Error response from daemon: rpc error: code = Unknown desc = The swarm does not have a leader. It‘s

今天在本机虚拟机用docker stack起eureka的service发现有以下报错：

docker stack depoly -c <ymlname> <servicename>
Error response from daemon: rpc error: code = Unknown desc = The swarm does not have a leader. It's possible that too few managers are online. Make sure more than half of the managers are online.

【原因】这是由于集群中的manager节点出现异常导致的问题
【我的环境】一共三台节点，其中练习手动添加manager节点的时候，添加了两个manager节点，今天只启动了一个manager节点
于是想看一下节点情况,结果又出现了以下报错

docker node ls
Error response from daemon: rpc error: code = Unknown desc = The swarm does not have a leader. It's possible that too few managers are online. Make sure more than half of the managers are online.

解决方法

有以下两种解决办法：

• 重启所有manger节点
• 重新选举出leader后即可恢复正常。

我选择了重新选举

(base) [[email protected] apps]# docker swarm init --force-new-cluster

Swarm initialized: current node (97u9dg2zc8sb6u5hrm68a7a0h) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join --token SWMTKN-1-1nkdxehrdxg46n6b3mnp0j64hzf87k1lvdd3v522klmw5dsqwi-aqg0vj3ihmp2cd8ph0v8zbnpe 192.168.40.128:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

此时再执行docker node ls 就可以了

(base) [[email protected] apps]# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
97u9dg2zc8sb6u5hrm68a7a0h *   master     Ready     Active         Leader           20.10.8
sak742jquzrw0ifd21vqlyllw     slave1     Down      Active                          20.10.7
vt84s64qydcqbq1y94hvkw3yi     slave2     Down      Active                          1.13.1

此时service也可以正常启动了

(base) [[email protected] apps]# docker stack deploy -c eureka.yml eureka
Creating service eureka_eureka

问题解决