Kubernetes Jenkins插件-奴隶总是离线

Question

我试图使用Jenkins/Kubernetes插件来协调docker奴隶与Jenkins。

我正在使用这个插件：https://github.com/jenkinsci/kubernetes-plugin

我的问题是所有的从机都离线了，所以作业无法执行：

我已经用minikube在我的本地盒子上和我们的ops组托管的K8集群上尝试了这一点。我试过Jenkins1.9和Jenkins2。我总是得到同样的结果。截图来自Jenkins1.642.4，K8 v1.2.0

这是我的配置...请注意，当我单击“测试连接”时，我获得了成功。还要注意，我不需要任何凭据（这是我看到的与文档示例的唯一区别）。

Jenkins日志一遍又一遍地显示了以下内容：

    Waiting for slave to connect (11/100): docker-6b55f1b7fafce
Jul 20, 2016 5:01:06 PM INFO org.csanchez.jenkins.plugins.kubernetes.KubernetesCloud$ProvisioningCallback call
Waiting for slave to connect (12/100): docker-6b55f1b7fafce
Jul 20, 2016 5:01:07 PM INFO org.csanchez.jenkins.plugins.kubernetes.KubernetesCloud$ProvisioningCallback call
Waiting for slave to connect (13/100): docker-6b55f1b7fafce
Jul 20, 2016 5:01:08 PM INFO org.csanchez.jenkins.plugins.kubernetes.KubernetesCloud$ProvisioningCallback call

当我运行Kubectl get events时，我会看到以下内容：

24s         24s        1         docker-6b3c2ff27dad3   Pod                                Normal    Scheduled           {default-scheduler }      Successfully assigned docker-6b3c2ff27dad3 to 96.xxx.xx.159
24s         23s        2         docker-6b3c2ff27dad3   Pod                                Warning   MissingClusterDNS   {kubelet 96.xxx.xx.159}   kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
23s         23s        1         docker-6b3c2ff27dad3   Pod       spec.containers{slave}   Normal    Pulled              {kubelet 96.xxx.xx.159}   Container image "jenkinsci/jnlp-slave" already present on machine
23s         23s        1         docker-6b3c2ff27dad3   Pod       spec.containers{slave}   Normal    Created             {kubelet 96.xxx.xx.159}   Created container with docker id 82fcf1bd0328
23s         23s        1         docker-6b3c2ff27dad3   Pod       spec.containers{slave}   Normal    Started             {kubelet 96.xxx.xx.159}   Started container with docker id 82fcf1bd0328

 ➜  docker git:(master) ✗ kubectl get pods --namespace default -o wide
NAME                   READY     STATUS    RESTARTS   AGE       NODE
docker-6bb647254a2a4   1/1       Running   0          1m        96.x.x.159

➜  docker git:(master) ✗ kubectl log docker-6bafbac10b392

    Jul 20, 2016 6:45:10 PM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connecting to 96.x.x.159:50000 (retrying:10)
java.net.ConnectException: Connection refused
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)

Answer 1

在Kubernetes中运行jenkins时，服务名称可以由jenkins主服务器和从服务器解析。

最好的配置方法是使用内部DNS并将jenkins url设置为：

http://jenkins:8080

（假设您调用了服务jenkins，并且服务上的端口是8080）

不需要隧道。

这种方法的好处是，无需重新配置，它将在jenkins的重新启动中幸存下来。

第二个好处是您不必将Jenkins暴露给外部世界，从而限制了安全风险。