概述

本文介绍如何使用github账户去关联自己kubernetes账户。达到如下效果：

1. 使用github用户email作为kubernetes用户，如fhtjob@hotmail.com
2. 创建对应的clusterrole绑定给fhtjob@hotmail.com这个用户
3. 给fhtjob@hotmail这个用户创 建一个kubeconfig文件，让改用户可以使用kubectl命令操作集群，且只有部分权限

dex介绍

dex 是一个统一认证的服务，支持各种认证协议如Ouath2 ldap等，自己可以作为一个identity provider,也可以连到别的id provider(如github)上,dex作为一个中间代理.

流程

 http://47.52.197.163:5555 http://47.52.197.163:32000
 人(浏览器） dex client dex server github kubectl kubernetes server
 | login(scope) | | | | |
 |------1-------->| | | | |
 | |----------2------------->| | | |
 | | |----------3----------->| | |
 | | | id_token | | |
 | | |<---------4------------| callback | |
 | id_token |<----------5-------------|callback | | |
 |<-------6-------| | | | |
 | | | | id_token | |
 |------------------------------------------------7-------------------------------------------->| id_token |
 | | | | |----------8------------>|
 | | | | | | valid? 
 | | | | | | expired?
 | | | | | | user Authorized?
 | | | | |<---------9-------------| X<----------------------------------------------10---------------------------------------------| |
 | | | | | |
 | | | | | |
 | | | | | |

• scope: 你需要哪些信息，如邮箱,openid,用户名等
• id_token: 加密后的你需要的信息
• dex client: dex的客户端，比如可以是我们自己写的管理的服务端，会去调用第三方登录的流程，或者我们写的一个网站后台处理登录的逻辑
• dex server: dex的服务端，一边作为client的服务端，另一边其实是github的客户端

1. 用户在浏览器发起登录请求
2. dexclient把请求重定向给dexserver
3. dexserver重定向给github，这时用户就会跳转到github的页面去授权允许访问哪些信息
4. github把对应信息加密调用dexserver的回调url(http://47.52.197.163:32000/callback)把信息传给dex server, 注意区分dex client的回调
5. dexserver把信息回调给dex client(http://47.52.197.163:5555/callback)
6. 浏览器中拿到token
7. 把token加到kubeconfig文件中，让kubectl可以使用
8. kubectl把token传给kubernetes server, server有 dex server的公钥可以解析token，拿到username, 看是否过期，看授权是否允许执行该动作
9. 把执行结果返回给kubectl

环境介绍与注意事项

• 采用云服务器进行该实验，Floatingip是47.52.197.163
• 你需要有一个github账户，我的是github.com/fanux 把email(fhtjob@hotmail.com)作为kubernetes账户
• 服务器上要装golang
• 官方教程有很多坑，建议看我的教程
• 需要有个k8s集群，那么我最推荐的安装方式当然是购买我的安装包哈哈

安装

修改kube apiserver配置

[root@master2 ~]# cat /etc/kubernetes/manifests/kube-apiserver.yaml apiVersion: v1 kind: Pod metadata: annotations: scheduler.alpha.kubernetes.io/critical-pod: "" creationTimestamp: null labels: component: kube-apiserver tier: control-plane name: kube-apiserver namespace: kube-system spec: containers: - command: - kube-apiserver - --oidc-issuer-url=https://47.52.197.163:32000 # 加上这五个参数 - --oidc-client-id=example-app - --oidc-ca-file=/etc/kubernetes/ssl/ca.pem # dex证书，挂载进来的 - --oidc-username-claim=email - --oidc-groups-claim=groups ... - mountPath: /etc/kubernetes/ssl # 把dex的证书挂进去给apiserver使用 name: dex readOnly: true volumes: - hostPath: path: /etc/kubernetes/ssl type: DirectoryOrCreate name: dex

用kubeadm安装的修改/etc/kubernetes/manifests/kube-apiserver.yaml这个文件即可，建议不要直接修改，拷贝出来修改再复制回去，防止kubelet去拉swap文件导致controller manager异常

创建github app

点你github头像，settings->developer settins -> new oauth app

Application name: example-app
Homepage URL：https://47.52.197.163:32000
Authorization callback URL: https://47.52.197.163:32000/callback

