安装

需要安装的工具包括：docker-ce、kubeadm、kubectl和kubelet

安装前准备

运行

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install crul

安装docker-ce

这里可以直接使用阿里的脚本

curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun

更换docker源

打开配置文件

sudo gedit /etc/docker/daemon.json

写入以下内容：

{ 
"registry-mirrors": ["https://alzgoonw.mirror.aliyuncs.com"] 
}

重启docker服务

systemctl daemon-reload
systemctl restart docker
systemctl status docker

此部分引用自ubuntu16.04 配置阿里云docker镜像加速器

安装k8s相关组件

由于国内访问一些网站不方便，此处使用国内的源（中科大）进行安装。
1.获取公钥

wget https://raw.githubusercontent.com/EagleChen/kubernetes_init/master/kube_apt_key.gpg

2.添加中科大镜像源

echo "deb [arch=amd64] https://mirrors.ustc.edu.cn/kubernetes/apt kubernetes-$(lsb_release -cs) main"
apt-get update

3.安装k8s先关工具

apt-get install -y kubelet kubeadm kubectl --allow-unauthenticated

这里最好加上--allow-unauthenticated，不然以后所有的相关操作全得加sudo。

初始化节点

下载相关镜像

理论上来说，运行kubeadm init时，工具会自动下载k8s运行所需的镜像，但是由于众所周知的原因，这些镜像无法正常下载。这时需要手动下载相关镜像。

1.查看所需的镜像
由于版本的问题，不同版本的k8s需要的镜像名，版本甚至仓库名都是不一样的，切不可完全照搬其他人或书上的经验，需要自己查看确认需要的镜像情况。
命令行输入获取镜像名：

kubeadm config images list --kubernetes-version=v1.15.1 #我的版本是1.15.1

2.下载所需镜像

步骤下载上述镜像，改名，删除原镜像

#kube-apiserver
sudo docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.15.1
sudo docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.15.1 k8s.gcr.io/kube-apiserver:v1.15.1
sudo docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.15.1

#kube-controller-manager
sudo docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.15.1
sudo docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.15.1 k8s.gcr.io/kube-controller-manager:v1.15.1
sudo docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.15.1

#kube-proxy
sudo docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.15.1
sudo docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.15.1 k8s.gcr.io/kube-proxy:v1.15.1
sudo docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.15.1

#kube-scheduler
sudo docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.15.1
sudo docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.15.1 k8s.gcr.io/kube-scheduler:v1.15.1
sudo docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.15.1

#pause
sudo docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
sudo docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1
sudo docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1

#etcd
sudo docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.10
sudo docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.10 k8s.gcr.io/etcd:3.3.10
sudo docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.3.10

#coredns
sudo docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.3.1
sudo docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.3.1 k8s.gcr.io/coredns:1.3.1
sudo docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.3.1

环境变量修改

添加环境变量并重启服务：

sudo gedit /etc/profile
export KUBECONFIG=/etc/kubernetes/admin.conf

systemctl daemon-reload
systemctl restart kubelet

此时，运行主节点初始化

sudo kubeadm init --kubernetes-version=1.15.1

会发现初始化成功，但是无法用kubectl get nodes查看节点，并出现以下错误。

The connection to the server localhost:8080 was refused - did you specify the right host or port?

这时还需要管理员配置文件：

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

再次查看发现错误消失，但是节点状态不对。

CNI 网络配置

查看kubelet的日志，我们会发现如下错误：

journalctl -xefu kubelet
ubelet.go:2169] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

这说明网络存在问题，通过安装cni网络插件可以解决。这里使用的网络插件为calico，插件的两个配置文件见后文。运行插件后，等一段时间并再次查看节点状态：

kubectl apply -f calico-rbac.yml
kubectl apply -f calico.yml
systemctl restart kubelet #重启kubelet服务

