kubeadm快速部署kubernetes(HA)

2017/11/10 docker Cloud

当前版本的kubeadm原生并不支持部署HA模式集群,但是实际上可以使用kubeadm部署后,再进行少量手动修改,即可实现HA模式的kubernetes集群。本次部署基于Ubuntu16.04,并使用最新的docker版本:17.06,kubernetes适用1.7.x版本,本文采用1.7.6。

1 环境准备

准备了六台机器作安装测试工作,机器信息如下:

IP Name Role OS
172.16.2.1 Master01 Controller,etcd Ubuntu16.04
172.16.2.2 Master02 Controller,etcd Ubuntu16.04
172.16.2.3 Master03 Controller,etcd Ubuntu16.04
172.16.2.11 Node01 Compute Ubuntu16.04
172.16.2.12 Node02 Compute Ubuntu16.04
172.16.2.13 Node03 Compute Ubuntu16.04
172.16.2.100 VIP VIP -

2 安装docker

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

apt-get update && apt-upgrade

apt-get install docker-ce=17.06.0~ce-0~ubuntu

3 安装etcd集群

使用了docker-compose安装,当然,如果觉得麻烦,也可以直接docker run。

Master01节点的ETCD的docker-compose.yml:

etcd:
  image: quay.io/coreos/etcd:v3.1.5
  command: etcd --name etcd-srv1 --data-dir=/var/etcd/calico-data --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://172.16.2.1:2379,http://172.16.2.1:2380 --initial-advertise-peer-urls http://172.16.2.1:2380 --listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd-srv1=http://172.16.2.1:2380,etcd-srv2=http://172.16.2.2:2380,etcd-srv3=http://172.16.2.3:2380" -initial-cluster-state new
  net: "bridge"
  ports:
  - "2379:2379"
  - "2380:2380"
  restart: always
  stdin_open: true
  tty: true
  volumes:
  - /store/etcd:/var/etcd

Master02节点的ETCD的docker-compose.yml:

etcd:
  image: quay.io/coreos/etcd:v3.1.5
  command: etcd --name etcd-srv2 --data-dir=/var/etcd/calico-data --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://172.16.2.2:2379,http://172.16.2.2:2380 --initial-advertise-peer-urls http://172.16.2.2:2380 --listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd-srv1=http://172.16.2.1:2380,etcd-srv2=http://172.16.2.2:2380,etcd-srv3=http://172.16.2.3:2380" -initial-cluster-state new
  net: "bridge"
  ports:
  - "2379:2379"
  - "2380:2380"
  restart: always
  stdin_open: true
  tty: true
  volumes:
  - /store/etcd:/var/etcd

Master03节点的ETCD的docker-compose.yml:

etcd:
  image: quay.io/coreos/etcd:v3.1.5
  command: etcd --name etcd-srv3 --data-dir=/var/etcd/calico-data --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://172.16.2.3:2379,http://172.16.2.3:2380 --initial-advertise-peer-urls http://172.16.2.3:2380 --listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd-srv1=http://172.16.2.1:2380,etcd-srv2=http://172.16.2.2:2380,etcd-srv3=http://172.16.2.3:2380" -initial-cluster-state new
  net: "bridge"
  ports:
  - "2379:2379"
  - "2380:2380"
  restart: always
  stdin_open: true
  tty: true
  volumes:
  - /store/etcd:/var/etcd

创建好docker-compose.yml文件后,使用命令docker-compose up -d部署。

关于docker-compose的使用,可以参考:docker-compose安装文档

3 安装k8s工具包

三种方式:博主提供、官方源安装和release工程编译,apt-get方式因为不能直接使用google提供的源,非官方源中提供的版本比较老,如果要使用新版本,可以尝试release工程编译的方式或者用博主提供的包下载。

博主提供

一些比较懒得同学:-D,可以直接从博主提供的位置下载RPM工具包安装,下载地址

#安装kubelet的依赖包
apt-get install -y socat ebtables
dpkg -i kubelet_1.7.6-00_amd64.deb kubeadm_1.7.6-00_amd64.deb kubernetes-cni_0.5.1-00_amd64.deb kubectl_1.7.6-00_amd64.deb

