k8s、ServiceAccount权限详解、RBAC 详解(基于角色的访问控制)，常用操作指令
文章目录
-
- Service Account应用示例
- RBAC 详解(基于角色的访问控制)
- 创建一个角色（role）---权限
- 实验二
- 常用操作指令
Service Account应用示例
概念图权限关系
我自己的理解就是，Service Account就是pod的权限
1、创建serviceaccount
[root@kub-k8s-master ~]# kubectl create serviceaccount mysa
serviceaccount/mysa created
2、查看mysa
[root@kub-k8s-master ~]# kubectl describe sa mysa
Name: mysa
Namespace: default
Labels: <none>
Annotations: <none>
Image pull secrets: <none>
Mountable secrets: mysa-token-cknwf
Tokens: mysa-token-cknwf
Events: <none>
3、查看mysa自动创建的secret
[root@kub-k8s-master ~]# kubectl get secret
NAME TYPE DATA AGE
db-user-pass Opaque 2 11h
default-token-6svwp kubernetes.io/service-account-token 3 4d23h
mysa-token-cknwf kubernetes.io/service-account-token 3 76s
mysecret Opaque 2 11h
mysecret-01 Opaque 2 6h58m
pass Opaque 1 7h6m
user Opaque 1 7h7m
4、使用mysa的sa资源配置pod
[root@kub-k8s-master prome]# vim mysa-pod.yaml
---
apiVersion: v1
kind: Pod
metadata:
name: nginx-pod
labels:
app: my-pod
spec:
containers:
- name: my-pod
image: daocloud.io/library/nginx
ports:
- name: http
containerPort: 80
serviceAccountName: mysa #指定serviceaccount的名称
5、导入
[root@kub-k8s-master prome]# kubectl apply -f mysa-pod.yaml
pod/nginx-pod created
6、查看
[root@kub-k8s-master prome]# kubectl describe pod nginx-pod
7、查看使用的token和secret（使用的是mysa的token）
[root@kub-k8s-master prome]# kubectl get pod nginx-pod -o jsonpath={".spec.volumes"}
[map[name:mysa-token-cknwf secret:map[defaultMode:420 secretName:mysa-token-cknwf]]]
[root@kub-k8s-master prome]#
RBAC 详解(基于角色的访问控制)
一个实验搞定RBAC
Role与ClusterRole
Role:角色可以由命名空间内的Role对象定义,一个Role对象只能用于授予对某一单一命名空间中资源的访问权限。
ClusterRole:整个Kubernetes集群范围内有效的角色则通过ClusterRole对象实现。
创建k8s账号与RBAC授权使用
创建账号/用户
1、创建私钥
[root@kub-k8s-master ~]# (umask 077; openssl genrsa -out soso.key 2048)
Generating RSA private key, 2048 bit long modulus
...............................+++
..........................+++
e is 65537 (0x10001)
用此私钥创建一个csr(证书签名请求)文件
[root@kub-k8s-master ~]# openssl req -new -key soso.key -out soso.csr -subj "/CN=soso"
拿着私钥和请求文件生成证书
[root@kub-k8s-master ~]# openssl x509 -req -in soso.csr -CA /etc/kubernetes/pki/ca.crt -CAkey /etc/kubernetes/pki/ca.key -CAcreateserial -out soso.crt -days 365
Signature ok
subject=/CN=soso
Getting CA Private Key
2、查看证书内容
[root@kub-k8s-master ~]# openssl x509 -in soso.crt -text -noout
生成账号
[root@kub-k8s-master ~]# kubectl config set-credentials soso --client-certificate=soso.crt --client-key=soso.key --embed-certs=true
User "soso" set.
3、设置上下文环境–指的是这个账号只能在这个环境中才能用
[root@kub-k8s-master ~]# kubectl config set-context soso@kubernetes --cluster=kubernetes --user=soso
Context "soso@kubernetes" created.
查看当前的工作上下文
[root@kub-k8s-master ~]# kubectl config view
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: DATA+OMITTED
server: https://192.168.246.166:6443
....
4、切换用户（切换上下文）
[root@kub-k8s-master ~]# kubectl config use-context soso@kubernetes
Switched to context "soso@kubernetes".
