[Error response from daemon: rpc error: code = Unknown desc = constraint expected one operator from ==, !=]

 

Issue:- 

So received the error while deploying the visualizer , specifically for putting the constraint node.role=manager.

Error:- 

[root@managernode ~]# docker service create --name=viz --publish=8080:8080/tcp --constraint==node.role=manager --mount type=bind,src=/var/run/docker.sock,dst=/var/run/docker.sock dockersamples/visualizer

Error response from daemon: rpc error: code = Unknown desc = constraint expected one operator from ==, !=

Resolution:-

You need to use the == beween the node.role==manager in order to solve the problem so the command should be

[root@managernode ~]# docker service create --name=viz --publish=8080:8080/tcp --constraint==node.role==manager --mount type=bind,src=/var/run/docker.sock,dst=/var/run/docker.sock dockersamples/visualizer

Error response from daemon: rpc error: code = Unknown desc = constraint expected one operator from ==, !=