节点无法加入群集

Question

我有3个虚拟机。它们都有docker 1.12，并且在centos7上运行。所有端口都已打开，vm可以在我启动集群时相互ping

docker swarm init --advertise-addr 192.168.140.12

Docker信息告诉我：

Swarm: active
 NodeID: 0drcj2nku1mv8t16fxva48edxx
 Is Manager: true
 ClusterID: cchn0yzospwoe1h9f55d7omxx
 Managers: 1
 Nodes: 1

现在，我尝试将节点（其他VM）加入集群。我使用启动管理器后推荐的命令。

docker swarm join \
     --token SWMTKN-1-48ythur5k6ckkz90ttlprw37p9z3ldclws51qirw5wdyfmvevr-3sb2t66b2fj6e4dhmfo1vavxx \
     192.168.140.12:2377

但我得到了：

Error response from daemon: Timeout was reached before node was joined. Attempt to join the cluster will continue in the background. Use "docker info" command to see the current swarm status of your node.

Docker信息告诉我：

Swarm: pending
 NodeID:
 Error: rpc error: code = 1 desc = context canceled
 Is Manager: false
 Node Address: 192.168.140.14

集群管理器：

# netstat -tulpn | grep docker
tcp6       0      0 :::2377                 :::*                    LISTEN      1602/dockerd
tcp6       0      0 :::7946                 :::*                    LISTEN      1602/dockerd
tcp6       0      0 :::8080                 :::*                    LISTEN      3398/docker-proxy
tcp6       0      0 :::32768                :::*                    LISTEN      3199/docker-proxy
tcp6       0      0 :::32769                :::*                    LISTEN      3219/docker-proxy
tcp6       0      0 :::32770                :::*                    LISTEN      3341/docker-proxy
tcp6       0      0 :::32771                :::*                    LISTEN      3436/docker-proxy
tcp6       0      0 :::2375                 :::*                    LISTEN      1602/dockerd
udp6       0      0 :::7946                 :::*                                1602/dockerd

如何调试此问题，或者我是否忘记执行某些重要步骤？服务器之间是否需要ssh访问？谢谢

节点上的日志：

Aug  8 09:50:24 localhost dockerd: time="2016-08-08T09:50:24.393432145-04:00" level=error msg="Handler for POST /v1.24/swarm/leave returned error: This node is not part of swarm"
Aug  8 09:51:01 localhost su: (to root) worker1 on pts/1
Aug  8 09:51:34 localhost dockerd: time="2016-08-08T09:51:34.384408514-04:00" level=error msg="Handler for POST /v1.24/swarm/join returned error: Timeout was reached before node was joined. Attempt to join the cluster will continue in the background. Use \"docker info\" command to see the current swarm status of your node."
Aug  8 09:51:40 localhost su: (to root) worker1 on pts/1
Aug  8 09:52:47 localhost dhclient[1277]: DHCPREQUEST on eno16777736 to 192.168.140.254 port 67 (xid=0x11f8fba8)
Aug  8 09:52:47 localhost dhclient[1277]: DHCPACK from 192.168.140.254 (xid=0x11f8fba8)
Aug  8 09:52:47 localhost NetworkManager[953]: <info>    address 192.168.140.13
Aug  8 09:52:47 localhost NetworkManager[953]: <info>    plen 24 (255.255.255.0)
Aug  8 09:52:47 localhost NetworkManager[953]: <info>    gateway 192.168.140.2
Aug  8 09:52:47 localhost NetworkManager[953]: <info>    server identifier 192.168.140.254
Aug  8 09:52:47 localhost NetworkManager[953]: <info>    lease time 1800
Aug  8 09:52:47 localhost NetworkManager[953]: <info>    nameserver '192.168.140.2'
Aug  8 09:52:47 localhost NetworkManager[953]: <info>    domain name 'localdomain'
Aug  8 09:52:47 localhost NetworkManager[953]: <info>  (eno16777736): DHCPv4 state changed bound -> bound
Aug  8 09:52:47 localhost dbus[878]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service'
Aug  8 09:52:47 localhost dbus-daemon: dbus[878]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service'
Aug  8 09:52:47 localhost systemd: Starting Network Manager Script Dispatcher Service...
Aug  8 09:52:47 localhost dhclient[1277]: bound to 192.168.140.13 -- renewal in 713 seconds.
Aug  8 09:52:47 localhost dbus[878]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Aug  8 09:52:47 localhost dbus-daemon: dbus[878]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Aug  8 09:52:47 localhost nm-dispatcher: Dispatching action 'dhcp4-change' for eno16777736
Aug  8 09:52:47 localhost systemd: Started Network Manager Script Dispatcher Service.

有时警告：

level=warning msg="failed to retrieve remote root CA certificate: rpc error: code = 1 desc = context canceled

Answer 1

正如wenjianhn所解释的，确保您没有在工作节点上为Docker配置http代理（如下所述）。事实上，Swarm节点通过HTTP（默认端口2377）进行通信；因此，如果您配置了http代理，您的工作节点将使用配置的http代理，即使管理器节点位于您的LAN中。

另外，请确保没有防火墙阻止端口2377上的通信：

user@workernode$ telnet ip-of-manager 2377

如果无法打开端口2377上的telnet连接，这意味着此端口被防火墙（工作节点的防火墙或管理器的防火墙）阻止。

Answer 2

我所有虚拟机上的主机名都是：localhost。本地域。我在每台服务器上更改了/etc/hosts中的主机名并重新启动。现在我能够创建我的swarm集群并成功添加节点。

Answer 3

可能您使用的是http代理。

您可以使用以下命令查看dockerd正在做什么。

# strace -Fp `pidof dockerd` 2>&1 |grep -v futex |grep -v epoll_wait |grep -v pselect