以前，我们会在kubelet上加–allow-prividged启动参数来实现。
而现在，更推荐的是用pod secureity policy来实现。前面的那种方式以后会被废弃。
https://kubernetes.io/docs/concepts/policy/pod-security-policy/
https://docs.projectcalico.org/v3.6/getting-started/kubernetes/requirements
Privileges
Ensure that Calico has the CAP_SYS_ADMIN privilege.
The simplest way to provide the necessary privilege is to run Calico as root or in a privileged container. When installed as a Kubernetes daemon set, Calico meets this requirement by running as a privileged container. This requires that the kubelet be allowed to run privileged containers. There are two ways this can be achieved.
- Specify
--allow-privilegedon the kubelet (deprecated). - Use a pod security policy.
apiVersion: policy/v1beta1kind: PodSecurityPolicymetadata: name: privileged annotations: seccomp.security.alpha.kubernetes.io/allowedProfileNames: '*'spec: privileged: true allowPrivilegeEscalation: true allowedCapabilities: - '*' volumes: - '*' hostNetwork: true hostPorts: - min: 0 max: 65535 hostIPC: true hostPID: true runAsUser: rule: 'RunAsAny' seLinux: rule: 'RunAsAny' supplementalGroups: rule: 'RunAsAny' fsGroup: rule: 'RunAsAny'
比如，在新版flannel中，相关的配置就已发生了更改，可以对比一起实现差异。
现在的flannel.yaml
---apiVersion: extensions/v1beta1kind: PodSecurityPolicymetadata: name: psp.flannel.unprivileged annotations: seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/defaultspec: privileged: false volumes: - configMap - secret - emptyDir - hostPath allowedHostPaths: - pathPrefix: "/etc/cni/net.d" - pathPrefix: "/etc/kube-flannel" - pathPrefix: "/run/flannel" readOnlyRootFilesystem: false # Users and groups runAsUser: rule: RunAsAny supplementalGroups: rule: RunAsAny fsGroup: rule: RunAsAny # Privilege Escalation allowPrivilegeEscalation: false defaultAllowPrivilegeEscalation: false # Capabilities allowedCapabilities: ['NET_ADMIN'] defaultAddCapabilities: [] requiredDropCapabilities: [] # Host namespaces hostPID: false hostIPC: false hostNetwork: true hostPorts: - min: 0 max: 65535 # SELinux seLinux: # SELinux is unsed in CaaSP rule: 'RunAsAny'---kind: ClusterRoleapiVersion: rbac.authorization.k8s.io/v1beta1metadata: name: flannelrules: - apiGroups: ['extensions'] resources: ['podsecuritypolicies'] verbs: ['use'] resourceNames: ['psp.flannel.unprivileged'] - apiGroups: - "" resources: - pods verbs: - get - apiGroups: - "" resources: - nodes verbs: - list - watch - apiGroups: - "" resources: - nodes/status verbs: - patch---kind: ClusterRoleBindingapiVersion: rbac.authorization.k8s.io/v1beta1metadata: name: flannelroleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: flannelsubjects:- kind: ServiceAccount name: flannel namespace: kube-system---apiVersion: v1kind: ServiceAccountmetadata: name: flannel namespace: kube-system---kind: ConfigMapapiVersion: v1metadata: name: kube-flannel-cfg namespace: kube-system labels: tier: node app: flanneldata: cni-conf.json: | { "name": "cbr0", "plugins": [ { "type": "flannel", "delegate": { "hairpinMode": true, "isDefaultGateway": true } }, { "type": "portmap", "capabilities": { "portMappings": true } } ] } net-conf.json: | { "Network": "10.244.0.0/16", "Backend": { "Type": "vxlan" } }---apiVersion: extensions/v1beta1kind: DaemonSetmetadata: name: kube-flannel-ds-amd64 namespace: kube-system labels: tier: node app: flannelspec: template: metadata: labels: tier: node app: flannel spec: hostNetwork: true nodeSelector: beta.kubernetes.io/arch: amd64 tolerations: - operator: Exists effect: NoSchedule serviceAccountName: flannel initContainers: - name: install-cni image: quay.io/coreos/flannel:v0.11.0-amd64 command: - cp args: - -f - /etc/kube-flannel/cni-conf.json - /etc/cni/net.d/10-flannel.conflist volumeMounts: - name: cni mountPath: /etc/cni/net.d - name: flannel-cfg mountPath: /etc/kube-flannel/ containers: - name: kube-flannel image: quay.io/coreos/flannel:v0.11.0-amd64 command: - /opt/bin/flanneld args: - --ip-masq - --kube-subnet-mgr resources: requests: cpu: "100m" memory: "50Mi" limits: cpu: "100m" memory: "50Mi" securityContext: privileged: false capabilities: add: ["NET_ADMIN"] env: - name: POD_NAME valueFrom: fieldRef: fieldPath: metadata.name - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace volumeMounts: - name: run mountPath: /run/flannel - name: flannel-cfg mountPath: /etc/kube-flannel/ volumes: - name: run hostPath: path: /run/flannel - name: cni hostPath: path: /etc/cni/net.d - name: flannel-cfg configMap: name: kube-flannel-cfg