URL千万别填错，注意是dex server的URL而不是dex client的5555

然后你就能看到一个ID一个secrect 后面需要用

部署dex

没装go的自己去装。。。

go get github.com/coreos/dex 
cd $GOPATH/src/github.com/coreos/dex

生成证书
gencert.sh需要改一下，把我们IP加进去

[alt_names]
DNS.1 = dex.example.com
IP.1 = 47.52.197.163
IP.2 = 172.31.244.238

$ cd examples/k8s $ ./gencert.sh $ cp examples/k8s/ssl /etc/kubernetes # 可曾记得我们挂载的目录

创建secrect,这个会给dex server用

$ kubectl create secret tls dex.example.com.tls --cert=ssl/cert.pem --key=ssl/key.pem

再创建一个secrect给dex server Github OAuth2 客户端用，dex server是github的一个客户端要理解

$ kubectl create secret \
 generic github-client \
 --from-literal=client-id=$GITHUB_CLIENT_ID \ # 这俩东西替换成在github页面上创建的APP clientid和secrect --from-literal=client-secret=$GITHUB_CLIENT_SECRET

启动dex.yaml，注意代码里直接clone下来的没有配置存储，而且镜像比较老，建议用我的：

apiVersion: extensions/v1beta1 kind: Deployment metadata: labels: app: dex name: dex spec: replicas: 1 template: metadata: labels: app: dex spec: containers: - image: quay.io/coreos/dex:v2.10.0 name: dex command: ["/usr/local/bin/dex", "serve", "/etc/dex/cfg/config.yaml"] ports: - name: https containerPort: 5556 volumeMounts: - name: config mountPath: /etc/dex/cfg - name: data mountPath: /etc/example - name: tls mountPath: /etc/dex/tls env: - name: GITHUB_CLIENT_ID valueFrom: secretKeyRef: name: github-client key: client-id - name: GITHUB_CLIENT_SECRET valueFrom: secretKeyRef: name: github-client key: client-secret volumes: - name: data hostPath: path: /data/example - name: config configMap: name: dex items: - key: config.yaml path: config.yaml - name: tls secret: secretName: dex.example.com.tls --- kind: ConfigMap apiVersion: v1 metadata: name: dex data: config.yaml: | issuer: https://47.52.197.163:32000 storage: type: sqlite3 config: file: /etc/example/dex.db web: https: 0.0.0.0:5556 tlsCert: /etc/dex/tls/tls.crt tlsKey: /etc/dex/tls/tls.key connectors: - type: github id: github name: GitHub config: clientID: $GITHUB_CLIENT_ID clientSecret: $GITHUB_CLIENT_SECRET redirectURI: https://47.52.197.163:32000/callback org: kubernetes oauth2: skipApprovalScreen: true staticClients: - id: example-app redirectURIs: - 'http://47.52.197.163:5555/callback' name: 'Example App' secret: ZXhhbXBsZS1hcHAtc2VjcmV0 enablePasswordDB: true staticPasswords: - email: "admin@example.com"  # bcrypt hash of the string "password" hash: "$2a$10$2b2cU8CPhOTaGrs1HRQuAueS7JTT5ZHsHSzYiFPm1leZck7Mc8T4W" username: "admin" userID: "08a8684b-db88-4b73-90a9-3cd1661f5466" --- apiVersion: v1 kind: Service metadata: name: dex spec: type: NodePort ports: - name: dex port: 5556 protocol: TCP targetPort: 5556 nodePort: 32000 selector: app: dex

主要修改了：

• 镜像
• 一些地址，改成自己的IP
• 存储，我改成了sqlite, 需要挂载一个文件进去，在宿主机上创建一个文件

$ touch /data/example/dex.db $ kubectl create -f dex.yaml

启动dex client

编译客户端dex目录下：

make

启动客户端：

$ ./bin/example-app --issuer https://47.52.197.163:32000 --issuer-root-ca examples/k8s/ssl/ca.pem --redirect-uri http://47.52.197.163:5555/callback

浏览器访问获取token

浏览器访问 http://47.52.197.163:5555 ,点击login后能看到 Log in to dex 下面可以选 log in with Email 和 log in with github
点击log in with github 授权后得到：