官方源安装

跨越GFW方式不细说,你懂的。

apt-get update && apt-get install -y apt-transport-https

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF

apt-get update

apt-get install -y kubelet kubeadm kubernetes-cni kubectl

默认安装最新的stable版本,可以根据需要指定安装版本apt-get install -y kubeadm=1.7.6-00,版本信息可以使用命令查看:apt-cache madison kubeadm

relese编译

git clone https://github.com/kubernetes/release.git

docker build --tag=debian-packager debian
docker run --volume="$(pwd)/debian:/src" debian-packager

编译完成后生成deb包到:debian/bin,进入到该目录后安装deb包。

4 镜像准备

4.1 下载docker镜像

kubeadm方式安装kubernetes集群需要的镜像在docker官方镜像中并未提供,只能去google的官方镜像库:gcr.io 中下载,GFW咋办?这里针对k8s-1.7.6在DockerHub上做了跳板镜像,各位可以直接下载,dashboard的版本并未紧跟kubelet主线版本,用哪个版本都可以,本文使用kubernetes-dashboard-amd64:v1.7.0。

kubernetes-1.7.6所需要的镜像:

  • etcd-amd64:3.0.17
  • pause-amd64:3.0
  • kube-proxy-amd64:v1.7.6
  • kube-scheduler-amd64:v1.7.6
  • kube-controller-manager-amd64:v1.7.6
  • kube-apiserver-amd64:v1.7.6
  • kubernetes-dashboard-amd64:v1.7.0
  • k8s-dns-sidecar-amd64:1.14.4
  • k8s-dns-kube-dns-amd64:1.14.4
  • k8s-dns-dnsmasq-nanny-amd64:1.14.4

偷下懒吧,直接执行以下脚本,提前下载好镜像,后边的动作就快了:

#!/bin/bash
images=(kube-proxy-amd64:v1.7.6 kube-scheduler-amd64:v1.7.6 kube-controller-manager-amd64:v1.7.6 kube-apiserver-amd64:v1.7.6 etcd-amd64:3.0.17 pause-amd64:3.0 kubernetes-dashboard-amd64:v1.6.1 k8s-dns-sidecar-amd64:1.14.4 k8s-dns-kube-dns-amd64:1.14.4 k8s-dns-dnsmasq-nanny-amd64:1.14.4)
for imageName in ${images[@]} ; do
  docker pull cloudnil/$imageName
done

4.2 KUBE_REPO_PREFIX配置

通过KUBE_REPO_PREFIX配置官方镜像包的仓库位置,才可以直接使用从DockerHub上下载的镜像,请使用以下命令增加配置:1.KUBE_REPO_PREFIX环境变量 2.KUBELET_EXTRA_ARGS参数。

sed -i '/mesg n/i\export KUBE_REPO_PREFIX=cloudnil' ~/.profile
source ~/.profile

cat > /etc/systemd/system/kubelet.service.d/20-extra-args.conf <<EOF
[Service]
Environment="KUBELET_EXTRA_ARGS=--pod-infra-container-image=cloudnil/pause-amd64:3.0"
EOF

systemctl daemon-reload
systemctl restart kubelet

5 安装master节点

由于kubeadm和kubelet安装过程中会生成/etc/kubernetes目录,而kubeadm init会先检测该目录是否存在,所以我们先使用kubeadm初始化环境。

kubeadm reset
kubeadm init --api-advertise-addresses=172.16.2.1 --use-kubernetes-version v1.7.6

如果使用外部etcd集群,以前的kubeadm版本的--external-etcd-endpoints参数已经没有了,所以要使用–config参数外挂配置文件kubeadm-config.yml:

apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
# networking:
#   podSubnet: 10.244.0.0/16
apiServerCertSANs:
- master01
- master02
- master03
- 172.16.2.1
- 172.16.2.2
- 172.16.2.3
- 172.16.2.100
etcd:
  endpoints:
  - http://172.16.2.1:2379
  - http://172.16.2.2:2379
  - http://172.16.2.3:2379
token: 67e411.zc3617bb21ad7ee3
kubernetesVersion: v1.7.6

PS:token是使用指令kubeadm token generate生成的。

初始化指令:

kubeadm init --config kubeadm-config.yml

说明:如果打算使用flannel网络,请去掉networking注释。如果有多网卡的,请根据实际情况配置--api-advertise-addresses=<ip-address>,单网卡情况可以省略。

