apiVersion: v1
kind: ConfigMap
metadata:
  name: check-readahead-settings
  namespace: default
data:
  show-readahead.sh: |
    #!/bin/bash
    echo "### $(date) - show-readahead.sh - looking for NFS filemounts on this host"
    cat /proc/self/mountinfo | grep nfs4 | awk {'print $3, $5'} | uniq | while read bdev vmount
    do
      echo "$vmount $bdev /sys/class/bdi/$bdev/read_ahead_kb = "$(cat /sys/class/bdi/$bdev/read_ahead_kb)
    done
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: check-readahead-settings
  namespace: default
spec:
  selector:
    matchLabels:
      name: check-readahead-settings
  template:
    metadata:
      labels:
        name: check-readahead-settings
    spec:
      volumes:
      - name: config-volume
        configMap:
          name: check-readahead-settings
      - name: host-mount
        hostPath:
          path: /tmp
      containers:
      - command:
        - /bin/sh
        - -c
        - |
          #!/bin/sh
          cp /tmp/show-readahead.sh /host/show-readahead.sh
          chmod 777 /host/show-readahead.sh
          while true; do
            /usr/bin/nsenter -m/proc/1/ns/mnt -- /tmp/show-readahead.sh
            sleep 30
          done
        image: alpine
        imagePullPolicy: Always
        name: check-readahead-settings
        volumeMounts:
        - name: config-volume
          mountPath: /tmp
        - name: host-mount
          mountPath: /host
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 200Mi
        securityContext:
          privileged: true
        stdin: true
        stdinOnce: true
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        tty: true
      nodeSelector:
        kubernetes.io/os: linux
        kubernetes.azure.com/mode: user
      tolerations:
      - key: workload.sas.com/class
        operator: Equal
        value: compute
        effect: NoSchedule
      - key: workload.sas.com/class
        operator: Equal
        value: connect
        effect: NoSchedule
      - key: workload.sas.com/class
        operator: Equal
        value: cas
        effect: NoSchedule
      priorityClassName: system-node-critical
      dnsPolicy: ClusterFirst
      enableServiceLinks: true
      hostPID: true