can't deploy kindnet outside of kind

It seems kindnet can work only in kind clusters? can we use it as a standalone cni like calico or flannel?

I just installed kindnet on k3s, it gives this error

Defaulted container "kindnet-cni" out of: kindnet-cni, install-cni-bin (init)
I1221 13:01:31.319885       1 main.go:78] hostIP = 10.1.199.96
podIP = 10.1.199.96
I1221 13:01:31.320158       1 main.go:87] setting mtu 0 for CNI 
I1221 13:01:31.320163       1 main.go:89] Failed to get MTU size from interface eth0, using kernel default MTU size error:Found no eth0 device
I1221 13:01:31.320172       1 main.go:105] Configuring CNI path: /etc/cni/net.d/10-kindnet.conflist bridge: true disableOffload: false mtu: 0
ERROR: configmaps "kubeadm-config" not found
ERROR: configmaps "kube-proxy" not found
panic: Cluster CIDR is not defined

goroutine 1 [running]:
main.main()
	/src/cmd/kindnetd/main.go:119 +0xdd9

ERROR: configmaps "kubeadm-config" not found
ERROR: configmaps "kube-proxy" not found

Those come from kubeadm, and are used to discover cluster networking configuration.
You can set some legacy environment variables instead.

kindnet/cmd/kindnetd/subnets.go

Lines 74 to 75 in b5a3f87

    
           // check for environment variables (legacy) 
        
           podSubnetEnv := os.Getenv("POD_SUBNET")

kubeadm aside, kindnet aims to support Kubernetes, k3s may not work.

What Ben says

	// check for environment variables (legacy)
	podSubnetEnv := os.Getenv("POD_SUBNET")