git clone https://github.com/kubernetes/kubernetes/
cd ./kubernetes
git log -p

staging/src/k8s.io/apimachinery/pkg/util/proxy/upgradeaware.go

// getResponseCode reads a http response from the given reader, returns the status code,
// the bytes read from the reader, and any error encountered
func getResponseCode(r io.Reader) (int, []byte, error) {
    rawResponse := bytes.NewBuffer(make([]byte, 0, 256))
    // Save the bytes read while reading the response headers into the rawResponse buffer
    resp, err := http.ReadResponse(bufio.NewReader(io.TeeReader(r, rawResponse)), nil)
    if err != nil {
        return 0, nil, err
    }
    // return the http status code and the raw bytes consumed from the reader in the process
    return resp.StatusCode, rawResponse.Bytes(), nil
}

// determine the http response code from the backend by reading from rawResponse+backendConn
rawResponseCode, headerBytes, err := getResponseCode(io.MultiReader(bytes.NewReader(rawResponse), backendConn))
if err != nil {
    glog.V(6).Infof("Proxy connection error: %v", err)
    h.Responder.Error(w, req, err)
    return true
}
if len(headerBytes) > len(rawResponse) {
    // we read beyond the bytes stored in rawResponse, update rawResponse to the full set of bytes read from the backend
    rawResponse = headerBytes
}

if rawResponseCode != http.StatusSwitchingProtocols {
    // If the backend did not upgrade the request, finish echoing the response from the backend to the client and return, closing the connection.
    glog.V(6).Infof("Proxy upgrade error, status code %d", rawResponseCode)
    _, err := io.Copy(requestHijackedConn, backendConn)
    if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
        glog.Errorf("Error proxying data from backend to client: %v", err)
    }
    // Indicate we handled the request
    return true
}

https://github.com/kubernetes/kubernetes/commit/0535bcef95a33855f0a722c8cd822c663fc6275e

192.168.127.80:6443
GET /api/v1/namespaces/role/pods/test1/exec?command=bash&stderr=true&stdin=true&stdout=true&tty=true HTTP/1.1
Host: 192.168.127.80:6443
Authorization: Bearer 1234567890
Connection: upgrade
Upgrade: websocket

192.168.127.80:6443
GET /api/v1/namespaces/role/pods/test1/exec HTTP/1.1
Host: 192.168.127.80:6443
Authorization: Bearer 1234567890
Connection: upgrade
Upgrade: websocket

HTTP/1.1 400 Bad Request
Date: Fri, 07 Dec 2018 08:28:34 GMT
Content-Length: 52
Content-Type: text/plain; charset=utf-8

you must specify at least 1 of stdin, stdout, stderr

GET /api/v1/namespaces/kube-system/pods/kube-flannel-ds-amd64-v2kgb/exec?command=/bin/hostname&input=1&output=1&tty=0 HTTP/1.1
Upgrade: websocket
Connection: Upgrade
Host: 192.168.127.80:6443
Origin: http://192.168.127.80:6443
Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==
Sec-WebSocket-Version: 13

HTTP/1.1 404 Not Found
Content-Type: text/plain; charset=utf-8
X-Content-Type-Options: nosniff
Date: Fri, 07 Dec 2018 13:14:50 GMT
Content-Length: 19

404 page not found

GET /exec/kube-system/kube-flannel-ds-amd64-v2kgb/kube-flannel?command=/bin/hostname&input=1&output=1&tty=0 HTTP/1.1
Upgrade: websocket
Connection: Upgrade
Host: 192.168.127.80:6443
Origin: http://192.168.127.80:6443
Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==
Sec-WebSocket-Version: 13

HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: HSmrc0sMlYUkAGmm5OPpG2HaGWk=
Sec-WebSocket-Protocol: v4.channel.k8s.io


?pegasus03?#{"metadata":{},"status":"Success"}??

GET /runningpods/ HTTP/1.1
Upgrade: websocket
Connection: Upgrade
Host: 192.168.127.80:6443
Origin: http://192.168.127.80:6443
Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==
Sec-WebSocket-Version: 13

{"kind":"PodList","apiVersion":"v1","metadata":{},"items":[{"metadata":{"name":"test1","namespace":"role","uid":"f99e2d0a-f907-11e8-8fb9-000c290f37a1","creationTimestamp":null},"spec":{"containers":[{"name":"test","image":"sha256:17a5ba3b1216ccac0f8ee54568ba256619160ff4020243884bc3ed86bf8ae737","resources":{}}]},"status":{}},{"metadata":{"name":"test","namespace":"role","uid":"d4779abc-f907-11e8-8fb9-000c290f37a1","creationTimestamp":null},"spec":{"containers":[{"name":"test","image":"sha256:17a5ba3b1216ccac0f8ee54568ba256619160ff4020243884bc3ed86bf8ae737","resources":{}}]},"status":{}},{"metadata":{"name":"istio-sidecar-injector-6bd4d9487c-fgkds","namespace":"istio-system","uid":"c4fdf537-f23f-11e8-b2db-000c290f37a1","creationTimestamp":null},...省略

kubectl get namespace
kubectl -n kube-system get pods
kubectl -n kube-system get pods kube-flannel-ds-amd64-48sj8 -o json

