浅析k8s中各组件和kube apiserver通信时的认证和鉴权问题

目录

• 背景
• kubectl的身份和权限
• kubectl用的是什么身份？
• 能操作哪些资源呢？
• kube-scheduler的身份和权限
• kube-scheduler用的是什么身份？
• kubelet的身份和权限
• kubelet用的是什么身份？
• kubelet能操作哪些资源？
• 验证kubelet的权限
• calico
• calico用的是什么身份？
• pod
• pod用的是什么身份？
• 总结

背景

和master节点kube api-server通信的组件有很多，包括：

• kubelet
• calico
• scheduler
• kubectl
• 某些pod可能会和kube api-server通信

这些组件和api-server通信时用的是什么身份，可以操作哪些api资源呢？

本文使用的k8s集群是用kubekey搭建，命令是./kk create cluster --with-kubernetes v1.21.5 --with-kubesphere v3.2.1

kubectl的身份和权限

kubectl用的是什么身份？

kubectl默认会用到.kube/config配置，其中包含证书信息

root@ip-172-31-14-204:~# cat .kube/config
apiVersion: v1
...
users:
- name: kubernetes-admin
  user:
    client-certificate-data: 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
...

可以看到这个证书的CN是kubernetes-admin，O是system:masters。根据文档可以知道，这表示证书代表的用户是kubernetes-admin，用户组是system:masters。

root@ip-172-31-14-204:~# echo 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 | base64 -d | openssl x509  -noout -text
Certificate:
    ...
        Subject: O = system:masters, CN = kubernetes-admin

那这个证书代表的用户能操作哪些资源呢？

能操作哪些资源呢？

这个需要看"用户kubernetes-admin"、"用户组system:masters"在集群中绑定了什么"角色"。

可以看到它绑定了"ClusterRole/cluster-admin"，这个角色可以对所有资源做任意操作。

root@ip-172-31-14-204:~# kubectl get ClusterRoleBinding -A -o wide | grep system:masters
cluster-admin                                          ClusterRole/cluster-admin                                                          33h                                    system:masters

可以通过kubectl get ClusterRole/cluster-admin -o yaml查看角色的权限。

所以，.kube/config证书中代表的用户身份可以对所有资源做任意操作。

kube-scheduler的身份和权限

kube-scheduler用的是什么身份？

在master节点上查看scheduler进程，可以"大胆猜测"用的是/etc/kubernetes/scheduler.conf中的证书信息。

在我的k8s环境中，kube-scheduler是运行在pod中的，不过pod和宿主机的/etc/kubernetes/scheduler.conf文件是一样的

root@ip-172-31-14-33:~# ps aux|grep kube-scheduler
root     51897  0.2  0.7 753012 57736 ?        Ssl  May25   3:59 kube-scheduler --authentication-kubeconfig=/etc/kubernetes/scheduler.conf --authorization-kubeconfig=/etc/kubernetes/scheduler.conf --bind-address=0.0.0.0 --feature-gates=RotateKubeletServerCertificate=true,TTLAfterFinished=true,ExpandCSIVolumes=true,CSIStorageCapacity=true --kubeconfig=/etc/kubernetes/scheduler.conf --leader-elect=true --port=0

查看证书的Subject信息，可以看到用户是system:kube-scheduler

root@ip-172-31-14-33:~# echo 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 | base64 -d |openssl x509  -noout -text
Certificate:
    ...
        Subject: CN = system:kube-scheduler

可以看到"用户system:kube-scheduler"绑定了两个角色。

root@ip-172-31-14-33:~# kubectl get ClusterRoleBindings -o wide |grep system:kube-scheduler
system:kube-scheduler                                  ClusterRole/system:kube-scheduler                                                  31h   system:kube-scheduler
system:volume-scheduler                                ClusterRole/system:volume-scheduler                                                31h   system:kube-scheduler

kubelet的身份和权限

kubelet用的是什么身份？

root@ip-172-31-14-204:~# ps aux|grep kubelet
root     54396  7.7  2.8 1966128 113860 ?      Ssl  08:14  29:54 /usr/local/bin/kubelet ... --kubeconfig=/etc/kubernetes/kubelet.conf ...