安装过程大概2-3分钟,输出结果如下:

[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[init] Using Kubernetes version: v1.7.6
[tokens] Generated token: "67e411.zc3617bb21ad7ee3"
[certificates] Generated Certificate Authority key and certificate.
[certificates] Generated API Server key and certificate
[certificates] Generated Service Account signing keys
[certificates] Created keys and certificates in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/scheduler.conf"
[apiclient] Created API client, waiting for the control plane to become ready
[apiclient] All control plane components are healthy after 21.317580 seconds
[apiclient] Waiting for at least one node to register and become ready
[apiclient] First node is ready after 6.556101 seconds
[apiclient] Creating a test deployment
[apiclient] Test deployment succeeded
[addons] Created essential addon: kube-proxy

Your Kubernetes master has initialized successfully!

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

You can now join any number of machines by running the following on each node:

kubeadm join --token=67e411.zc3617bb21ad7ee3 172.16.2.1

修改/etc/kubernetes/manifests/kube-apiserver.yaml中的admission-control策略:

root@master01:/etc/kubernetes/manifests# vi kube-apiserver.yaml

#- --admission-control=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,ResourceQuota
- --admission-control=NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,ResourceQuota,DefaultTolerationSeconds

复制/etc/kubernetes到Master02和Master03

scp -r /etc/kubernetes 172.16.2.2:/etc/kubernetes
scp -r /etc/kubernetes 172.16.2.3:/etc/kubernetes

修改/etc/kubernetes/etc/kubernetes/manifests以下文件:

#Master02
root@master02:/etc/kubernetes# sed -i 's/172.16.2.1:6443/172.16.2.2:6443/g' `grep 172.16.2.1:6443 . -rl`
root@master02:/etc/kubernetes# sed -i 's/--advertise-address=172.16.2.1/--advertise-address=172.16.2.2/g' manifests/kube-apiserver.yaml

#Master03
root@master03:/etc/kubernetes# sed -i 's/172.16.2.1:6443/172.16.2.3:6443/g' `grep 172.16.2.1:6443 . -rl`
root@master03:/etc/kubernetes# sed -i 's/--advertise-address=172.16.2.1/--advertise-address=172.16.2.3/g' manifests/kube-apiserver.yaml

Master02和Master03节点重启kubelet服务。

systemctl restart kubelet

6 安装keepalived

Master01、Master02、Master03上分别安装keepalived,配置VIP为172.16.2.100

详细过程略过,网络上很多教程,请各位自行查阅。

7 安装Node节点

Master节点安装好了Node节点就简单了。

kubeadm reset
kubeadm join --token=67e411.zc3617bb21ad7ee3 172.16.2.100

输出结果如下:

[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] Starting the kubelet service
[tokens] Validating provided token
[discovery] Created cluster info discovery client, requesting info from "http://172.16.2.100:9898/cluster-info/v1/?token-id=f11877"
[discovery] Cluster info object received, verifying signature using given token
[discovery] Cluster info signature and contents are valid, will use API endpoints [https://172.16.2.100:6443]
[bootstrap] Trying to connect to endpoint https://172.16.2.100:6443
[bootstrap] Detected server version: v1.7.6
[bootstrap] Successfully established connection with endpoint "https://172.16.2.100:6443"
[csr] Created API client to obtain unique certificate for this node, generating keys and certificate signing request
[csr] Received signed certificate from the API server:
Issuer: CN=kubernetes | Subject: CN=system:node:yournode | CA: false
Not before: 2017-06-28 19:44:00 +0000 UTC Not After: 2018-06-28 19:44:00 +0000 UTC
[csr] Generating kubelet configuration
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"

Node join complete:
* Certificate signing request sent to master and response
  received.
* Kubelet informed of new secure connection details.

Run 'kubectl get nodes' on the master to see this machine join.