Token:

eyJhbGciOiJSUzI1NiIsImtpZCI6ImMyZWIzYzkwMmM0NDliMTYwMGNjNzNhMWYyNWVjMjI0MDY4NmE0OGMifQ.eyJpc3MiOiJodHRwczovLzQ3LjUyLjE5Ny4xNjM6MzIwMDAiLCJzdWIiOiJDZ2M0T1RFeU5UVTNFZ1puYVhSb2RXSSIsImF1ZCI6ImV4YW1wbGUtYXBwIiwiZXhwIjoxNTI0MDIwNzA3LCJpYXQiOjE1MjM5MzQzMDcsImF0X2hhc2giOiI5czJob0lzUHRlMW9nc3VKemRab1pnIiwiZW1haWwiOiJmaHRqb2JAaG90bWFpbC5jb20iLCJlbWFpbF92ZXJpZmllZCI6dHJ1ZSwibmFtZSI6InN0ZXZlbiJ9.uJAL08BZioSWPaEFh8R50JQVRw6QXgC1n3sn5ovzaoauy51YFjdSh08UZT8KQon8R5JdZ4U06BczwmOG_tT0mWVd_mDqLnRm6lGpm9znYiC1OLNGZOdzuQVsuxe4Lk1YOvxTsJQtpYuOcXXKkwmdfWNeh4VyZoALiVZxLfL44lSnU55JutLNnGD5S6Aiu6YF0xwlcX5Eq1j2pYtg4isnPtU4k6gbiEYCMPm0Gs3FPljnLT7a-TB1tjZLc4RDwBZ4OoiYRu5mAmH5SHHq1_TS9wDTXX16KlQTG9tS_I11n--1grYTz5WondBoM14BJebDdcSF7nRWJ-I8CU_UYu6gcA
Claims:

{
 "iss": "https://47.52.197.163:32000",
 "sub": "Cgc4OTEyNTU3EgZnaXRodWI",
 "aud": "example-app",
 "exp": 1524020707,
 "iat": 1523934307,
 "at_hash": "9s2hoIsPte1ogsuJzdZoZg",
 "email": "fhtjob@hotmail.com",
 "email_verified": true,
 "name": "steven"
}
Refresh Token:

Chlrem12bDdmdGJ1dWNlYnk0b2llcWd0YzNqEhloNGhwbmlsZnByZ29mdWdsdWZ6bGp4cHhs

那么 恭喜你成功了, 这个token就是我们要的东西

验证tocken

curl -H "Authorization: Bearer eyJhbGciOiJSUzI1NiIsImtpZCI6ImJjOTU0NjdlM2I0OTE5YWE1OTEzZDNkMDU3NGM2ZTRjYjBjY2NhNzgifQ.eyJpc3MiOiJodHRwczovLzQ3LjUyLjE5Ny4xNjM6MzIwMDAiLCJzdWIiOiJDZ2M0T1RFeU5UVTNFZ1puYVhSb2RXSSIsImF1ZCI6ImV4YW1wbGUtYXBwIiwiZXhwIjoxNTIzOTYyNjUyLCJpYXQiOjE1MjM4NzYyNTIsImF0X2hhc2giOiJFUXRWWm5ObE50c2hhWERfZ3N2UkNBIiwiZW1haWwiOiJmaHRqb2JAaG90bWFpbC5jb20iLCJlbWFpbF92ZXJpZmllZCI6dHJ1ZSwibmFtZSI6InN0ZXZlbiJ9.vu0keGMoRGg6OAYpMZNN9zm4pnKXGyXDkZaRNj6MXDY9XsfnBDT4HnXkY17Lvm1ow0xPbq9cgVL3JBZT73jiddgFNAIXJffHfPejlVRSqXx9iF1uEcNIc5tDA1hUPtBrX8n_rzdz0sZsPMb4ZYMx3AdEylszpVrS_OelbB4I_2eLfO0KzwcEknOgV8cZZghCCITl6ZTOeeWEv5FPvJjRC2rpu_MkSY5tAf30SITwldFUMgF8ei3aPrZdojPLgqUWtxKaDmPpcHVLhYr0sLE_BnDZLjGP4ff8l5yy_EfDc7sQsrJR7StwZXRnK-n2omqaV3z-n5IxaUty85e_97FA1g" -k https://172.31.244.238:6443/api/v1/namespaces/default/pods