在worker节点上可以看到kubelet进程参数，api-server信息在/etc/kubernetes/kubelet.conf文件中

可以看到是通过证书认证的

root@ip-172-31-14-204:/etc/kubernetes/manifests# cat /etc/kubernetes/kubelet.conf
apiVersion: v1
...
users:
- name: system:node:ip-172-31-14-33
  user:
    client-certificate: /var/lib/kubelet/pki/kubelet-client-current.pem
    client-key: /var/lib/kubelet/pki/kubelet-client-current.pem

查看证书的Subject信息，可以知道证书代表的"用户"是"system:node:ip-172-31-14-204"，"用户组"是"system:nodes"

root@ip-172-31-14-204:~# openssl x509 -in /var/lib/kubelet/pki/kubelet-client-current.pem -noout -text
Certificate:
    ...
        Subject: O = system:nodes, CN = system:node:ip-172-31-14-204

那这个kubelet的证书代表的用户能操作哪些资源呢？它可以用来像"集群管理员"那样创建pod吗？

kubelet能操作哪些资源？

按照之前流程，我们来看一下"用户system:node:ip-172-31-14-204"、"用户组system:nodes"在集群中绑定了什么"角色"。

root@ip-172-31-14-204:~# kubectl get ClusterRoleBinding -A|grep system:nodes
root@ip-172-31-14-204:~# kubectl get ClusterRoleBinding -A|grep "system:node:ip-172-31-14-204"
root@ip-172-31-14-204:~#

会发现"用户和用户组"没有绑定任何一个角色，这和kubectl、kube-scheduler就很不一样了。

在 使用Node鉴权文档中提到，kube apiserver对kubelet的鉴权比较特殊。

当发现请求的用户在system:nodes组中，用户名是system:node:时，就限制这个请求只能做有限的操作，比如

• 读操作
  • services
  • pod
  • 绑定到当前node的pod的secret、configMap
• 写操作（如果开启了NodeRestriction准入插件，就只能修改kubelet所在node的资源）
  • 创建节点、修改节点状态
  • 创建pod、pod状态

似乎如果没有开启NodeRestriction准入插件，就能让kubelet在任意node上创建pod。

红蓝对抗中，如果能让kubelet在任意node上创建pod，就能用来横移

文档中写到，这里的能力可能随着k8s版本变化而变化，以确保kubelet最小权限，默认安全。所以，kubelet到底能操作哪些资源，感觉还是来测试一下比较好，下面就来验证一下kubelet的权限。

验证kubelet的权限

我们先用kubelet配置文件覆盖kubectl的默认配置，然后就可以用kubectl命令来验证。

root@ip-172-31-14-204:~# mv .kube/config .kube/config.bak
root@ip-172-31-14-204:~# ps aux|grep kubele
root     59075  7.9  2.7 1956332 108712 ?      Ssl  03:37   2:51 /usr/local/bin/kubelet ... --kubeconfig=/etc/kubernetes/kubelet.conf ...
root@ip-172-31-14-204:~# cp /etc/kubernetes/kubelet.conf .kube/config

可以看到不能够创建pod

root@ip-172-31-14-204:~# kubectl run httpbin --image kennethreitz/httpbin
Error from server (Forbidden): pods "httpbin" is forbidden: pod does not have "kubernetes.io/config.mirror" annotation, node "ip-172-31-14-204" can only create mirror pod

查看pod信息是可以的

root@ip-172-31-14-204:~# kubectl get pods -A
NAMESPACE                      NAME                                               READY   STATUS      RESTARTS   AGE
default                        tail                                               1/1     Running     0          25h
kube-system                    calico-kube-controllers-846b5f484d-vzlhw           1/1     Running     0          27h
...
root@ip-172-31-14-204:~# kubectl describe pod devops-27558900-m69pc -n kubesphere-devops-system
Name:         devops-27558900-m69pc
...

