k8s—安全机制_代码007(未授权)

本文介绍: 请求api资源：1、认证2、鉴权3、准入机制三个条件都通过，才可以在k8s集群当中创建。

k8s的安全机制，分布式集群管理工具，就是容器编排。安全机制的核心：APIserver。为整个集群内部通信的中介，也是外控控制的入口。所有的机制都是围绕apiserver来进行设计：

请求api资源：

1、认证

2、鉴权

3、准入机制

三个条件都通过，才可以在k8s集群当中创建。

useradd lucky
passwd lucky
#创建一个用户
 
mkdir lucky
cd /usr/local/bin/
chmod +x cfssl*
 
vim user-cert.sh
cat > lucky-csr.json <<EOF
{
 "CN": "lucky",
 "hosts": [],
 "key": {
   "algo": "rsa",
   "size": 2048
},
 "names": [
  {
   "C": "CN",
   "ST": "Nanjing",
   "O": "k8s",
   "OU": "system"
   }
  ]
}
  EOF
 
chmod +x user-cert.sh
./user-cert.sh
 
cd /etc/kubernetes/pki/
cfssl gencert -ca=ca.crt -ca-key=ca.key -profile=kubernetes /opt/lucky/lucky-csr.json | cfssljson -bare lucky
#基于设定的信息，创建一个认证证书

cd /opt/lucky
 
vim rbac-kubeconfig.sh
APISERVER=$1
# 设置集群参数
export KUBE_APISERVER="https://$APISERVER:6443"
kubectl config set-cluster kubernetes 
  --certificate-authority=/etc/kubernetes/pki/ca.crt 
  --embed-certs=true 
  --server=${KUBE_APISERVER} 
  --kubeconfig=lucky.kubeconfig
 
# 设置客户端认证参数
kubectl config set-credentials lucky 
  --client-key=/etc/kubernetes/pki/lucky-key.pem 
  --client-certificate=/etc/kubernetes/pki/lucky.pem 
  --embed-certs=true 
  --kubeconfig=lucky.kubeconfig
 
# 设置上下文参数
kubectl config set-context kubernetes 
  --cluster=kubernetes 
  --user=lucky 
  --namespace=lucky-cloud 
  --kubeconfig=lucky.kubeconfig
  
kubectl create namespace lucky-cloud
chmod +x rbac-kubeconfig.sh
./rbac-kubeconfig.sh 192.168.10.10
#此处为master的ip
 
# 使用上下文参数生成 lucky.kubeconfig 文件
kubectl config use-context kubernetes --kubeconfig=lucky.kubeconfig
 
//查看证书
cat lucky.kubeconfig

mkdir /home/lucky/.kube
cp lucky.kubeconfig /home/lucky/.kube/config
chown -R lucky:lucky /home/lucky/.kube/
 
 
//RBAC授权
vim rbac.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: lucky-cloud
  name: pod-reader
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "watch", "list", "create"]
 
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: read-pods
  namespace: lucky-cloud
subjects:
- kind: User
  name: lucky
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: pod-reader
  apiGroup: rbac.authorization.k8s.io
  
  
kubectl apply -f rbac.yaml
 
kubectl get role,rolebinding -n lucky-cloud

//切换用户，测试操作权限
su - lucky
 
vim pod-test.yaml
apiVersion: v1
kind: Pod
metadata:
  name: pod-test
spec:
  containers:
    - name: nginx
      image: nginx
 
 
kubectl create -f pod-test.yaml
 
kubectl get pods -o wide

//访问 svc 资源就会被拒绝
kubectl get svc
 
//也无法访问 default 命名空间
kubectl get pods -n default
 
//使用 root 用户查看
kubectl get pods -n lucky-cloud -o wide
 
//也可以通过绑定 admin 角色，来获得管理员权限
kubectl create rolebinding lucky-admin-binding --clusterrole=admin --user=lucky --namespace=lucky