可以看到节点状态以正常，注意要保存kubeadm init产生的token命令，其他节点可以通过此命令加入集群：

calico网络插件yml文件

以下两份文件均转载自kubeadm快速部署kubernetes(1.15.0,HA)
calico-rbac.yml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: calico-node
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: calico-kube-controllers
  namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: calico-kube-controllers
rules:
  - apiGroups: [""]
    resources:
      - pods
      - nodes
      - namespaces
      - serviceaccounts
    verbs:
      - watch
      - list
  - apiGroups: ["networking.k8s.io"]
    resources:
      - networkpolicies
    verbs:
      - watch
      - list
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: calico-kube-controllers
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: calico-kube-controllers
subjects:
- kind: ServiceAccount
  name: calico-kube-controllers
  namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: calico-node
rules:
  - apiGroups: [""]
    resources:
      - pods
      - nodes
      - namespaces
    verbs:
      - get
  - apiGroups: [""]
    resources:
      - endpoints
      - services
    verbs:
      - watch
      - list
  - apiGroups: [""]
    resources:
      - nodes/status
    verbs:
      - patch
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: calico-node
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: calico-node
subjects:
- kind: ServiceAccount
  name: calico-node
  namespace: kube-system

calico.yml

---
# Source: calico/templates/calico-etcd-secrets.yaml
# The following contains k8s Secrets for use with a TLS enabled etcd cluster.
# For information on populating Secrets, see http://kubernetes.io/docs/user-guide/secrets/
apiVersion: v1
kind: Secret
type: Opaque
metadata:
  name: calico-etcd-secrets
  namespace: kube-system
data:
  # Populate the following with etcd TLS configuration if desired, but leave blank if
  # not using TLS for etcd.
  # The keys below should be uncommented and the values populated with the base64
  # encoded contents of each file that would be associated with the TLS data.
  # Example command for encoding a file contents: cat <file> | base64 -w 0
  # etcd-key: null
  # etcd-cert: null
  # etcd-ca: null
---
# Source: calico/templates/calico-config.yaml
# This ConfigMap is used to configure a self-hosted Calico installation.
kind: ConfigMap
apiVersion: v1
metadata:
  name: calico-config
  namespace: kube-system
data:
  # Configure this with the location of your etcd cluster.
  etcd_endpoints: "http://172.16.1.1:2379,http://172.16.1.2:2379,http://172.16.1.3:2379"
  # If you're using TLS enabled etcd uncomment the following.
  # You must also populate the Secret below with these files.
  etcd_ca: ""   # "/calico-secrets/etcd-ca"
  etcd_cert: "" # "/calico-secrets/etcd-cert"
  etcd_key: ""  # "/calico-secrets/etcd-key"
  # Typha is disabled.
  typha_service_name: "none"
  # Configure the backend to use.
  calico_backend: "bird"

