Kubernetes:端口转发后,我可以通过 "localhost" 但不能通过 "hostname" 访问服务

Kubernetes: After port-forwarding, I can access a service via "localhost" but not via "hostname"

对于这个问题末尾的 main.go 代码,我 运行 以下命令 运行 它在 kubernetes 安装(在 PC):

  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,我确认该服务是 LISTENing:

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

但这就是我的问题,注意到 localhost 成功,hostname -- vps10 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

从上面看来,问题似乎是该服务仅通过 loopback 接口进行侦听,如果这确实是问题所在,我该怎么做才能让它在 [=28= 上进行侦听](或在我指定的 specific interface 上)。我不是 kubernetesgo 专家(这个例子实际上来自一本书=:)),所以如果需要请提供命令。提前致谢!

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))
}

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

默认仅转发本地主机。