Kubeadm: “ kubeadm重置”间歇性挂起

错误报告：

我看到kubeadm版本1.7有时会永远挂在

[reset] Removing kubernetes-managed containers

我能够在5次中重现此问题4次，并且必须按CTRL+C退出。

$ sudo kubeadm reset
sudo: unable to resolve host vhosakot-aci-1-w9c2681796d
[preflight] Running pre-flight checks
[reset] Stopping the kubelet service
[reset] Unmounting mounted directories in "/var/lib/kubelet"
[reset] Removing kubernetes-managed containers
^C  <--- Pressed CTRL+C to exit
$

通过执行sudo systemctl restart docker.service重新启动Docker可解决此问题，并且sudo kubeadm reset可以正常工作而不会出现问题。

如果在删除kubernetes管理的容器时kubeadm reset检查docker的运行状况，并且如果docker处于不正常状态则超时，而不是永远挂在：

[reset] Removing kubernetes-managed containers

kubeadm版本：

$ kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"7", GitVersion:"v1.7.11", GitCommit:"b13f2fd682d56eab7a6a2b5a1cab1a3d2c8bdd55", GitTreeState:"clean", BuildDate:"2017-11-25T17:51:39Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}

环境：

• Kubernetes版本：

$ kubectl version
Client Version: version.Info{Major:"1", Minor:"7", GitVersion:"v1.7.11", GitCommit:"b13f2fd682d56eab7a6a2b5a1cab1a3d2c8bdd55", GitTreeState:"clean", BuildDate:"2017-11-25T18:34:52Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"7", GitVersion:"v1.7.12", GitCommit:"3bda299a6414b4866f179921610d6738206a18fe", GitTreeState:"clean", BuildDate:"2017-12-29T08:39:49Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}

• 操作系统：
  Ubuntu xenial VM：

$ sudo cat /etc/os-release
sudo: unable to resolve host vhosakot-aci-1-m3710102e28
NAME="Ubuntu"
VERSION="16.04.3 LTS (Xenial Xerus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 16.04.3 LTS"
VERSION_ID="16.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
VERSION_CODENAME=xenial
UBUNTU_CODENAME=xenial

• 内核：

$ uname -a
Linux vhosakot-aci-1-m3710102e28 4.4.0-104-generic #127-Ubuntu SMP Mon Dec 11 12:16:42 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

• 其他：

$ sudo docker info
sudo: unable to resolve host vhosakot-aci-1-w9c2681796d
Containers: 13
 Running: 9
 Paused: 0
 Stopped: 4
Images: 11
Server Version: 1.13.1
Storage Driver: aufs
 Root Dir: /var/lib/docker/aufs
 Backing Filesystem: extfs
 Dirs: 67
 Dirperm1 Supported: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins: 
 Volume: local
 Network: bridge host macvlan null overlay
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version:  (expected: aa8187dbd3b7ad67d8e5e3a15115d3eef43a7ed1)
runc version: N/A (expected: 9df8b306d01f59d3a8029be411de015b7304dd8f)
init version: N/A (expected: 949e6facb77383876aeff8a6944dde66b3089574)
Security Options:
 apparmor
 seccomp
  Profile: default
Kernel Version: 4.4.0-104-generic
Operating System: Ubuntu 16.04.3 LTS
OSType: linux
Architecture: x86_64
CPUs: 3
Total Memory: 15.67 GiB
Name: vhosakot-aci-1-w9c2681796d
ID: X3ES:DTHR:RVNF:6OCE:2UXA:5VKA:LVVS:2G4K:KYHN:EBQZ:QH4C:SIQB
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
WARNING: No swap limit support
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

$ sudo docker version
sudo: unable to resolve host vhosakot-aci-1-w9c2681796d
Client:
 Version:      1.13.1
 API version:  1.26
 Go version:   go1.6.2
 Git commit:   092cba3
 Built:        Thu Nov  2 20:40:23 2017
 OS/Arch:      linux/amd64

Server:
 Version:      1.13.1
 API version:  1.26 (minimum version 1.12)
 Go version:   go1.6.2
 Git commit:   092cba3
 Built:        Thu Nov  2 20:40:23 2017
 OS/Arch:      linux/amd64
 Experimental: false

发生了什么？

kubeadm reset永远挂起。

您预期会发生什么？

如果docker处于不健康状态，则kubeadm reset超时。

如何重现（尽可能少且精确）？

请参阅上面的步骤。