验证是否已经切换到了新的上下文
[root@kub-k8s-master ~]# kubectl config current-context
soso@kubernetes
5.测试（还未赋予权限）
[root@kub-k8s-master ~]# kubectl get pod
Error from server (Forbidden): pods is forbidden: User "soso" cannot list resource "pods" in API group "" in the namespace "default"
创建一个角色（role）—权限
1.切回管理帐号先
[root@kub-k8s-master ~]# kubectl config use-context kubernetes-admin@kubernetes
Switched to context "kubernetes-admin@kubernetes".
创建角色：
[root@kub-k8s-master ~]# kubectl create role myrole --verb=get,list,watch --resource=pod,svc
role.rbac.authorization.k8s.io/myrole created
--verb： 相当于是权限
--resource：给什么资源使用
2.绑定用户soso（上面创建的用户），绑定role为myrole
[root@kub-k8s-master ~]# kubectl create rolebinding myrole-binding --role=myrole --user=soso
rolebinding.rbac.authorization.k8s.io/myrole-binding created
3.切换用户
[root@kub-k8s-master ~]# kubectl config use-context soso@kubernetes
Switched to context "soso@kubernetes".
4.查看权限（只授权了default名称空间pod和svc的get，list，watch权限）
[root@kub-k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
lifecycle-demo 1/1 Running 1 22h
mypod 1/1 Running 0 8h
nginx-configmap 1/1 Running 0 4h29m
nginx-pod 1/1 Running 0 39m
测试
[root@kub-k8s-master ~]# kubectl get pod -n kube-system #无权访问kube-system
Error from server (Forbidden): pods is forbidden: User "soso" cannot list resource "pods" in API group "" in the namespace "kube-system"
[root@kub-k8s-master ~]# kubectl delete pod nginx-pod #无权限删除
Error from server (Forbidden): pods "nginx-pod" is forbidden: User "soso" cannot delete resource "pods" in API group "" in the namespace "default"
5.切换用户
[root@kub-k8s-master ~]# kubectl config use-context kubernetes-admin@kubernetes
Switched to context "kubernetes-admin@kubernetes".
实验二
6.删除soso账号之前绑定的rolebinding
[root@kub-k8s-master ~]# kubectl delete rolebinding myrole-binding
rolebinding.rbac.authorization.k8s.io "myrole-binding" deleted
7.创建clusterrole #可以访问全部的namespace
[root@kub-k8s-master ~]# kubectl create clusterrole myclusterrole --verb=get,list,watch --resource=pod,svc
clusterrole.rbac.authorization.k8s.io/myclusterrole created
8.绑定集群角色到用户soso
[root@kub-k8s-master ~]# kubectl create clusterrolebinding my-cluster-rolebinding --clusterrole=myclusterrole --user=soso
clusterrolebinding.rbac.authorization.k8s.io/my-cluster-rolebinding created
8.切换账号
[root@kub-k8s-master ~]# kubectl config use-context soso@kubernetes
Switched to context "soso@kubernetes".
9.查看权限 查看kube-system空间的pod
[root@kub-k8s-master ~]# kubectl get pod -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-5644d7b6d9-sm8hs 1/1 Running 0 5d
coredns-5644d7b6d9-vddll 1/1 Running 0 5d
etcd-kub-k8s-master 1/1 Running 0 5d
...
注意：10.切换为管理员用户
[root@kub-k8s-master ~]# kubectl config use-context kubernetes-admin@kubernetes
常用操作指令
设置工作上下文（前提得有用户）
[root@kub-k8s-master ~]# kubectl config set-context soso@kubernetes --cluster=kubernetes --user=soso
Context "soso@kubernetes" created.
查看当前的工作上下文
[root@kub-k8s-master ~]# kubectl config view
apiVersion: v1
clusters:
- cluster:
....
切换上下文（切换用户）
[root@kub-k8s-master ~]# kubectl config use-context soso@kubernetes
Switched to context "soso@kubernetes".
切换为管理员用户
[root@kub-k8s-master prome]# kubectl config use-context kubernetes-admin@kubernetes
Switched to context "kubernetes-admin@kubernetes".