kubeadm init 에러 detected "cgroupfs" as the Docker cgroup driver

문제상황

kubeadm으로 클러스터를 구축하려고 진행중이였고, CNI 는 Calico를 사용하려고 했다.

sudo kubeadm init --pod-network-cidr=192.168.0.0/16

그랬더니 다음과 같은 에러를 받았다

I0317 05:54:40.295054   21706 version.go:254] remote version is much newer: v1.26.2; falling back to: stable-1.21
[init] Using Kubernetes version: v1.21.14
[preflight] Running pre-flight checks
	[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at <https://kubernetes.io/docs/setup/cri/>
	[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 23.0.1. Latest validated version: 20.10
error execution phase preflight: [preflight] Some fatal errors occurred:
	[ERROR FileContent--proc-sys-net-ipv4-ip_forward]: /proc/sys/net/ipv4/ip_forward contents are not set to 1
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher

 

에러해결1

Docker cgroup 드라이버가 cgroupfs 로 설정되어있고, 이를 권장드라이버인 systemd로 해결해주어야한다

sudo vi /etc/docker/daemon.json

# 다음 내용 추가
{
  "exec-opts": ["native.cgroupdriver=systemd"]
}

#적용
sudo systemctl restart docker

에러해결2

/proc/sys/net/ipv4/ip_forward 파로 설정되어있지않다.

해당 값은 커널에서 IP 패킷을 전달허용하는데에 지정된 값이다.

sudo sysctl net.ipv4.ip_forward=1