Node unable to join Docker Swarm cluster as a worker node

Question

OS: RHEL 7.4

uname -r: 3.10.0-693.el7.x86_64

docker version

Client: Docker Enterprise Edition (EE) 2.0
 Version:       17.06.2-ee-10
 API version:   1.30
 Go version:    go1.8.7
 Git commit:    66261a0
 Built: Fri Apr 27 00:38:41 2018
 OS/Arch:       linux/amd64

Server: Docker Enterprise Edition (EE) 2.0
 Engine:
  Version:      17.06.2-ee-10
  API version:  1.30 (minimum version 1.12)
  Go version:   go1.8.7
  Git commit:   66261a0
  Built:        Fri Apr 27 00:40:03 2018
  OS/Arch:      linux/amd64
  Experimental: false

Error

Kubelet is unhealthy: runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

I am trying to join a node to swarm cluster as a worker node, but I am getting the aforementioned error. Did anyone face this issue?

Expected result should be node must successfully added to the swarm cluster.

Regards Aditya

Answer 1

Error: calico pod is unhealthy

This was due to reverse path filtering variable set to 2. We changed it to 1, and the node was able to join without a problem.

Reverse path filtering is one of the many ways which you can leverage to avert MiTM attacks. As it was set to 2, docker didn’t allow that node to join the cluster until it was set to 1.

Regards

Aditya