NFS Stale Handle Liveness Probe

example-nginx-deployment.yaml

---
apiVersion: v1
data:
  liveness.sh: |
    #!/bin/bash
    
    # Get list of nfs mounts
    temp_file=$(mktemp)
    # May need to change to nfs depending on base image
    mount -t nfs4 > "$temp_file"
    
    # Check every nfs mount
    while read -r _ _ mount _; do
      echo "Checking $mount"
      if ! stat "$mount" > /dev/null 2>&1; then
        # If a mount is inaccessible, exit 1 to fail the probe
        echo "$mount is stale or not accessible"
        exit 1
      fi
    done < "$temp_file"
    rm "$temp_file"
    exit 0
kind: ConfigMap
metadata:
  creationTimestamp: null
  name: liveness
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx
  name: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  strategy: {}
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:latest
        name: nginx
        volumeMounts:
        - name: html-root
          mountPath: /usr/share/nginx/html
        - name: liveness
          mountPath: /usr/bin/liveness.sh
          subPath: liveness.sh
        resources: {}
        ports:
        - containerPort: 80
        livenessProbe:
          exec:
            command:
            - /bin/sh
            - /usr/bin/liveness.sh
          initialDelaySeconds: 30
          periodSeconds: 60
          timeoutSeconds: 5
      volumes:
      - name: html-root
        nfs:
          server: 192.168.1.200
          path: /opt/nfs/nginx
          readOnly: true
      - name: liveness
        configMap:
          name: liveness
status: {}

liveness.sh

#!/bin/bash

# Get list of nfs mounts
temp_file=$(mktemp)
# May need to change to nfs depending on base image
mount -t nfs4 > "$temp_file"

# Check every nfs mount
while read -r _ _ mount _; do 
  echo "Checking $mount"
  if ! stat "$mount" > /dev/null 2>&1; then
    # If a mount is inaccessible, exit 1 to fail the probe
    echo "$mount is stale or not accessible"
    exit 1
  fi
done < "$temp_file"
rm "$temp_file"
exit 0