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antony@notes:~/kubernetes$ cat "Get-vs-List-in-K8s-RBAC.md"

"Get" vs "List" in K8s RBAC

2024-08-24· kubernetes

“Get” vs “List” in K8s RBAC

# 1. Create an app namespace
$ kubectl create ns app

# 2. Run a test Pods
$ kubectl -n app run nginx --image=nginx

# 3. Check Pods Status
$ kubectl -n app get pods
NAME    READY   STATUS    RESTARTS   AGE
nginx   1/1     Running   0          18m

# 4. Create a role which only can list Pods
$ kubectl -n app create role only-list --verb=get --resource=Pods

# 5. Create a rolebinding to bind "only-get" role with "only-get" user
$ kubectl -n app create rolebinding only-get --role=only-get --user=only-get

# 6. Use kubectl to list Pods
$ kubectl -n app get pods --as only-get
Error from server (Forbidden): pods is forbidden: User "only-get" cannot list resource "pods" in API group "" in the namespace "app"

# 7. Use kubectl to get Pods
$ kubectl -n app get pod nginx --as only-get
NAME    READY   STATUS    RESTARTS   AGE
nginx   1/1     Running   0          43m

# 8. View Get API Call
$ kubectl -v 10 2>&1 -n app get pod nginx --as only-list | grep 'curl -v -XGET' | tail -1
curl -v -XGET  ...省略'https://127.0.0.1:43213/api/v1/namespaces/app/pods/nginx'

# 9. Create a role which only can get Pods
$ kubectl -n app create role only-list --verb=list --resource=Pods

# 10. Create a rolebinding to bind "only-list" role with "only-list" user
$ kubectl -n app create rolebinding only-list --role=only-list --user=only-list

# 11. Use kubectl to list Pods
$ kubectl -n app get pod --as only-list
NAME    READY   STATUS    RESTARTS   AGE
nginx   1/1     Running   0          14m

# 12. Use kubectl to get Pods
$ kubectl -n app get pod nginx --as only-list
Error from server (Forbidden): pods "nginx" is forbidden: User "only-list" cannot get resource "pods" in API group "" in the namespace "app"

# 13. View List API Call
$ kubectl -v 10 2>&1 -n app get pods --as only-list | grep 'curl -v -XGET' | tail -1
curl -v -XGET  ...省略 'https://127.0.0.1:43213/api/v1/namespaces/app/pods?limit=500'