查看secret和configMap是不允许的

root@ip-172-31-14-204:~# kubectl get secrets -A
Error from server (Forbidden): secrets is forbidden: User "system:node:ip-172-31-14-204" cannot list resource "secrets" in API group "" at the cluster scope: can only read namespaced object of this type
root@ip-172-31-14-204:~# kubectl get configmap
Error from server (Forbidden): configmaps is forbidden: User "system:node:ip-172-31-14-204" cannot list resource "configmaps" in API group "" in the namespace "default": No Object name found
root@ip-172-31-14-204:~#

小结：kubelet证书可以用来查看pod信息，不能创建pod、不能查看所有命名空间的secret和configMap。看起来和文档中的说明一致。

calico

calico用的是什么身份？

root@ip-172-31-14-204:~# cat /etc/cni/net.d/calico-kubeconfig
# Kubeconfig file for Calico CNI plugin. Installed by calico/node.
...
users:
- name: calico
  user:
    token: eyJhbGciOiJSUzI1NiIsImtpZCI6ImV6bEstc2QtRTNTaE1ySFg2SWdxMjY2aHpkVFBEWU56SGdfaVdZRXZ4YncifQ.eyJhdWQiOlsiaHR0cHM6Ly9rdWJlcm5ldGVzLmRlZmF1bHQuc3ZjLmNsdXN0ZXIubG9jYWwiXSwiZXhwIjoxNjg1MDIyOTAwLCJpYXQiOjE2NTM0ODY5MDAsImlzcyI6Imh0dHBzOi8va3ViZXJuZXRlcy5kZWZhdWx0LnN2Yy5jbHVzdGVyLmxvY2FsIiwia3ViZXJuZXRlcy5pbyI6eyJuYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsInBvZCI6eyJuYW1lIjoiY2FsaWNvLW5vZGUtcWR0ZmIiLCJ1aWQiOiI4N2U4ZmM3ZC0yYTg5LTQ1OTgtOWQyOC1mZDYyNGIwODk2MDMifSwic2VydmljZWFjY291bnQiOnsibmFtZSI6ImNhbGljby1ub2RlIiwidWlkIjoiOTEzNzUwZWItYmRhNC00YjJmLTgxNjctNDZjOTkxNjk5YWRkIn0sIndhcm5hZnRlciI6MTY1MzQ5MDUwN30sIm5iZiI6MTY1MzQ4NjkwMCwic3ViIjoic3lzdGVtOnNlcnZpY2VhY2NvdW50Omt1YmUtc3lzdGVtOmNhbGljby1ub2RlIn0.mF1Yek_sSBa2nlQIbdJlEZtv3anjIUFPFpj8Ta8Zn1t6vxYEZjswbPxrw-90sbEVGR30GWytUjr3X1tmjWTP0fL9ltAPvcM0tRg6MoLuGdC2uZFbt-zfKFEn42Yme-NuVOKO3K2otgZNt0ym0gYRT41wLCqOuKLq-SHAkHdvIOZ1eVAu0OsN3ccgSFf2nsuBqbDphd4ShqRPNXl1m66UEDlb4WiPmuSPuzRmMiV706YbBPxMUzn9Ve4o4IfBbeBufp_edSWPPW763EGqZmI7qZg-78SUbtAJ6m8Qkq6TrDIcaJbI3Mrl4EsrnE3v3MGMOogfXXs3-yU-NZl3ilQt6Q
...

可以看到用的是token令牌。这个token令牌是一个jwt字符串，base64解码后的payload部分如下，可以看到"ServiceAccount"是calico-node，命名空间是kube-system

{"aud":["https://kubernetes.default.svc.cluster.local"],"exp":1685022900,"iat":1653486900,"iss":"https://kubernetes.default.svc.cluster.local","kubernetes.io":{"namespace":"kube-system","pod":{"name":"calico-node-qdtfb","uid":"87e8fc7d-2a89-4598-9d28-fd624b089603"},"serviceaccount":{"name":"calico-node","uid":"913750eb-bda4-4b2f-8167-46c991699add"},"warnafter":1653490507},"nbf":1653486900,"sub":"system:serviceaccount:kube-system:calico-nodeIn0

