$ k get ns qa --show-labels
NAME STATUS AGE LABELS
qa Active 47m env=stage
$ k get pods -n dev --show-labels
NAME READY STATUS RESTARTS AGE LABELS
product 1/1 Running 0 3s env=dev-team
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: restricted-policy
namespace: dev
spec:
podSelector:
matchLabels:
env: dev-team
policyTypes:
- Ingress
ingress:
- from:
- namespaceSelector:
matchLabels:
env: stage
- podSelector:
matchLabels:
env: stage
[desk@cli] $ k get ns qa --show-labels
NAME STATUS AGE LABELS
qa Active 47m env=stage
[desk@cli] $ k get pods -n dev --show-labels
NAME READY STATUS RESTARTS AGE LABELS
product 1/1 Running 0 3s env=dev-team
[desk@cli] $ vim netpol2.yaml
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
name: restricted-policy
namespace: dev
spec:
podSelector:
matchLabels:
env: dev-team
policyTypes:
- Ingress
ingress:
- from:
- namespaceSelector:
matchLabels:
env: stage
- podSelector:
matchLabels:
env: stage
[desk@cli] $ k apply -f netpol2.yaml Reference: https://kubernetes.io/docs/concepts/services-networking/network-policies/
[desk@cli] $ k apply -f netpol2.yaml Reference: https://kubernetes.io/docs/concepts/services-networking/network-policies/

[desk@cli] $ k create sa backend-qa -n qa sa/backend-qa created [desk@cli] $ k get role,rolebinding -n qa No resources found in qa namespace. [desk@cli] $ k create role backend -n qa --resource pods,namespaces,configmaps --verb list # No access to secret [desk@cli] $ k create rolebinding backend -n qa --role backend --serviceaccount qa:backend-qa [desk@cli] $ vim /home/cert_masters/frontend-pod.yaml apiVersion: v1 kind: Pod metadata:
name: frontend
spec:
serviceAccountName: backend-qa # Add this
image: nginx
name: frontend
[desk@cli] $ k apply -f /home/cert_masters/frontend-pod.yaml pod created
[desk@cli] $ k create sa backend-qa -n qa serviceaccount/backend-qa created [desk@cli] $ k get role,rolebinding -n qa No resources found in qa namespace. [desk@cli] $ k create role backend -n qa --resource pods,namespaces,configmaps --verb list role.rbac.authorization.k8s.io/backend created [desk@cli] $ k create rolebinding backend -n qa --role backend --serviceaccount qa:backend-qa rolebinding.rbac.authorization.k8s.io/backend created [desk@cli] $ vim /home/cert_masters/frontend-pod.yaml apiVersion: v1 kind: Pod metadata:
name: frontend
spec:
serviceAccountName: backend-qa # Add this
image: nginx
name: frontend
[desk@cli] $ k apply -f /home/cert_masters/frontend-pod.yaml pod/frontend created https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/

Create a PSP that will prevent the creation of privileged pods in the namespace.
$ cat clusterrole-use-privileged.yaml
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: use-privileged-psp
rules:
- apiGroups: ['policy']
resources: ['podsecuritypolicies']
verbs: ['use']
resourceNames:
- default-psp
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
name: privileged-role-bind
namespace: psp-test
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: use-privileged-psp
subjects:
- kind: ServiceAccount
name: privileged-sa
$ kubectl -n psp-test apply -f clusterrole-use-privileged.yaml
After a few moments, the privileged Pod should be created.
Create a new PodSecurityPolicy named prevent-privileged-policy which prevents the creation of privileged pods.
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
name: example
spec:
privileged: false # Don't allow privileged pods!
# The rest fills in some required fields.
seLinux:
rule: RunAsAny
supplementalGroups:
rule: RunAsAny
runAsUser:
rule: RunAsAny
fsGroup:
rule: RunAsAny
volumes:
- '*'
And create it with kubectl:
kubectl-admin create -f example-psp.yaml
Now, as the unprivileged user, try to create a simple pod:
kubectl-user create -f- <<EOF
apiVersion: v1
kind: Pod
metadata:
name: pause
spec:
containers:
- name: pause
image: k8s.gcr.io/pause
EOF
The output is similar to this:
Error from server (Forbidden): error when creating "STDIN": pods "pause" is forbidden: unable to validate against any pod security policy: [] Create a new ServiceAccount named psp-sa in the namespace default.
$ cat clusterrole-use-privileged.yaml
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: use-privileged-psp
rules:
- apiGroups: ['policy']
resources: ['podsecuritypolicies']
verbs: ['use']
resourceNames:
- default-psp
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
name: privileged-role-bind
namespace: psp-test
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: use-privileged-psp
subjects:
- kind: ServiceAccount
name: privileged-sa
$ kubectl -n psp-test apply -f clusterrole-use-privileged.yaml
After a few moments, the privileged Pod should be created.
Create a new ClusterRole named prevent-role, which uses the newly created Pod Security Policy prevent-privileged-policy.
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
name: example
spec:
privileged: false # Don't allow privileged pods!
# The rest fills in some required fields.
seLinux:
rule: RunAsAny
supplementalGroups:
rule: RunAsAny
runAsUser:
rule: RunAsAny
fsGroup:
rule: RunAsAny
volumes:
- '*'
And create it with kubectl:
kubectl-admin create -f example-psp.yaml
Now, as the unprivileged user, try to create a simple pod:
kubectl-user create -f- <<EOF
apiVersion: v1
kind: Pod
metadata:
name: pause
spec:
containers:
- name: pause
image: k8s.gcr.io/pause
EOF
The output is similar to this:
Error from server (Forbidden): error when creating "STDIN": pods "pause" is forbidden: unable to validate against any pod security policy: [] Create a new ClusterRoleBinding named prevent-role-binding, which binds the created ClusterRole prevent-role to the created SA psp-sa.
apiVersion: rbac.authorization.k8s.io/v1
# This role binding allows "jane" to read pods in the "default" namespace.
# You need to already have a Role named "pod-reader" in that namespace.
kind: RoleBinding
metadata:
name: read-pods
namespace: default
subjects:
# You can specify more than one "subject"
- kind: User
name: jane # "name" is case sensitive
apiGroup: rbac.authorization.k8s.io
roleRef:
# "roleRef" specifies the binding to a Role / ClusterRole
kind: Role #this must be Role or ClusterRole
name: pod-reader # this must match the name of the Role or ClusterRole you wish to bind to apiGroup: rbac.authorization.k8s.io apiVersion: rbac.authorization.k8s.io/v1 kind: Role metadata:
namespace: default
name: pod-reader
rules:
- apiGroups: [""] # "" indicates the core API group
resources: ["pods"]
verbs: ["get", "watch", "list"]