  # Configure the MTU to use
  veth_mtu: "1440"

  # The CNI network configuration to install on each node.  The special
  # values in this config will be automatically populated.
  cni_network_config: |-
    {
      "name": "k8s-pod-network",
      "cniVersion": "0.3.0",
      "plugins": [
        {
          "type": "calico",
          "log_level": "info",
          "etcd_endpoints": "__ETCD_ENDPOINTS__",
          "etcd_key_file": "__ETCD_KEY_FILE__",
          "etcd_cert_file": "__ETCD_CERT_FILE__",
          "etcd_ca_cert_file": "__ETCD_CA_CERT_FILE__",
          "mtu": __CNI_MTU__,
          "ipam": {
              "type": "calico-ipam"
          },
          "policy": {
              "type": "k8s"
          },
          "kubernetes": {
              "kubeconfig": "__KUBECONFIG_FILEPATH__"
          }
        },
        {
          "type": "portmap",
          "snat": true,
          "capabilities": {"portMappings": true}
        }
      ]
    }
---
# Source: calico/templates/calico-node.yaml
# This manifest installs the calico-node container, as well
# as the CNI plugins and network config on
# each master and worker node in a Kubernetes cluster.
kind: DaemonSet
apiVersion: extensions/v1beta1
metadata:
  name: calico-node
  namespace: kube-system
  labels:
    k8s-app: calico-node
spec:
  selector:
    matchLabels:
      k8s-app: calico-node
  updateStrategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
  template:
    metadata:
      labels:
        k8s-app: calico-node
      annotations:
        # This, along with the CriticalAddonsOnly toleration below,
        # marks the pod as a critical add-on, ensuring it gets
        # priority scheduling and that its resources are reserved
        # if it ever gets evicted.
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      nodeSelector:
        beta.kubernetes.io/os: linux
      hostNetwork: true
      tolerations:
        # Make sure calico-node gets scheduled on all nodes.
        - effect: NoSchedule
          operator: Exists
        # Mark the pod as a critical add-on for rescheduling.
        - key: CriticalAddonsOnly
          operator: Exists
        - effect: NoExecute
          operator: Exists
      serviceAccountName: calico-node
      # Minimize downtime during a rolling upgrade or deletion; tell Kubernetes to do a "force
      # deletion": https://kubernetes.io/docs/concepts/workloads/pods/pod/#termination-of-pods.
      terminationGracePeriodSeconds: 0
      initContainers:
        # This container installs the CNI binaries
        # and CNI network config file on each node.
        - name: install-cni
          image: calico/cni:v3.7.2
          command: ["/install-cni.sh"]
          env:
            # Name of the CNI config file to create.
            - name: CNI_CONF_NAME
              value: "10-calico.conflist"
            # The CNI network config to install on each node.
            - name: CNI_NETWORK_CONFIG
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: cni_network_config
            # The location of the etcd cluster.
            - name: ETCD_ENDPOINTS
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_endpoints
            # CNI MTU Config variable
            - name: CNI_MTU
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: veth_mtu
            # Prevents the container from sleeping forever.
            - name: SLEEP
              value: "false"
          volumeMounts:
            - mountPath: /host/opt/cni/bin
              name: cni-bin-dir
            - mountPath: /host/etc/cni/net.d
              name: cni-net-dir
            - mountPath: /calico-secrets
              name: etcd-certs
      containers:
        # Runs calico-node container on each Kubernetes node.  This
        # container programs network policy and routes on each
        # host.
        - name: calico-node
          image: calico/node:v3.7.2
          env:
            # The location of the etcd cluster.
            - name: ETCD_ENDPOINTS
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_endpoints
            # Location of the CA certificate for etcd.
            - name: ETCD_CA_CERT_FILE
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_ca
            # Location of the client key for etcd.
            - name: ETCD_KEY_FILE
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_key
            # Location of the client certificate for etcd.
            - name: ETCD_CERT_FILE
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_cert
            # Set noderef for node controller.
            - name: CALICO_K8S_NODE_REF
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            # Choose the backend to use.
            - name: CALICO_NETWORKING_BACKEND
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: calico_backend
            # Cluster type to identify the deployment type
            - name: CLUSTER_TYPE
              value: "k8s,bgp"
            # Auto-detect the BGP IP address.
            - name: IP
              value: "autodetect"
            # Enable IPIP
            - name: CALICO_IPV4POOL_IPIP
              value: "Always"
            # Set MTU for tunnel device used if ipip is enabled
            - name: FELIX_IPINIPMTU
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: veth_mtu
