Question

我有一个Pod偶尔需要通过自己的主机名调用自己。我有一个部署设置，最终创建Pod和服务到位。我能够使用群集中不同Pod的服务名称，但Pod无法使用其主机名调用自身。这适用于使用Kubernetes 1.5.3版本的Minikube v0.17.1，但升级Minikube或Kubernetes版本似乎打破了局面。这也适用于我们的部署/服务器版本的Kubernetes。

在我的Pod /服务设置中，我需要考虑一些变化吗？我该如何解决这个问题？

事情应如何运作

运行Minikube版本0.17.1：

启动Minikube：

$ minikube start
Starting local Kubernetes cluster...
Starting VM...
SSH-ing files into VM...
Setting up certs...
Starting cluster components...
Connecting to cluster...
Setting up kubeconfig...
Kubectl is now configured to use the cluster.

$ kubectl version
Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"08e099554f3c31f6e6f07b448ab3ed78d0520507", GitTreeState:"clean", BuildDate:"2017-01-12T04:57:25Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"windows/amd64"}
Server Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.3", GitCommit:"029c3a408176b55c30846f0faedf56aae5992e9b", GitTreeState:"clean", BuildDate:"1970-01-01T00:00:00Z", GoVersion:"go1.7.3", Compiler:"gc", Platform:"linux/amd64"}

$ minikube version
minikube version: v0.17.1

部署最少的测试图像（下面的yaml定义）：

kubectl apply -f deploy_python.yaml

执行python2映像，并验证与python映像的连接：

$ kubectl exec -it python2-1281934109-k015g bash
root@python2-1281934109-k015g:/# curl python:12345 --connect-timeout 10
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Directory listing for /</title>
</head>
<body>
<h1>Directory listing for /</h1>
<hr>
<ul>
<li><a href=".dockerenv">.dockerenv</a></li>
<li><a href="bin/">bin/</a></li>
<li><a href="boot/">boot/</a></li>
<li><a href="dev/">dev/</a></li>
<li><a href="etc/">etc/</a></li>
<li><a href="home/">home/</a></li>
<li><a href="lib/">lib/</a></li>
<li><a href="lib64/">lib64/</a></li>
<li><a href="media/">media/</a></li>
<li><a href="mnt/">mnt/</a></li>
<li><a href="opt/">opt/</a></li>
<li><a href="proc/">proc/</a></li>
<li><a href="root/">root/</a></li>
<li><a href="run/">run/</a></li>
<li><a href="sbin/">sbin/</a></li>
<li><a href="srv/">srv/</a></li>
<li><a href="sys/">sys/</a></li>
<li><a href="tmp/">tmp/</a></li>
<li><a href="usr/">usr/</a></li>
<li><a href="var/">var/</a></li>
</ul>
<hr>
</body>
</html>

执行python图像并验证与self的连接：

$ kubectl exec -it python-2555691705-5j0f9 bash
root@python-2555691705-5j0f9:/# curl python:12345 --connect-timeout 10
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Directory listing for /</title>
</head>
<body>
<h1>Directory listing for /</h1>
<hr>
<ul>
<li><a href=".dockerenv">.dockerenv</a></li>
<li><a href="bin/">bin/</a></li>
<li><a href="boot/">boot/</a></li>
<li><a href="dev/">dev/</a></li>
<li><a href="etc/">etc/</a></li>
<li><a href="home/">home/</a></li>
<li><a href="lib/">lib/</a></li>
<li><a href="lib64/">lib64/</a></li>
<li><a href="media/">media/</a></li>
<li><a href="mnt/">mnt/</a></li>
<li><a href="opt/">opt/</a></li>
<li><a href="proc/">proc/</a></li>
<li><a href="root/">root/</a></li>
<li><a href="run/">run/</a></li>
<li><a href="sbin/">sbin/</a></li>
<li><a href="srv/">srv/</a></li>
<li><a href="sys/">sys/</a></li>
<li><a href="tmp/">tmp/</a></li>
<li><a href="usr/">usr/</a></li>
<li><a href="var/">var/</a></li>
</ul>
<hr>
</body>
</html>

这是成功的。通过创建部署和服务，我能够从群集中的任何其他Pod向引用的Pod发出请求。

它在较新版本中的工作方式

（停止并删除正在运行的Minikube。）
启动Minikube，指定Kubernetes版本1.7.0：

$ minikube start --kubernetes-version=v1.7.0
Starting local Kubernetes cluster...
Starting VM...
SSH-ing files into VM...
Downloading localkube binary
137.48 MB / 137.48 MB [============================================] 100.00% 0s
Setting up certs...
Starting cluster components...
Connecting to cluster...
Setting up kubeconfig...
Kubectl is now configured to use the cluster.