HTTP/1.1 404 Not Found
Date: Fri, 07 Dec 2018 14:24:49 GMT
Content-Length: 18
Content-Type: text/plain; charset=utf-8

pod does not exist

1、cd /opt/awesome/role/
2、建一个空间，比如说role
    kubectl create namespace role
3、创建一个pod
    kubectl create -f test_pod.yaml
4、创建RBAC规则，给用户组test赋予了list所有namespaces、在namespace role下list/get pods、在namespace role下get pods/exec的权限
    kubectl create -f test_cluster_role.yaml
    kubectl create -f test_cluster_role_binding.yaml
    kubectl create -f test_role.yaml
    kubectl create -f test_role_binding.yaml
5、创建tokens文件/etc/kubernetes/pki/role-token.csv
6、令apiserver开启token-auth-file
     在/etc/kubernetes/manifests/kube-apiserver.yaml中加一条--token-auth-file=/etc/kubernetes/pki/role-token.csv
7、等待apiserver重启，这时候就可以用使用curl测试下权限配置是否生效了，例如
    curl -k  --header "Authorization: Bearer {你配置的token}" https://192.168.127.80:6443/api/v1/namespaces/role/pods以test-role用户来list在namespace role下的pods

[root@pegasus01 role]# cat test_cluster_role_binding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: test-role
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: test-role
subjects:
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: test

[root@pegasus01 role]# cat test_cluster_role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: test-role
rules:
- apiGroups:
  - ""
  resources:
  - namespaces
  verbs:
  - get
  - list
  - watch

[root@pegasus01 role]# cat test_pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: test
  namespace: role
spec:
  containers:
  - command:
    - /bin/sh
    - -c
    - sleep 36000000
    image: grafana/grafana:5.2.3
    imagePullPolicy: IfNotPresent
    name: test
    resources:
      requests:
        cpu: 10m
  dnsPolicy: ClusterFirst
  priority: 0
  restartPolicy: Always
  schedulerName: default-scheduler
  securityContext: {}
  serviceAccount: default
  serviceAccountName: default
  terminationGracePeriodSeconds: 30

[root@pegasus01 role]# cat test_role_binding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: test-role
  namespace: role
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: test-role
subjects:
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: test

[root@pegasus01 role]# cat test_role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: test-role
  namespace: role
rules:
- apiGroups:
  - ""
  resources:
  - configmaps
  verbs:
  - get
  - list
  - delete
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get
  - list
  - delete
  - watch
- apiGroups:
  - ""
  resources:
  - pods/exec
  verbs:
  - create
  - get

[root@pegasus01 role]# cat /etc/kubernetes/pki/role-token.csv
1234567890,test-role,test-role,test

GET / HTTP/1.1
Upgrade: websocket
Connection: Upgrade
Host: example.com
Origin: http://example.com
Sec-WebSocket-Key: sN9cRrP/n9NdMgdcy2VJFQ==
Sec-WebSocket-Version: 13

HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: fFBooB7FAkLlXgRSz0BT3v4hq5s=
Sec-WebSocket-Location: ws://example.com/

Connection必须设置Upgrade，表示客户端希望连接升级。
Upgrade字段必须设置Websocket，表示希望升级到Websocket协议。
Sec-WebSocket-Key是随机的字符串，服务器端会用这些数据来构造出一个SHA-1的信息摘要。把“Sec-WebSocket-Key”加上一个特殊字符串“258EAFA5-E914-47DA-95CA-C5AB0DC85B11”，然后计算SHA-1摘要，之后进行BASE-64编码，将结果做为“Sec-WebSocket-Accept”头的值，返回给客户端。如此操作，可以尽量避免普通HTTP请求被误认为Websocket协议。
Sec-WebSocket-Version 表示支持的Websocket版本。RFC6455要求使用的版本是13，之前草案的版本均应当弃用。
Origin字段是可选的，通常用来表示在浏览器中发起此Websocket连接所在的页面，类似于Referer。但是，与Referer不同的是，Origin只包含了协议和主机名称。
其他一些定义在HTTP协议中的字段，如Cookie等，也可以在Websocket中使用。