume
+      nodeSelector:
+        eks.amazonaws.com/capacityType: SPOT
       securityContext:
         fsGroup: 1000
       serviceAccountName: catalog
       volumes:

Apply the Kustomize patch with the following command.

~$kubectl apply -k ~/environment/eks-workshop/modules/fundamentals/mng/spot/deployment

namespace/catalog unchanged

serviceaccount/catalog unchanged

configmap/catalog unchanged

secret/catalog-db unchanged

service/catalog unchanged

service/catalog-mysql unchanged

deployment.apps/catalog configured

statefulset.apps/catalog-mysql unchanged

Ensure the successful deployment of your app with the following command.

~$kubectl rollout status deployment/catalog -n catalog --timeout=5m

Finally, let's verify that the catalog pods are running on Spot instances. Run the following two commands.

~$kubectl get pods -l app.kubernetes.io/component=service -n catalog -o wide

NAME                       READY   STATUS    RESTARTS   AGE     IP              NODE

catalog-6bf46b9654-9klmd   1/1     Running   0          7m13s   10.42.118.208   ip-10-42-99-254.us-east-2.compute.internal

~$kubectl get nodes -l eks.amazonaws.com/capacityType=SPOT

NAME                                          STATUS   ROLES    AGE   VERSION

ip-10-42-139-140.us-east-2.compute.internal   Ready    <none>   16m   v1.29-eks-48e63af

ip-10-42-99-254.us-east-2.compute.internal    Ready    <none>   16m   v1.29-eks-48e63af

The first command tells us that the catalog pod is running on node ip-10-42-99-254.us-east-2.compute.internal, which we verify is a Spot instance by matching it to the output of the second command.

In this lab, you deployed a managed node group that creates Spot instances, and then modified the catalog deployment to run on the newly created Spot instances. Following this process, you can modify any of the running deployments in the cluster by adding the nodeSelector parameter, as specified in the Kustomization patch above.