kubernetes v1.7.1 kubeadm联接主机名"“无法到达错误

Question

今天，在运行kubeadm join --token 189518.c21306e71082d6ec命令时，我用v1.7.1重新创建了集群，它给出了以下错误。这是以前版本的kubernetes所做的工作。在这个版本中有什么变化，我们如何解决这个问题？

[root@k8s17-02 ~]# kubeadm join --token 189518.c21306e71082d6ec 192.168.15.91:6443
[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] WARNING: hostname "" could not be reached
[preflight] WARNING: hostname "" lookup : no such host
[preflight] Some fatal errors occurred:
        hostname "" a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
[preflight] If you know what you are doing, you can skip pre-flight checks with `--skip-preflight-checks`

在7/21/17上的更新

用v1.7.2同样的问题测试了这个问题。

# ./kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"7", GitVersion:"v1.7.2", GitCommit:"922a86cfcd65915a9b2f69f3f193b8907d741d9c", GitTreeState:"clean", BuildDate:"2017-07-21T08:08:00Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}

# ./kubeadm join --token 189518.c21306e71082d6ec 192.168.15.91:6443
[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] WARNING: hostname "" could not be reached
[preflight] WARNING: hostname "" lookup : no such host
[preflight] Some fatal errors occurred:
        hostname "" a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
[preflight] If you know what you are doing, you can skip pre-flight checks with `--skip-preflight-checks`

谢谢SR

Answer 1

看起来它想要查找主机名，但是不能，因为它不在DNS中。有两种方法可以解决这个问题：

1. Kubernetes与命名节点一起工作得更好。虽然这很烦人，但从长远来看，它提供了一些好处，例如在重新启动时必须使用不同的IP地址。您可以在每台机器上编辑/etc/hosts，为集群中的所有框指定名称，或者启动本地DNS，将名称添加到其中。
2. 或者，你可以试着跳过飞行前检查.kubeadm join --skip-preflight-checks --token TOKEN HOST:PORT

Answer 2

根据#49065 GitHub问题，这将在1.7.2中得到修正，在此之前，建议使用--skip-preflight-checks标志。对我起作用了。