💡
failed to load Kubelet config file /var/lib/kubelet/
config.yaml, e
rror failed to read kubelet config file "/var/lib/kubelet/config.yaml",
error: open /var/lib/kubelet/config.yaml: no such file or directory
--pod-network-cidr : pod의 네트워크, 즉 컨테이너의 서브넷을 지정하는 옵션 (docker 설치 시 기본적으로 지정되는 서브넷은 172.17.0.0/16)
[init] Using Kubernetes version: v1.20.4
[preflight] Running pre-flight checks
[WARNING Firewalld]: firewalld is active, please ensure ports [6443 10250] are open or your cluster may not function correctly
[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: 20.10.5. Latest validated version: 19.03
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [control kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.192.200]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [control localhost] and IPs [192.168.192.200 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [control localhost] and IPs [192.168.192.200 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s[kubelet-check] Initial timeout of 40s passed.
[apiclient] All control plane components are healthy after 64.004842 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.20" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node control as control-plane by adding the labels "node-role.kubernetes.io/master=''" and "node-role.kubernetes.io/control-plane='' (deprecated)"
[mark-control-plane] Marking the node control as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: pxh9uj.gr3wlmzqswixc04m
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
💡
후속 지시 사항 확인
일반계정으로서 kubectl 명령어를 수행하기 위해서 홈 디렉토리 안에 conf 파일을 복사하여 소유권 설정하기 필요
해당 설정을 하지 않고 kubectl 을 사용하면 거부된다.
클러스터에
pod network 플러그인을
추가
해야 한다 : 다양한 오픈소스 플러그인이 있다.
# This section includes base Calico installation configuration.
# For more information, see: https://docs.projectcalico.org/v3.18/reference/installation/api#operator.tigera.io/v1.Installation
apiVersion: operator.tigera.io/v1
kind: Installation
metadata:
name: default
spec:
# Configures Calico networking.
calicoNetwork:
# Note: The ipPools section cannot be modified post-install.
ipPools:
- blockSize: 26
cidr: 192.168.0.0/16 "해당부분 수정 필요"
encapsulation: VXLANCrossSubnet
natOutgoing: Enabled
nodeSelector: all()
💡 이렇게 수정할거면 뭐하러 pod-network-cidr를 따로 옵션으로 지정을 했는지?
현재 가상서버 위에서 쿠버네티스를 돌리고 있는데, 가상서버의 서브넷과 pod의 서브넷이 일치하게 된다.
이렇게 일치하게 되면, pod 내에서 외부로 서비스를 제공하게 될 때 아웃바운드 관련 오류가 날 수 있기 때문에
Master 노드의 taint를 삭제하여 Master 위에 pod를 올릴 수 있게 설정한다. (조그만 클러스터를 꾸리고 있는 경우 추천)
[kube@node1 ~]$ sudo kubeadm join 192.168.192.200:6443 --token pxh9uj.gr3wlmzqswixc04m --discovery-token-ca-cert-hash sha256:50c4ec1a3297c25a34c7d19765fc57c199e3b6406b5e6fde0a331c9e24c43a7f
[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: 20.10.5. Latest validated version: 19.03
[WARNING Service-Kubelet]: kubelet service is not enabled, please run 'systemctl enable kubelet.service'
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
조금 시간이 지난 뒤, get nodes를 하면 READY 상태를 확인할 수 있다.
kubeadm init
This command initializes a Kubernetes control-plane node. Synopsis Run this command in order to set up the Kubernetes control plane The "init" command executes the following phases: preflight Run pre-flight checks certs Certificate generation /ca Generate
kubernetes.io
kubectl 치트 시트
이 페이지는 일반적으로 사용하는 kubectl 커맨드와 플래그에 대한 목록을 포함한다. Kubectl 자동 완성 BASH source <(kubectl completion bash) # bash-completion 패키지를 먼저 설치한 후, bash의 자동 완성을 현재
현재, --cgroup-driver 옵션은 비추, 관련 환경변수 파일이나 설정 파일(var/lib/kubelet/kubeadm-flags.env or /etc/default/kubelet(/etc/sysconfig/kubelet) 은 삭제하고 KubeletConfiguration 야믈 파일을 활용하자
cgroup 관련 설정? 왜 필요?
도커를 사용할 때, kubeadm 은 자동으로 kubelet을 위한 cgoup driver을 감지하고
이를 runtime 동안 /var/lib/kubelet/config.yaml 파일에 set한다.
만약에 다른 CRI를 사용한다면 cgroupDriver 값을 kubeadm init에 넘겨주어야 한다
