Kubernetes:端口转发之后,我可以通过“ localhost”访问服务,而不能通过“主机名”访问

时间:2020-04-01 16:36:25

标签: docker go networking kubernetes portforwarding

对于此问题末尾的main.go代码,我运行了以下命令以在kubernetes安装(在PC上)上运行它:

  1. docker image build -t myID/go-demo:1.2 .

  2. docker image push myID/go-demo:1.2 # Pushed up to DockerHub

  3. kubectl run demo2 --image=myID/go-demo:1.2 --port=19999 --labels app=demo2

  4. kubectl port-forward deploy/demo2 19999:8888

    Forwarding from 127.0.0.1:19999 -> 8888 Forwarding from [::1]:19999 -> 8888

然后,在另一个tmux(1)终端中,我确认服务正在LISTEN上:

user@vps10$ sudo netstat -ntlp | egrep "Local|19999"
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 127.0.0.1:19999         0.0.0.0:*               LISTEN      736786/kubectl      
tcp6       0      0 ::1:19999               :::*                    LISTEN      736786/kubectl

但这是我的问题,注意到localhost的成功和hostname -- vps10的失败:

user@vps10$ curl localhost:19999 # Works.
Hello, 世界

user@vps10$ curl vps10:19999     # Fails.
curl: (7) Failed to connect to vps10 port 19999: Connection refused

从上面看,问题似乎在于该服务仅通过loopback接口进行监听,如果确实存在问题,我该怎么做才能使其在all interfaces上进行监听(或在我指定的specific interface上)。我不是kubernetesgo专家(此示例实际上来自一本书= :)),因此请根据需要提供命令。预先谢谢你!

HTTP服务器代码

package main

import (
        "fmt"
        "log"
        "net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintln(w, "Hello, 世界")
}

func main() {
        http.HandleFunc("/", handler)
        log.Fatal(http.ListenAndServe("0.0.0.0:8888", nil))
}

1 个答案:

答案 0 :(得分:3)

根据kubectl帮助:

 # Listen on port 8888 on all addresses, forwarding to 5000 in the pod
  kubectl port-forward --address 0.0.0.0 pod/mypod 8888:5000

  # Listen on port 8888 on localhost and selected IP, forwarding to 5000 in the pod
  kubectl port-forward --address localhost,10.19.21.23 pod/mypod 8888:5000

默认设置是仅对本地主机转发。