            # The default IPv4 pool to create on startup if none exists. Pod IPs will be
            # chosen from this range. Changing this value after installation will have
            # no effect. This should fall within `--cluster-cidr`.
            - name: CALICO_IPV4POOL_CIDR
              value: "10.68.0.0/16"
            # Disable file logging so `kubectl logs` works.
            - name: CALICO_DISABLE_FILE_LOGGING
              value: "true"
            # Set Felix endpoint to host default action to ACCEPT.
            - name: FELIX_DEFAULTENDPOINTTOHOSTACTION
              value: "ACCEPT"
            # Disable IPv6 on Kubernetes.
            - name: FELIX_IPV6SUPPORT
              value: "false"
            # Set Felix logging to "info"
            - name: FELIX_LOGSEVERITYSCREEN
              value: "info"
            - name: FELIX_HEALTHENABLED
              value: "true"
          securityContext:
            privileged: true
          resources:
            requests:
              cpu: 250m
          livenessProbe:
            httpGet:
              path: /liveness
              port: 9099
              host: localhost
            periodSeconds: 10
            initialDelaySeconds: 10
            failureThreshold: 6
          readinessProbe:
            exec:
              command:
              - /bin/calico-node
              - -bird-ready
              - -felix-ready
            periodSeconds: 10
          volumeMounts:
            - mountPath: /lib/modules
              name: lib-modules
              readOnly: true
            - mountPath: /run/xtables.lock
              name: xtables-lock
              readOnly: false
            - mountPath: /var/run/calico
              name: var-run-calico
              readOnly: false
            - mountPath: /var/lib/calico
              name: var-lib-calico
              readOnly: false
            - mountPath: /calico-secrets
              name: etcd-certs
      volumes:
        # Used by calico-node.
        - name: lib-modules
          hostPath:
            path: /lib/modules
        - name: var-run-calico
          hostPath:
            path: /var/run/calico
        - name: var-lib-calico
          hostPath:
            path: /var/lib/calico
        - name: xtables-lock
          hostPath:
            path: /run/xtables.lock
            type: FileOrCreate
        # Used to install CNI.
        - name: cni-bin-dir
          hostPath:
            path: /opt/cni/bin
        - name: cni-net-dir
          hostPath:
            path: /etc/cni/net.d
        # Mount in the etcd TLS secrets with mode 400.
        # See https://kubernetes.io/docs/concepts/configuration/secret/
        - name: etcd-certs
          secret:
            secretName: calico-etcd-secrets
            defaultMode: 0400
---
# Source: calico/templates/calico-kube-controllers.yaml
# See https://github.com/projectcalico/kube-controllers
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: calico-kube-controllers
  namespace: kube-system
  labels:
    k8s-app: calico-kube-controllers
  annotations:
    scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
  # The controllers can only have a single active instance.
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      name: calico-kube-controllers
      namespace: kube-system
      labels:
        k8s-app: calico-kube-controllers
    spec:
      nodeSelector:
        beta.kubernetes.io/os: linux
      # The controllers must run in the host network namespace so that
      # it isn't governed by policy that would prevent it from working.
      hostNetwork: true
      tolerations:
        # Mark the pod as a critical add-on for rescheduling.
        - key: CriticalAddonsOnly
          operator: Exists
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
      serviceAccountName: calico-kube-controllers
      containers:
        - name: calico-kube-controllers
          image: calico/kube-controllers:v3.7.2
          env:
            # The location of the etcd cluster.
            - name: ETCD_ENDPOINTS
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_endpoints
            # Location of the CA certificate for etcd.
            - name: ETCD_CA_CERT_FILE
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_ca
            # Location of the client key for etcd.
            - name: ETCD_KEY_FILE
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_key
            # Location of the client certificate for etcd.
            - name: ETCD_CERT_FILE
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_cert
            # Choose which controllers to run.
            - name: ENABLED_CONTROLLERS
              value: policy,namespace,serviceaccount,workloadendpoint,node
          volumeMounts:
            # Mount in the etcd TLS secrets.
            - mountPath: /calico-secrets
              name: etcd-certs
          readinessProbe:
            exec:
              command:
              - /usr/bin/check-status
              - -r
      volumes:
        # Mount in the etcd TLS secrets with mode 400.
        # See https://kubernetes.io/docs/concepts/configuration/secret/
        - name: etcd-certs
          secret:
            secretName: calico-etcd-secrets
            defaultMode: 0400