Unable to install kubebench on GKE

[ajinkya1986]

Overview

We are trying to install kube-bench on GKE. But we are getting read only file system error for /srv/kubernetes and /opt/cni volume mount directories. So instead of using the directory we are using emptyDir. How and what will be the effect if we use emptyDir

Following is the cronjob

apiVersion: batch/v1
{{- else }}
apiVersion: batch/v1beta1
{{- end }}
kind: CronJob
metadata:
  name: {{ .Values.misconfigCron.name }}
  namespace: ajinkya
  labels:
    {{- with .Values.misconfigCron.labels }}
    {{ toYaml . | indent 8 }}
    {{- end }}
spec:
  schedule: {{ .Values.misconfigCron.schedule | quote }}
  jobTemplate:
    spec:
      template:
        metadata:
          labels:
            app: kube-bench
        spec:
          hostPID: true
          restartPolicy: Never
          containers:
          - name: misconfig-cron
            image: {{ .Values.misconfigCron.image }}
            imagePullPolicy: IfNotPresent
            # terminationGracePeriodSeconds: 60
            command: ["kube-bench", "--httpoutput=true"]
            # command: ["kube-bench", "--include-test-output", "--noremediations", "--noresults", "--nototals", "--httpoutput=true"]
            env:
            - name: TOKEN
              valueFrom:
                secretKeyRef:
                  name: testing-secrets
                  key: auth-token
            - name: NODE_NAME
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            volumeMounts:
            - name: var-lib-etcd
              mountPath: /var/lib/etcd
              readOnly: true
            - name: var-lib-kubelet
              mountPath: /var/lib/kubelet
              readOnly: true
            - name: var-lib-kube-scheduler
              mountPath: /var/lib/kube-scheduler
              readOnly: true
            - name: var-lib-kube-controller-manager
              mountPath: /var/lib/kube-controller-manager
              readOnly: true
            - name: etc-systemd
              mountPath: /etc/systemd
              readOnly: true
            - name: lib-systemd
              mountPath: /lib/systemd/
              readOnly: true
            - name: srv-kubernetes
              mountPath: /srv/kubernetes/
              readOnly: true
            - name: etc-kubernetes
              mountPath: /etc/kubernetes
              readOnly: true
              # /usr/local/mount-from-host/bin is mounted to access kubectl / kubelet, for auto-detecting the Kubernetes version.
              # You can omit this mount if you specify --version as part of the command.
            - name: usr-bin
              mountPath: /usr/local/mount-from-host/bin
              readOnly: true
            - name: etc-cni-netd
              mountPath: /etc/cni/net.d/
              readOnly: true
            - name: opt-cni-bin
              mountPath: /opt/cni/bin/
              readOnly: true
            - name: var-tmp-dump
              mountPath: /var/tmp/dump
            - name: misconfig-volume
              mountPath: /etc/config.yaml
              subPath: config.yaml
          volumes:
          - name: var-lib-etcd
            hostPath:
              path: "/var/lib/etcd"
          - name: var-lib-kubelet
            hostPath:
              path: "/var/lib/kubelet"
          - name: var-lib-kube-scheduler
            hostPath:
              path: "/var/lib/kube-scheduler"
          - name: var-lib-kube-controller-manager
            hostPath:
              path: "/var/lib/kube-controller-manager"
          - name: etc-systemd
            hostPath:
              path: "/etc/systemd"
          - name: lib-systemd
            hostPath:
              path: "/lib/systemd"
          - name: srv-kubernetes
            emptyDir: {}
          - name: etc-kubernetes
            hostPath:
              path: "/etc/kubernetes"
          - name: usr-bin
            hostPath:
              path: "/usr/bin"
          - name: etc-cni-netd
            hostPath:
              path: "/etc/cni/net.d/"
          - name: opt-cni-bin
            emptyDir: {}
          - name: var-tmp-dump
            hostPath:
              path: "/var/tmp/dump"
          - name: misconfig-volume
            configMap:
              name: {{ .Values.misconfigCron.configMapName }}
---

After installing the helm chart one of our misconfigcron job failed due to read only file system error. Following is the error. (combined from similar events): Error: failed to generate container "25441f585d69c59f163d51ddf295dd257e27392e79b3f2729" spec: failed to generate spec: failed to mkdir "/srv/kubernetes": mkdir /srv/kubernetes: read-only file system

[vaboston]

Hello, you can add this to run on GKE :

             volumeMounts:
            - name: srv-kubernetes
              mountPath: /tmp/kubernetes/
              readOnly: true
 [...]
        volumes:
        - name: srv-kubernetes
          hostPath:
            path: "/tmp/kubernetes"