你会发现

{
 "kind": "Status",
 "apiVersion": "v1",
 "metadata": {

 },
 "status": "Failure",
 "message": "pods is forbidden: User \"fhtjob@hotmail.com\" cannot list pods in the namespace \"default\"",
 "reason": "Forbidden",
 "details": {
 "kind": "pods"
 },
 "code": 403
}

fhtjob@hotmail.com这个用户没有权限访问pods。我们给他创建一个角色绑定：

[root@master2 dex]# cat examples/k8s/role.yaml kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: read-secrets-global subjects: - kind: User name: "fhtjob@hotmail.com" # Name is case sensitive apiGroup: rbac.authorization.k8s.io roleRef: kind: ClusterRole name: cluster-admin # 超级用户给他 apiGroup: rbac.authorization.k8s.io

$ kubectl create -f examples/k8s/role.yaml

再次curl:

ot@master2 dex]# curl -H "Authorization: Bearer eyJhbGciOiJSUzI1NiIsImtpZCI6ImJjOTU0NjdlM2I0OTE5YWE1OTEzZDNkMDU3NGM2ZTRjYjBjY2NhNzgifQ.eyJpc3MiOiJodHRwczovLzQ3LjUyLjE5Ny4xNjM6MzIwMDAiLCJzdWIiOiJDZ2M0T1RFeU5UVTNFZ1puYVhSb2RXSSIsImF1ZCI6ImV4YW1wbGUtYXBwIiwiZXhwIjoxNTIzOTYyNjUyLCJpYXQiOjE1MjM4NzYyNTIsImF0X2hhc2giOiJFUXRWWm5ObE50c2hhWERfZ3N2UkNBIiwiZW1haWwiOiJmaHRqb2JAaG90bWFpbC5jb20iLCJlbWFpbF92ZXJpZmllZCI6dHJ1ZSwibmFtZSI6InN0ZXZlbiJ9.vu0keGMoRGg6OAYpMZNN9zm4pnKXGyXDkZaRNj6MXDY9XsfnBDT4HnXkY17Lvm1ow0xPbq9cgVL3JBZT73jiddgFNAIXJffHfPejlVRSqXx9iF1uEcNIc5tDA1hUPtBrX8n_rzdz0sZsPMb4ZYMx3AdEylszpVrS_OelbB4I_2eLfO0KzwcEknOgV8cZZghCCITl6ZTOeeWEv5FPvJjRC2rpu_MkSY5tAf30SITwldFUMgF8ei3aPrZdojPLgqUWtxKaDmPpcHVLhYr0sLE_BnDZLjGP4ff8l5yy_EfDc7sQsrJR7StwZXRnK-n2omqaV3z-n5IxaUty85e_97FA1g" -k https://172.31.244.238:6443/api/v1/namespaces/default/pods
{
 "kind": "PodList",
 "apiVersion": "v1",
 "metadata": {
 "selfLink": "/api/v1/namespaces/default/pods",
 "resourceVersion": "333066"
 },
 "items": [
 {
 "metadata": {
 "name": "dex-578588c896-rsp9w",
 "generateName": "dex-578588c896-",
 "namespace": "default",
 "selfLink": "/api/v1/namespaces/default/pods/dex-578588c896-rsp9w",

