Adding 'affinity' support to run 'descheduler' in CronJob or Deployment

[martin-magakian]

I want to add 'affinity' support in order to fine tune where 'descheduler' should run.

My current use case: I want to prefer "spot" instances over "ondemand" instances

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[k8s-ci-robot]

Hi @martin-magakian. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ Martin Magakian (ad20777)

[martin-magakian]

signed

[damemi]

sounds reasonable to me, affinity provides more expressive functionality than nodeSelector which we already have.

@martin-magakian could you please link to the issue for this PR in your description? (#659) Adding Fixes #659 will auto-close the issue when this merges

[damemi]

/ok-to-test

[ingvagabund]

@martin-magakian can you also add the new param into https://github.com/kubernetes-sigs/descheduler/blob/master/charts/descheduler/README.md ?

[ingvagabund]

Looks good otherwise:

$ helm version
version.BuildInfo{Version:"v3.7.2", GitCommit:"663a896f4a815053445eec4153677ddc24a0a361", GitTreeState:"clean", GoVersion:"go1.16.10"}
$ helm install --dry-run --debug ./charts/descheduler --generate-name -f ./charts/descheduler/values.yaml:
...
# Source: descheduler/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: descheduler-1639752774
  labels:
    app.kubernetes.io/name: descheduler
    helm.sh/chart: descheduler-0.22.0
    app.kubernetes.io/instance: descheduler-1639752774
    app.kubernetes.io/version: "0.22.0"
    app.kubernetes.io/managed-by: Helm
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: descheduler
      app.kubernetes.io/instance: descheduler-1639752774
  template:
    metadata:
      labels:
        app.kubernetes.io/name: descheduler
        app.kubernetes.io/instance: descheduler-1639752774
      annotations:
        checksum/config: 53d6ea8862d3b963e992a2024d5239a9afc09c446e8185ecd444196f04141aec
    spec:
      priorityClassName: system-cluster-critical
      serviceAccountName: descheduler-1639752774
      containers:
        - name: descheduler
          image: "k8s.gcr.io/descheduler/descheduler:v0.22.0"
          imagePullPolicy: IfNotPresent
          command:
            - "/bin/descheduler"
          args:
            - "--policy-config-file"
            - "/policy-dir/policy.yaml"
            - "--descheduling-interval"
            - 5m
            - "--v"
            - "3"
          ports:
            - containerPort: 10258
              protocol: TCP
          resources:
            requests:
              cpu: 500m
              memory: 256Mi
          securityContext:
            allowPrivilegeEscalation: false
            capabilities:
              drop:
                - ALL
            privileged: false
            readOnlyRootFilesystem: true
            runAsNonRoot: true
          volumeMounts:
            - mountPath: /policy-dir
              name: policy-volume
      volumes:
        - name: policy-volume
          configMap:
            name: descheduler-1639752774
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/e2e-az-name
                operator: In
                values:
                - e2e-az1
                - e2e-az2

[ingvagabund]

/approve
/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ingvagabund, martin-magakian

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