kubernetes使用kubeadm安装集群环境

生产环境部署
一、环境说明：
1，centos7
2，集群环境需要ntp时钟一致
3，getenforce 0
4，disable firewall

二、主机情况:

k8s-master	k8s-node1	k8s-node1
172.16.0.160	172.16.0.161	172.16.0.162

三、环境准备
1，yum 源配置
在master ,node1,node2主机都配置yum 仓库

kubernetes.repo:

[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg

docker-ce.repo
[docker-ce-stable]
name=Docker CE Stable - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/stable
enabled=1
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-stable-debuginfo]
name=Docker CE Stable - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/stable
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-stable-source]
name=Docker CE Stable - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/stable
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-edge]
name=Docker CE Edge - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/edge
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-edge-debuginfo]
name=Docker CE Edge - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/edge
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-edge-source]
name=Docker CE Edge - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/edge
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-test]
name=Docker CE Test - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/test
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-test-debuginfo]
name=Docker CE Test - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/test
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-test-source]
name=Docker CE Test - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/test
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-nightly]
name=Docker CE Nightly - $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/$basearch/nightly
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-nightly-debuginfo]
name=Docker CE Nightly - Debuginfo $basearch
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/debug-$basearch/nightly
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

[docker-ce-nightly-source]
name=Docker CE Nightly - Sources
baseurl=https://mirrors.aliyun.com/docker-ce/linux/centos/7/source/nightly
enabled=0
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/docker-ce/linux/centos/gpg

四、开始安装
1，master执行以下命令
[root@k8s-master ~]#yum install docker-ce kubectl kubeadm kubelet -y

[root@k8s-master ~]# systemctl daemon-reload
[root@k8s-master ~]# systemctl start docker
[root@k8s-master ~]# docker info

3，确保以下值都为1
[root@k8s-master ~]# cat /proc/sys/net/bridge/bridge-nf-call-ip6tables
1
[root@k8s-master ~]# cat /proc/sys/net/bridge/bridge-nf-call-iptables
1

4，开启自启动
[root@k8s-master ~]#systemctl enable docker
[root@k8s-master ~]#systemctl enable kubelet

5,master 节点初始化
kubeadm init --kubernetes-version=v1.12.1 --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12
由于墙，大多数用户会报错
W0422 16:22:43.268820 11829 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.18.2
[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/
[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'

error execution phase preflight: [preflight] Some fatal errors occurred:
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-apiserver:v1.18.2: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-controller-manager:v1.18.2: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-scheduler:v1.18.2: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-proxy:v1.18.2: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
docker pull mirrorgooglecontainers/kube-apiserver:v1.18.2
, error: exit status 1
docker pull mirrorgooglecontainers/kube-apiserver:v1.18.2
[ERROR ImagePull]: failed to pull image k8s.gcr.io/pause:3.2: output: Error response from daemon: Get https://k8s.gcr.io/docker pull mirrorgooglecontainers/kube-apiserver:v1.18.2
v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
docker pull mirrorgooglecontainers/kube-apiserver:v1.18.2
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/etcd:3.4.3-0: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/coredns:1.6.7: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 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

解决方案：
使用阿里云的镜像先拉取
https://blog.csdn.net/networken/article/details/84571373
[root@k8s-master ~]#vim k8s.sh
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.18.2
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.18.2
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.18.2
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.18.2
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0
docker pull coredns/coredns:1.6.7

docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.18.2 k8s.gcr.io/kube-proxy:v1.18.2
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.18.2 k8s.gcr.io/kube-scheduler:v1.18.2
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.18.2 k8s.gcr.io/kube-apiserver:v1.18.2
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.18.2 k8s.gcr.io/kube-controller-manager:v1.18.2
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0 k8s.gcr.io/etcd:3.4.3-0
docker tag coredns/coredns:1.6.7 k8s.gcr.io/coredns:1.6.7
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2 k8s.gcr.io/pause:3.2

docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.18.2
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.18.2
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.18.2
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.18.2
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0
docker rmi coredns/coredns:1.6.7

[root@k8s-master ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-proxy v1.18.2 0d40868643c6 5 days ago 117MB
k8s.gcr.io/kube-apiserver v1.18.2 6ed75ad404bd 5 days ago 173MB
k8s.gcr.io/kube-controller-manager v1.18.2 ace0a8c17ba9 5 days ago 162MB
k8s.gcr.io/kube-scheduler v1.18.2 a3099161e137 5 days ago 95.3MB
k8s.gcr.io/pause 3.2 80d28bedfe5d 2 months ago 683kB
k8s.gcr.io/coredns 1.6.7 67da37a9a360 2 months ago 43.8MB
k8s.gcr.io/etcd 3.4.3-0 303ce5db0e90 5 months ago 288MB

重新初始化
[root@k8s-master ~]# kubeadm init --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12
不报错证明初始化成功

初始化的时候需要保存以下信息用于后续node节点加入master使用

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 172.16.0.160:6443 --token xxxxxxxxxxx \
--discovery-token-ca-cert-hash sha256:xxxxxx

[root@k8s-master ~]# kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-0 Healthy {"health":"true"}

说明master组件启动成功

继续在master开始安装flannel
[root@k8s-master ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds-amd64 created
daemonset.apps/kube-flannel-ds-arm64 created
daemonset.apps/kube-flannel-ds-arm created
daemonset.apps/kube-flannel-ds-ppc64le created
daemonset.apps/kube-flannel-ds-s390x created

[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 16h v1.18.2
[root@k8s-master ~]# kubectl get pods
No resources found in default namespace.
[root@k8s-master ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-66bff467f8-fn8sx 1/1 Running 0 16h
coredns-66bff467f8-k74fn 1/1 Running 0 16h
etcd-k8s-master 1/1 Running 0 16h
kube-apiserver-k8s-master 1/1 Running 0 16h
kube-controller-manager-k8s-master 1/1 Running 0 16h
kube-flannel-ds-amd64-jg7zw 1/1 Running 0 65s
kube-proxy-n5rfj 1/1 Running 0 16h
kube-scheduler-k8s-master 1/1 Running 0 16h

6，初始化node1 node2
首先确保node1 node2安装以下
yum install docker-ce kubeadm kubelet -y
systemctl enable docker
systemctl enable kubelet
7，将node1 ,node2 加入master集群
[root@k8s-node1 ~]# kubeadm join 172.16.0.160:6443 --token xxxx --discovery-token-ca-cert-hash sha256:xxxx
W0423 10:23:35.439522 22002 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[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/
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.18" ConfigMap in the kube-system namespace
[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.

证明加入成功 ，同时node2 也执行相同命令
此时验证
[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 17h v1.18.2
k8s-node1 NotReady 5m44s v1.18.2
k8s-node2 NotReady 25s v1.18.2
这时候显示not ready 说明node还完全成功加入，此时可能正在拉取镜像中，稍等几分钟进行查看

[root@k8s-node1 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
k8s.gcr.io/kube-proxy v1.18.2 0d40868643c6 6 days ago 117MB
quay.io/coreos/flannel v0.12.0-amd64 4e9f801d2217 5 weeks ago 52.8MB
k8s.gcr.io/pause 3.2 80d28bedfe5d 2 months ago

[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 17h v1.18.2
k8s-node1 Ready 11m v1.18.2
k8s-node2 Ready 5m56s v1.18.2
此时证明完全加入成功