$ kubectl version
Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"08e099554f3c31f6e6f07b448ab3ed78d0520507", GitTreeState:"clean", BuildDate:"2017-01-12T04:57:25Z", GoVersion:"go1.7.4", Compiler:"gc", Platform:"windows/amd64"}
Server Version: version.Info{Major:"1", Minor:"7", GitVersion:"v1.7.0", GitCommit:"d3ada0119e776222f11ec7945e6d860061339aad", GitTreeState:"clean", BuildDate:"2017-06-30T10:17:58Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}

部署最少的测试图像（下面的yaml定义）：

$ kubectl apply -f deploy_python.yaml
service "python" created
deployment "python" created
deployment "python2" created

执行python 2图像，并验证与python图像的连接：

$ kubectl exec -it python2-380393367-ztgkq bash
root@python2-380393367-ztgkq:/# curl python:12345 --connect-timeout 10
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Directory listing for /</title>
</head>
<body>
<h1>Directory listing for /</h1>
<hr>
<ul>
<li><a href=".dockerenv">.dockerenv</a></li>
<li><a href="bin/">bin/</a></li>
<li><a href="boot/">boot/</a></li>
<li><a href="dev/">dev/</a></li>
<li><a href="etc/">etc/</a></li>
<li><a href="home/">home/</a></li>
<li><a href="lib/">lib/</a></li>
<li><a href="lib64/">lib64/</a></li>
<li><a href="media/">media/</a></li>
<li><a href="mnt/">mnt/</a></li>
<li><a href="opt/">opt/</a></li>
<li><a href="proc/">proc/</a></li>
<li><a href="root/">root/</a></li>
<li><a href="run/">run/</a></li>
<li><a href="sbin/">sbin/</a></li>
<li><a href="srv/">srv/</a></li>
<li><a href="sys/">sys/</a></li>
<li><a href="tmp/">tmp/</a></li>
<li><a href="usr/">usr/</a></li>
<li><a href="var/">var/</a></li>
</ul>
<hr>
</body>
</html>

执行python图像并尝试连接到self：

$ kubectl exec -it python-2168884431-gls2j bash
root@python-2168884431-gls2j:/# curl python:12345 --connect-timeout 10
curl: (28) Connection timed out after 10000 milliseconds

Yaml文件，deploy_python.yaml：

---
apiVersion: v1
kind: Service
metadata:
  name: python
spec:
  selector:
    app: python
  ports:
  - port: 12345
    targetPort: 12345
    name: http
---    
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: python
  labels:
    app: python
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: python
    spec:
      containers:
      - image: python
        name: python
        command: ["python"]
        args: ["-m", "http.server", "12345" ]
        ports:
        - containerPort: 12345
---    
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: python2
  labels:
    app: python2
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: python2
    spec:
      containers:
      - image: python
        name: python2
        command: ["python"]
        args: ["-m", "http.server", "12345" ]
        ports:
        - containerPort: 12345

Answer 1

这是kubernetes / minikube较新版本中的已知错误，现在正在跟踪：

https://github.com/kubernetes/kubernetes/issues/20475

当前接受的解决方法（https://github.com/kubernetes/kubernetes/issues/20475#issuecomment-190995739）是ssh到你的minikube vm并运行一个特定的ip link命令。

minikube ssh
sudo ip link set docker0 promisc on

我已经测试了这种解决方法，它似乎对我有用。

较新版本的Minikube不允许Pod使用自己的服务

事情应如何运作

它在较新版本中的工作方式

1 个答案: