kubernetes安装

1.系统信息

角色	系统	CPU	Core
master	18.04.1-Ubuntu	4	8G
slave	18.04.1-Ubuntu	4	4G

2.安装前准备（主节点和从节点都需要执行）
2.1 关闭swap

sudo swapoff -a

2.2 配置系统安装源和kubernetes安装源
在/etc/apt/sources.list.d/ 追加以下两个文件

deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main

deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted
deb http://mirrors.aliyun.com/ubuntu/ bionic universe
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates universe
deb http://mirrors.aliyun.com/ubuntu/ bionic multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

2.3 安装kubernetes源的安全key

suod curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add -

3.安装主节点
3.1 安装docker
可参考docke install
具体步骤如下
3.1.1 下载安装包
containerd.io_1.2.6-3_amd64.deb
docker-ce-cli_19.03.5_3-0_ubuntu-bionic_amd64.deb
docker-ce_19.03.5_3-0_ubuntu-bionic_amd64.deb

3.1.2 使用 sudo dpkg -i 依次安装上面的三个包

3.1.3 追加docker用户组
sudo groupadd docker
3.1.4 将当前用户追加到docker用户组
sudo usermod -aG docker $USER
3.1.5 使用户组生效
newgrp docker
3.1.6 设置docker开机启动
sudo systemctl enable docker

3.2 安装kubelet组件
3.2.1 获取可安装的kubernetes版本号
apt-cache madison kubeadm
apt-cache madison kubelet
apt-cache madison kubectl

从返回列表中找一个自己要安装的版本号，我们以1.16.3-00为例
3.2.2 执行如下命令，开始安装

sudo apt install -y kubelet=1.16.3-00 kubeadm=1.16.3-00 kubectl=1.16.3-00

3.3 下载相关镜像
使用如下命令获取需要的镜像

chengf@chengf:~$ kubeadm config images list
W1126 21:01:07.767448   20606 version.go:101] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get https://dl.k8s.io/release/stable-1.txt: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
W1126 21:01:07.767516   20606 version.go:102] falling back to the local client version: v1.16.3
k8s.gcr.io/kube-apiserver:v1.16.3
k8s.gcr.io/kube-controller-manager:v1.16.3
k8s.gcr.io/kube-scheduler:v1.16.3
k8s.gcr.io/kube-proxy:v1.16.3
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.3.15-0
k8s.gcr.io/coredns:1.6.2

因为k8s.gcr.io在国内无法访问，所以我们需要提前将这些镜像下载好，并tag成kubernetes需要的镜像名称

chengf@chengf:~$ docker images
REPOSITORY                                TAG                 IMAGE ID            CREATED             SIZE
kubeimage/kube-proxy-amd64                v1.16.3             9b65a0f78b09        13 days ago         86.1MB
k8s.gcr.io/kube-proxy                     v1.16.3             9b65a0f78b09        13 days ago         86.1MB
kubeimage/kube-apiserver-amd64            v1.16.3             df60c7526a3d        13 days ago         217MB
k8s.gcr.io/kube-apiserver                 v1.16.3             df60c7526a3d        13 days ago         217MB
kubeimage/kube-controller-manager-amd64   v1.16.3             bb16442bcd94        13 days ago         163MB
k8s.gcr.io/kube-controller-manager        v1.16.3             bb16442bcd94        13 days ago         163MB
kubeimage/kube-scheduler-amd64            v1.16.3             98fecf43a54f        13 days ago         87.3MB
k8s.gcr.io/kube-scheduler                 v1.16.3             98fecf43a54f        13 days ago         87.3MB
coredns/coredns                           1.6.5               70f311871ae1        2 weeks ago         41.6MB
gcr.azk8s.cn/google_containers/etcd       3.3.15-0            b2756210eeab        2 months ago        247MB
k8s.gcr.io/etcd                           3.3.15-0            b2756210eeab        2 months ago        247MB
coredns/coredns                           1.6.2               bf261d157914        3 months ago        44.1MB
k8s.gcr.io/coredns                        1.6.2               bf261d157914        3 months ago        44.1MB
kubeimage/pause                           3.1                 da86e6ba6ca1        23 months ago       742kB
k8s.gcr.io/pause                          3.1                 da86e6ba6ca1        23 months ago       742kB

3.4 获取默认pod的network范围

chengf@chengf:~$ kubeadm config print init-defaults
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 1.2.3.4
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: chengf
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: k8s.gcr.io
kind: ClusterConfiguration
kubernetesVersion: v1.16.0
networking:
  dnsDomain: cluster.local
  serviceSubnet: 10.96.0.0/12
scheduler: {}

3.5 通过kubeadm init安装master

root@chengf:/etc/kubernetes# kubeadm init --kubernetes-version=v1.16.3 --pod-network-cidr=10.96.0.0/12 --apiserver-advertise-address=192.168.0.107 --node-name=chengf --ignore-preflight-errors=ImagePull
[init] Using Kubernetes version: v1.16.3
[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: 19.03.5. Latest validated version: 18.09
[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'
[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] Activating the kubelet service
[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 [chengf kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.0.107]
[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 [chengf localhost] and IPs [192.168.0.107 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [chengf localhost] and IPs [192.168.0.107 127.0.0.1 ::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
[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
[apiclient] All control plane components are healthy after 17.505256 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.16" 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 chengf as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node chengf as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 7zi6wy.j3mm4fzdyxc0m3bx
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[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
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

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

kubeadm join 192.168.0.107:6443 --token 7zi6wy.j3mm4fzdyxc0m3bx \
    --discovery-token-ca-cert-hash sha256:27e0d9fd7e5e309249cf3a515514e370c230b2115cea5170ec9e5be61c18b2c1

参数说明：

kubernetes-version	版本号
pod-network-cidr	设置上一步骤中获取的IP范围
apiserver-advertise-address	设置成主机IP
node-name	主机名称
ignore-preflight-errors	忽略拉不到镜像的错误

安装过程会有如下警告：
[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: 19.03.5. Latest validated version: 18.09


3.6 按照输出，执行如下命令，使当前普通用户可以执行kuber命令

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

4.安装node
4.1 安装docker（参考3.1）
4.2 安装kubelet kubeadm

sudo apt install -y kubelet=1.16.3-00 kubeadm=1.16.3-00
sudo systemctl enable kubelet && systemctl start kubelet

4.3 将从节点加入集群，执行主节点安装完成后生成的加入命令

sudo kubeadm join 192.168.0.107:6443 --token 7zi6wy.j3mm4fzdyxc0m3bx --discovery-token-ca-cert-hash sha256:27e0d9fd7e5e309249cf3a515514e370c230b2115cea5170ec9e5be61c18b2c1

• 如果加入过程出错了，可以在命令行后面加上 --5来看具体的错误信息
• 看到如下信息证明加入成功
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.

4.4 在master节点上执行

chengf@chengf:~$ kubectl get nodes
NAME     STATUS     ROLES    AGE     VERSION
chengf   NotReady   master   3d23h   v1.16.3
slave    NotReady   <none>   2m43s   v1.16.3

发下master为NotReady，这是因为还没有安装CNI网络插件，现在安装下，具体CNI可参考
CNI,本例选择weave
5，在主节点执行
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version| base64 | tr -d  '\n')"

执行时报错，
chengf@chengf:~$ kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version| base64 | tr -d  '\n')"
Unable to connect to the server: net/http: TLS handshake timeout

分成三步做
（1）获取version

chengf@chengf:~$ kubectl version | base64 | tr -d '\n'
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

（2）从浏览器执行

https://cloud.weave.works/k8s/net?k8s-version=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

执行完会下载下来一个net.yaml,传到服务器上

（3）执行

chengf@chengf:~/soft$ kubectl apply -f net.yaml 
serviceaccount/weave-net created
clusterrole.rbac.authorization.k8s.io/weave-net created
clusterrolebinding.rbac.authorization.k8s.io/weave-net created
role.rbac.authorization.k8s.io/weave-net created
rolebinding.rbac.authorization.k8s.io/weave-net created
daemonset.apps/weave-net created

5.2 再次确认

chengf@chengf:~/soft$ kubectl get nodes
NAME     STATUS     ROLES    AGE     VERSION
chengf   Ready      master   3d23h   v1.16.3
slave    NotReady   <none>   40m     v1.16.3

chengf@chengf:~/soft$ kubectl get pods --all-namespaces
NAMESPACE     NAME                             READY   STATUS              RESTARTS   AGE
kube-system   coredns-5644d7b6d9-gdjwp         1/1     Running             0          3d23h
kube-system   coredns-5644d7b6d9-s9l76         1/1     Running             0          3d23h
kube-system   etcd-chengf                      1/1     Running             0          3d23h
kube-system   kube-apiserver-chengf            1/1     Running             6          3d23h
kube-system   kube-controller-manager-chengf   1/1     Running             6          3d23h
kube-system   kube-proxy-g7f6j                 1/1     Running             0          3d23h
kube-system   kube-proxy-nljf6                 0/1     ContainerCreating   0          42m
kube-system   kube-scheduler-chengf            1/1     Running             7          3d23h
kube-system   weave-net-7zbps                  2/2     Running             0          7m31s
kube-system   weave-net-kt2rz                  0/2     ContainerCreating   0          7m31s

发现weave-net-kt2rz没有启动起来，通过
kubectl --namespace=kube-system describe pod weave-net-kt2rz
命令查看

Failed create pod sandbox: rpc error: code = Unknown desc = failed pulling image "k8s.gcr.io/pause:3.1": Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

是下不下来镜像，这个镜像我们需要在slave节点上下载后tag
chengf@slave:~/soft$ docker pull kubeimage/pause:3.1

3.1: Pulling from kubeimage/pause
Image docker.io/kubeimage/pause:3.1 uses outdated schema1 manifest format. Please upgrade to a schema2 image for better future compatibility. More information at https://docs.docker.com/registry/spec/deprecated-schema-v1/
7675586df687: Pull complete 
Digest: sha256:c780ae1f699e27c67bb6f1ac38f9b0a576a9d22c862aaae0d3549b6000569958
Status: Downloaded newer image for kubeimage/pause:3.1
docker.io/kubeimage/pause:3.1
chengf@slave:~/soft$ docker tag kubeimage/pause:3.1 k8s.gcr.io/pause:3.1

如果还要错误，可以一一排查，直到问题解决

chengf@chengf:~/soft$ kubectl get pods --all-namespaces
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE
kube-system   coredns-5644d7b6d9-gdjwp         1/1     Running   0          3d23h
kube-system   coredns-5644d7b6d9-s9l76         1/1     Running   0          3d23h
kube-system   etcd-chengf                      1/1     Running   0          3d23h
kube-system   kube-apiserver-chengf            1/1     Running   6          3d23h
kube-system   kube-controller-manager-chengf   1/1     Running   6          3d23h
kube-system   kube-proxy-g7f6j                 1/1     Running   0          3d23h
kube-system   kube-proxy-nljf6                 1/1     Running   0          56m
kube-system   kube-scheduler-chengf            1/1     Running   7          3d23h
kube-system   weave-net-7zbps                  2/2     Running   0          21m
kube-system   weave-net-kt2rz                  2/2     Running   6          21m

这样通过kubeadm工具就实现了kubernetes集群的搭建，如果集群安装失败，可以通过kubeadm reset命令恢复主机，之后再重新安装