k3s: K3s Cluster created with weave don't have CNI loopback driver

Describe the bug Similar to #596 on rke. After installed weave, coredns complains about missing loopback driver in /opt/cni/bin.

E0311 21:19:12.004535     823 kuberuntime_manager.go:677] createPodSandbox for pod "coredns-7748f7f6df-8nzpj_kube-system(fe57b2c2-4437-11e9-b3ee-b827ebd31783)" failed: rpc error: code = Unknown desc = failed to setup network for sandbox "2938859438754e66cfa02804b9d857b029f1876cdc898879ad9d6a8abe0b221e": failed to find plugin "loopback" in path [/opt/cni/bin]

To Reproduce

$ sudo k3s server --disable-agent --no-deploy traefik --container-runtime-endpoint=/run/crio/crio.sock
$ sudo k3s agent --no-flannel --server https://192.168.1.6:6443 --token $(sudo cat /var/lib/rancher/k3s/server/node-token)
$ k3s kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(k3s kubectl version | base64 | tr -d '\n')"

Expected behavior

All CNI drivers for the network

About this issue

Original URL
State: closed
Created 5 years ago
Reactions: 4
Comments: 16 (3 by maintainers)

Most upvoted comments

Ah I see, yes. We don’t put them in /opt/cni/bin, they’re in /var/lib/rancher/k3s/data/current/bin alongside all our other userspace binaries. Our packaged flannel is configured to look there automatically, so if you install your own CNI you will need to grab the plugins yourself or point it at the correct path to find ours.

brandond on May 6, 2021

Faced the same

# curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="--flannel-backend=none" sh -

In logs

Feb 12 03:24:55 k3s k3s[23604]: E0212 03:24:55.574053   23604 kuberuntime_sandbox.go:68] CreatePodSandbox for pod "metrics-server-6d684c7b5-vv2mm_kube-system(5fab9e22-de2c-4479-857d-a6412e512f1a)" failed: rpc error: code = Unknown desc = failed to setup network for sandbox "43f447fbd5eb66179b399f34902c83777c848e9ce0c0ed541d3155f81e583f9c": failed to find plugin "loopback" in path [/opt/cni/bin]

I had to manually install files from https://github.com/containernetworking/plugins/releases/download/v0.6.0/cni-plugins-amd64-v0.6.0.tgz

non7top on Feb 12, 2020

As a workaround, this is working : https://github.com/kubernetes-sigs/cri-o/blob/master/tutorial.md#cni-plugins

de13 on Mar 11, 2019