可以看到，这个"ServiceAccount"被绑定到了"ClusterRole/calico-node"角色。

root@ip-172-31-14-204:/home/ubuntu# kubectl get clusterrolebinding -o wide|grep kube-system/calico-node
calico-node                                            ClusterRole/calico-node                                                            34h                                                                                      kube-system/calico-node

pod

pod用的是什么身份？

大部分pod会挂载一个token在/var/run/secrets/kubernetes.io/serviceaccount/token位置，这个token也是一个jwt字符串。

root@ip-172-31-14-204:/home/ubuntu# kubectl exec -ti tail -- sh
/ # cat /var/run/secrets/kubernetes.io/serviceaccount/token
eyJhbGciOiJSUzI1NiIsImtpZCI6ImV6bEstc2QtRTNTaE1ySFg2SWdxMjY2aHpkVFBEWU56SGdfaVdZRXZ4YncifQ.eyJhdWQiOlsiaHR0cHM6Ly9rdWJlcm5ldGVzLmRlZmF1bHQuc3ZjLmNsdXN0ZXIubG9jYWwiXSwiZXhwIjoxNjg1MDk4NTUwLCJpYXQiOjE2NTM1NjI1NTAsImlzcyI6Imh0dHBzOi8va3ViZXJuZXRlcy5kZWZhdWx0LnN2Yy5jbHVzdGVyLmxvY2FsIiwia3ViZXJuZXRlcy5pbyI6eyJuYW1lc3BhY2UiOiJkZWZhdWx0IiwicG9kIjp7Im5hbWUiOiJ0YWlsIiwidWlkIjoiYmQzZGRlZjAtODViYy00MmI4LThjZWYtMjQwZTkwMjViYWQ5In0sInNlcnZpY2VhY2NvdW50Ijp7Im5hbWUiOiJkZWZhdWx0IiwidWlkIjoiZGI5YjQ5MGMtYzU5MS00NDc0LTljOTAtY2U3ZjZmMmRjYjYzIn0sIndhcm5hZnRlciI6MTY1MzU2NjE1N30sIm5iZiI6MTY1MzU2MjU1MCwic3ViIjoic3lzdGVtOnNlcnZpY2VhY2NvdW50OmRlZmF1bHQ6ZGVmYXVsdCJ9.L388ZKZWvHYf7Yvt6tA7t8k2QMYcsI9BDcYtoxAgOJiEiwf3LKFQmdH8KF4PnI0kjM3Bg80WztFznotwZqCwCNfXMVMl4_iLGHDAgVB3tsdv9ljZ9FUJbn52PD5aWHSWRqjpyQzv8_89dlnnbGQLHg4M8Ly4OkGuWUOnE1x6vgSa1MkjhrnrJEPnnJo5Fy_vyRdvO2A9iyGh7cC97Ns6WWFkeD7741wSkGkoNkZKqJTyfaa_KScprPiVPYuisi4HkYrP71NzZA_i34Dk-IsomySR4h3WWw_88-kfL_lWZ8PDu5NuVekZZ4xfIQjA6oDhXT_Hx4iIlhwVwgYuTW4V-g

base64解码后，payload中也能看到一个服务账号ServiceAccount，这个ServiceAccount也有可能和一个"角色"绑定。你可以动手查看一下自己的pod。

总结

k8s中"X509 客户证书"和"服务账号令牌"应该是身份认证最常见的两种方式，都能代表"用户"或"用户组"信息。

大部分的组件(包括scheduler、calico、kubectl、pod)鉴权都是依赖RBAC模型，也就是"用户或"用户组"绑定的"角色"规定了能访问哪些资源。

kubelet的鉴权比较特殊，是依赖Node鉴权模型。

用户认证文档中还提到api访问控制的其他方法。

到此这篇关于k8s中各组件和kube apiserver通信时的认证和鉴权的文章就介绍到这了,更多相关k8s认证和鉴权内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！