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kubernetes exam in action
  • kubernetes exam in action
  • 云原生
  • KCNA 考试
    • KCNA 1:云原生架构
    • KCNA 2:容器编排
    • KCNA 3:kubernetes基础知识
    • KCNA 4:kubernetes实践
    • KCNA 5:持续交付
    • KCNA 6:监控与探测
    • KCNA 7:测试题
  • CKA考试
    • CKA、CKAD考试经验
    • CKA试题
  • CKAD考试
    • 1. Core Concepts (13%)
    • 2. Configuration (18%)
    • 3. Multi-Container Pods (10%)
    • 4. Observability (18%)
    • 5. Pod Design (20%)
    • 6. Networking (13%)
    • 7. State Persistence (8%)
    • 8. 考试小技巧
  • CKS考试
    • cks 试题
    • RBAC
    • Dashboard
    • Secure Ingress
    • Node Metadata
    • CIS Benchmarks
    • Verify Platform
    • Networkpolicy
    • Restrict API Access
    • ServiceAccounts
    • Upgrade Kubernetes
    • Secrets 安全
    • Container Runtime Sandboxes
    • securityContext and podsecurityPolicies
    • SecurityContext and StartupProbe
    • Open Policy Agent (OPA)
    • Image build
    • Image Vulnerability Scanning(Trivy)
    • ImagePolicyWebhook
    • Static Analysis(OPA)
    • /proc and Env
    • Auditing
    • Apparmor
    • Falco
    • Strace
由 GitBook 提供支持
在本页
  • 1. 介绍
  • 2. Anonymous Access
  • 3. Insecure Access
  • 4. Manual API Request
  • 5. External Apiserver Access
  • 6. NodeRestriction AdmissionController
  • 7. Verify NodeRestriction
  1. CKS考试

Restrict API Access

上一页Networkpolicy下一页ServiceAccounts

最后更新于3年前

1. 介绍

2. Anonymous Access

\

root@master:~/cks/serviceaccount# curl https://localhost:6443
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: https://curl.haxx.se/docs/sslcerts.html

curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.
root@master:~/cks/serviceaccount# curl https://localhost:6443 -k
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {
    
  },
  "status": "Failure",
  "message": "forbidden: User \"system:anonymous\" cannot get path \"/\"",
  "reason": "Forbidden",
  "details": {
    
  },
  "code": 403
}root@master:~/cks/serviceaccount# vim /etc/kubernetes/manifests/kube-apiserver.yaml 
...
    - kube-apiserver
    - --anonymous-auth=false
    - --advertise-address=192.168.211.40
....
root@master:~/cks/serviceaccount# k get pods | grep api
The connection to the server 192.168.211.40:6443 was refused - did you specify the right host or port?
root@master:~/images# k get pods -n kube-system | grep api
kube-apiserver-master                      1/1     Running   0          8m3s
root@master:~/images# k get pods -n kube-system | grep api
kube-apiserver-master                      1/1     Running   0          3s
root@master:~/cks/serviceaccount# vim /etc/kubernetes/manifests/kube-apiserver.yaml 
...
    - kube-apiserver
    - --anonymous-auth=true #默认其实为true
    - --advertise-address=192.168.211.40
....


root@master:~/cks/serviceaccount# curl https://localhost:6443 -k
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {
    
  },
  "status": "Failure",
  "message": "forbidden: User \"system:anonymous\" cannot get path \"/\"",
  "reason": "Forbidden",
  "details": {
    
  },
  "code": 403
}

3. Insecure Access

\

root@master:~/cks/serviceaccount# curl https://localhost:6443 -k
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {
    
  },
  "status": "Failure",
  "message": "forbidden: User \"system:anonymous\" cannot get path \"/\"",
  "reason": "Forbidden",
  "details": {
    
  },
  "code": 403
}

root@master:~# vim /etc/kubernetes/manifests/kube-apiserver.yaml
...
    - kube-apiserver
    - --advertise-address=192.168.211.40
    - --allow-privileged=true
    - --authorization-mode=Node,RBAC
    - --client-ca-file=/etc/kubernetes/pki/ca.crt
    - --enable-admission-plugins=NodeRestriction
    - --enable-bootstrap-token-auth=true
    - --etcd-cafile=/etc/kubernetes/pki/etcd/ca.crt
    - --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt
    - --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key
    - --etcd-servers=https://127.0.0.1:2379
    - --insecure-port=8080  #0改成8080
  .....


root@master:~/cks/serviceaccount# k get pods | grep api
The connection to the server 192.168.211.40:6443 was refused - did you specify the right host or port?

root@master:~/images# k get pods -n kube-system | grep api
kube-apiserver-master                      1/1     Running   0          3s


root@master:~# curl http://localhost:8080

4. Manual API Request

root@master:/etc/kubernetes/pki# curl https://192.168.211.40:6443 --cacert ca --cert  ca.crt --key ca.key

5. External Apiserver Access

root@master:/etc/kubernetes/pki# k edit svc
....
  type: NodePort
....

root@master:/etc/kubernetes/pki# k get svc
NAME         TYPE       CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
kubernetes   NodePort   10.96.0.1    <none>        443:30300/TCP   19h



root@master:/etc/kubernetes/pki# curl https://192.168.211.40:30300 -l
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: https://curl.haxx.se/docs/sslcerts.html

curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.
root@master:/etc/kubernetes/pki# curl https://192.168.211.40:30300 -k
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {
    
  },
  "status": "Failure",
  "message": "forbidden: User \"system:anonymous\" cannot get path \"/\"",
  "reason": "Forbidden",
  "details": {
    
  },
  "code": 403
}
root@master:~/cks/apiserver# k config view --raw >config
root@master:~/cks/apiserver# k --kubeconfig config get ns
NAME              STATUS   AGE
default           Active   19h
kube-node-lease   Active   19h
kube-public       Active   19h
kube-system       Active   19h
root@master:~/cks/apiserver# vim config
.....
   server: https://192.168.211.40:30300  #6443改为30300
.... 
root@master:~/cks/apiserver# k --kubeconfig config get ns
NAME              STATUS   AGE
default           Active   19h
kube-node-lease   Active   19h
kube-public       Active   19h
kube-system       Active   19h

6. NodeRestriction AdmissionController

7. Verify NodeRestriction

root@master:~/cks/apiserver# vim /etc/kubernetes/manifests/kube-apiserver.yaml 
....
- --enable-admission-plugins=NodeRestriction
...

root@master:~/cks/apiserver# k get ns
Error from server (Forbidden): namespaces is forbidden: User "system:node:master" cannot list resource "namespaces" in API group "" at the cluster scope

root@master:~/cks/apiserver# export KUBECONFIG=/etc/kubernetes/kubelet.conf.

root@master:~/cks/apiserver# k label node master cks/test=yes
node/master labeled
root@master:~/cks/apiserver# k label node node1 cks/test=yes
Error from server (Forbidden): nodes "node1" is forbidden: node "master" is not allowed to modify node "node1"
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