成功

把tocken加入到证书中

最简单的方式：

[root@master2 dex]# cat ~/.kube/config apiVersion: v1 clusters: - cluster: certificate-authority-data: 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 server: https://172.31.244.238:6443 name: kubernetes contexts: - context: cluster: kubernetes user: kubernetes-admin name: kubernetes-admin@kubernetes current-context: kubernetes-admin@kubernetes kind: Config preferences: {} users: - name: kubernetes-admin user: token: eyJhbGciOiJSUzI1NiIsImtpZCI6ImJjOTU0NjdlM2I0OTE5YWE1OTEzZDNkMDU3NGM2ZTRjYjBjY2NhNzgifQ.eyJpc3MiOiJodHRwczovLzQ3LjUyLjE5Ny4xNjM6MzIwMDAiLCJzdWIiOiJDZ2M0T1RFeU5UVTNFZ1puYVhSb2RXSSIsImF1ZCI6ImV4YW1wbGUtYXBwIiwiZXhwIjoxNTIzOTY3NDQzLCJpYXQiOjE1MjM4ODEwNDMsImF0X2hhc2giOiJMUzNKUVpiWDVuVnBuam5zSU5nNGZnIiwiZW1haWwiOiJmaHRqb2JAaG90bWFpbC5jb20iLCJlbWFpbF92ZXJpZmllZCI6dHJ1ZSwibmFtZSI6InN0ZXZlbiJ9.KjKSkqqX1I21rkqF4t39x8YmEFx2yPlQSMFInVeAp4lCRACljMvTY07GSWycEez0SarPtO80dTqcM4buz7WMVPMRuSqg-HuCPB3DjzD4M84OiHZSFB_5xOJIUqP0dWLAuPTalu2T-le4Gp0gPXc863YfLEMzRm8cxbvdASwQrTZ5oKgoRVznDREW3NIgEONUU9A64bBeWi5xH1eyCbvh4l3Q-ZfkYG4A4w46FwAmfL4ClxCBiIkpZWhKv5GcN8bg7-msaNlvlejpvbSuVWpt5CLJzpCXHh1AqCUBkXzp8ObSGGIw1BfkVFnyH26bpho2kAzxbGtdwNx4TdGlu_XYlw

注意把user那的client-certificate-data client-key-data 删掉，加上token, 我这直接在/etc/kubernetes/admin.conf上修改的，也可以重新生成配置文件：

kubectl config set-credentials fanux \
--client-certificate=/etc/kubernetes/pki/ca.crt \ --client-key=/etc/kubernetes/pki/ca.key \ --token=eyJhbGciOiJSUzI1NiIsImtpZCI6ImJjOTU0NjdlM2I0OTE5YWE1OTEzZDNkMDU3NGM2ZTRjYjBjY2NhNzgifQ.eyJpc3MiOiJodHRwczovLzQ3LjUyLjE5Ny4xNjM6MzIwMDAiLCJzdWIiOiJDZ2M0T1RFeU5UVTNFZ1puYVhSb2RXSSIsImF1ZCI6ImV4YW1wbGUtYXBwIiwiZXhwIjoxNTIzOTYyNjUyLCJpYXQiOjE1MjM4NzYyNTIsImF0X2hhc2giOiJFUXRWWm5ObE50c2hhWERfZ3N2UkNBIiwiZW1haWwiOiJmaHRqb2JAaG90bWFpbC5jb20iLCJlbWFpbF92ZXJpZmllZCI6dHJ1ZSwibmFtZSI6InN0ZXZlbiJ9.vu0keGMoRGg6OAYpMZNN9zm4pnKXGyXDkZaRNj6MXDY9XsfnBDT4HnXkY17Lvm1ow0xPbq9cgVL3JBZT73jiddgFNAIXJffHfPejlVRSqXx9iF1uEcNIc5tDA1hUPtBrX8n_rzdz0sZsPMb4ZYMx3AdEylszpVrS_OelbB4I_2eLfO0KzwcEknOgV8cZZghCCITl6ZTOeeWEv5FPvJjRC2rpu_MkSY5tAf30SITwldFUMgF8ei3aPrZdojPLgqUWtxKaDmPpcHVLhYr0sLE_BnDZLjGP4ff8l5yy_EfDc7sQsrJR7StwZXRnK-n2omqaV3z-n5IxaUty85e_97FA1g \ --embed-certs=true \ --kubeconfig=fanux.config

kubectl config set-context kubernetes \
--cluster=kubernetes \ --user=fanux \ --namespace=default \ --kubeconfig=fanux.config

kubectl config use-context kubernetes --kubeconfig=fanux.config

kubectl config set-cluster kubernetes --server=https://172.31.244.238:6443 --certificate-authority=/etc/kubernetes/pki/ca.key --kubeconfig=fanux.config

验证：

$ kubectl get pod #正常

删除角色绑定再执行get pod

[root@master2 dex]# kubectl delete -f examples/k8s/role.yaml
clusterrolebinding.rbac.authorization.k8s.io "read-secrets-global" deleted
[root@master2 dex]# kubectl get pod
Error from server (Forbidden): pods is forbidden: User "fhtjob@hotmail.com" cannot list pods in the namespace "default"

已经无权限了。
至于给用户分配更细的权限，比较简单，读者门自己倒持去吧

本文转自SegmentFault-kubernetes认证，对接第三方认证系统，对接github认证