使用TOKEN授权访问api-server在k8s运维场景中比较常见，

apiserver有三种级别的客户端认证方式

1，HTTPS证书认证：基于CA根证书签名的双向数字证书认证方式

2，HTTP Token认证：通过一个Token来识别合法用户

3，HTTP Base认证：通过用户名+密码的认证方式

通常的运维场景使用第二种Token较为方便Token的权限是关联service account,

# kubectl describe secrets admin-token-2q28f -n kube-system

Name: admin-token-2q28f

Namespace: kube-system

Labels:

Annotations: kubernetes.io/service-account.name: admin

kubernetes.io/service-account.uid: 93316ffa-7545-11e9-b617-00163e06992d

Type: kubernetes.io/service-account-token

Data

====

ca.crt: 1419 bytes

namespace: 11 bytes

token: eyJhbGciOiJ******

Service Account 的权限来自Clusterrolebinding-->ClusterRole

# kubectl describe serviceaccount admin -n kube-system

Name: admin

Namespace: kube-system

Labels:

Annotations: kubectl.kubernetes.io/last-applied-configuration:

{"apiVersion":"v1","kind":"ServiceAccount","metadata":{"annotations":{},"name":"admin","namespace":"kube-system"}}

Image pull secrets:

Mountable secrets: admin-token-2q28f

Tokens: admin-token-2q28f

Events:

通过clusterrolebinding 可以拿到ClusterRole对应的rolename

# kubectl get clusterrolebinding admin -o yaml

apiVersion: rbac.authorization.k8s.io/v1

kind: ClusterRoleBinding

metadata:

annotations:

kubectl.kubernetes.io/last-applied-configuration: |

{"apiVersion":"rbac.authorization.k8s.io/v1beta1","kind":"ClusterRoleBinding","metadata":{"annotations":{},"name":"admin"},"roleRef":{"apiGroup":"rbac.authorization.k8s.io","kind":"ClusterRole","name":"cluster-admin"},"subjects":[{"kind":"ServiceAccount","name":"admin","namespace":"kube-system"}]}

creationTimestamp: 2019-05-13T06:08:49Z

name: admin

resourceVersion: "1523"

selfLink: /apis/rbac.authorization.k8s.io/v1/clusterrolebindings/admin

uid: 93356439-7545-11e9-b617-00163e06992d

roleRef:

apiGroup: rbac.authorization.k8s.io

kind: ClusterRole

name: cluster-admin

subjects:

- kind: ServiceAccount

name: admin

namespace: kube-system

这个role是什么权限?

# kubectl get clusterrole cluster-admin -o yaml

apiVersion: rbac.authorization.k8s.io/v1

kind: ClusterRole

metadata:

annotations:

rbac.authorization.kubernetes.io/autoupdate: "true"

creationTimestamp: 2019-05-13T06:01:10Z

labels:

kubernetes.io/bootstrapping: rbac-defaults

name: cluster-admin

resourceVersion: "55"

selfLink: /apis/rbac.authorization.k8s.io/v1/clusterroles/cluster-admin

uid: 817e2b9e-7544-11e9-9766-00163e0e34c8

rules:

- apiGroups:

- '*'

resources:

- '*'

verbs:

- '*'

- nonResourceURLs:

- '*'

verbs:

- '*'

从clusterrole权限来看，admin关联的权限还是比较大的，正常的集群运维中建议根据自身的真实需要，去定制权限

了解完这些，分享一个小技巧，这样后面客户再有curl访问apiserver的需求，我相信你没问题了！

# kubectl describe secrets $(kubectl get secrets -n kube-system |grep admin |cut -f1 -d ' ') -n kube-system |grep -E '^token' |cut -f2 -d':'|tr -d '\t'|tr -d ' '

eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi0ycTI4ZiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjkzMzE2ZmZhLTc1NDUtMTFlOS1iNjE3LTAwMTYzZTA2OTkyZCIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDprdWJlLXN5c3RlbTphZG1pbiJ9.EQzj2LsWn2k31m-ksn9GmB1bZTi1Xjw1fnmWFgRKlwhS2QAaVnDXfV_TgUovpq5oWKh7h0gTVaNaK4KKK76yAv6GfMehpOdIO5xHCfQAWVRhla1cwUDC64tz7vJ1zGcx_lz4hKfhdXN1T8FYS0B0hf3h2OloAMfCZTzDjRWz24GVwH-WRTEwY_5tav65GiZzBTsnz1vV7NOcx-Kl8AK2HbowtBYqK05x7oOmp84FiQMwpYU-7g0c03h61zev4lvf0e-HFtqKiByPi8gD-uiVRvE-xayOz5oIESWw2GfhzfNf_uyR7eLplCKUBecVMtwVsBauNaeqU-IIJW5VIHAOxw

# TOKEN=$(kubectl describe secrets $(kubectl get secrets -n kube-system |grep admin |cut -f1 -d ' ') -n kube-system |grep -E '^token' |cut -f2 -d':'|tr -d '\t'|tr -d ' ')

# kubectl config view |grep server|cut -f 2- -d ":" | tr -d " "

https://192.168.0.130:6443

# APISERVER=$(kubectl config view |grep server|cut -f 2- -d ":" | tr -d " ")

使用curl访问apiserver

# curl -H "Authorization: Bearer $TOKEN" $APISERVER/api --insecure

{

"kind": "APIVersions",

"versions": [

"v1"

],

"serverAddressByClientCIDRs": [

{

"clientCIDR": "0.0.0.0/0",

"serverAddress": "192.168.0.130:6443"

}

]

}

作者：牧原

本文为云栖社区原创内容，未经允许不得转载。