安装完成后可以查看下状态,未安装网络组件,所以全部都是NotReady状态:

NAME       STATUS        AGE      VERSION
master01   NotReady      1d       v1.7.6
master02   NotReady      1d       v1.7.6
master03   NotReady      1d       v1.7.6
node01     NotReady      1d       v1.7.6
node02     NotReady      1d       v1.7.6
node03     NotReady      1d       v1.7.6

8 安装Calico网络

网络组件选择很多,可以根据自己的需要选择calico、weave、flannel,calico性能最好,flannel的vxlan也不错,默认的UDP性能较差,weave的性能比较差,测试环境用下可以,生产环境不建议使用。Addons中有配置好的yaml,所以本文中尝试calico网络,。

kubectl apply -f https://docs.projectcalico.org/v2.5/getting-started/kubernetes/installation/hosted/kubeadm/1.6/calico.yaml

如果使用了外部etcd,去掉etcd相关配置内容,并修改etcd_endpoints: [ETCD_ENDPOINTS]

# Calico Version v2.5.1
# https://docs.projectcalico.org/v2.5/releases#v2.5.1
# This manifest includes the following component versions:
#   calico/node:v2.5.1
#   calico/cni:v1.10.0
#   calico/kube-policy-controller:v0.7.0

# This ConfigMap is used to configure a self-hosted Calico installation.
kind: ConfigMap
apiVersion: v1
metadata:
  name: calico-config
  namespace: kube-system
data:
  # The location of your etcd cluster.  This uses the Service clusterIP defined below.
  etcd_endpoints: "http://172.16.2.1:2379,http://172.16.2.2:2379,http://172.16.2.3:2379"

  # Configure the Calico backend to use.
  calico_backend: "bird"

  # The CNI network configuration to install on each node.
  cni_network_config: |-
    {
        "name": "k8s-pod-network",
        "cniVersion": "0.1.0",
        "type": "calico",
        "etcd_endpoints": "__ETCD_ENDPOINTS__",
        "log_level": "info",
        "mtu": 1500,
        "ipam": {
            "type": "calico-ipam"
        },
        "policy": {
            "type": "k8s",
             "k8s_api_root": "https://__KUBERNETES_SERVICE_HOST__:__KUBERNETES_SERVICE_PORT__",
             "k8s_auth_token": "__SERVICEACCOUNT_TOKEN__"
        },
        "kubernetes": {
            "kubeconfig": "/etc/cni/net.d/__KUBECONFIG_FILENAME__"
        }
    }

---

# This manifest installs the calico/node container, as well
# as the Calico 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
  template:
    metadata:
      labels:
        k8s-app: calico-node
      annotations:
        # Mark this pod as a critical add-on; when enabled, the critical add-on scheduler
        # reserves resources for critical add-on pods so that they can be rescheduled after
        # a failure.  This annotation works in tandem with the toleration below.
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      hostNetwork: true
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
      # Allow this pod to be rescheduled while the node is in "critical add-ons only" mode.
      # This, along with the annotation above marks this pod as a critical add-on.
      - key: CriticalAddonsOnly
        operator: Exists
      serviceAccountName: calico-cni-plugin
      containers:
        # Runs calico/node container on each Kubernetes node.  This
        # container programs network policy and routes on each
        # host.
        - name: calico-node
          image: quay.io/calico/node:v2.5.1
          env:
            # The location of the Calico etcd cluster.
            - name: ETCD_ENDPOINTS
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_endpoints
            # Enable BGP.  Disable to enforce policy only.
            - name: CALICO_NETWORKING_BACKEND
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: calico_backend
            # Cluster type to identify the deployment type
            - name: CLUSTER_TYPE
              value: "kubeadm,bgp"
            # 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"
            # Configure the IP Pool from which Pod IPs will be chosen.
            - name: CALICO_IPV4POOL_CIDR
              value: "10.68.0.0/16"
            - name: CALICO_IPV4POOL_IPIP
              value: "always"
            # Disable IPv6 on Kubernetes.
            - name: FELIX_IPV6SUPPORT
              value: "false"
            # Set MTU for tunnel device used if ipip is enabled
            - name: FELIX_IPINIPMTU
              value: "1440"
            # Set Felix logging to "info"
            - name: FELIX_LOGSEVERITYSCREEN
              value: "info"
            # Auto-detect the BGP IP address.
            - name: IP
              value: ""
            - name: FELIX_HEALTHENABLED
              value: "true"
          securityContext:
            privileged: true
          resources:
            requests:
              cpu: 250m
          livenessProbe:
            httpGet:
              path: /liveness
              port: 9099
            periodSeconds: 10
            initialDelaySeconds: 10
            failureThreshold: 6
          readinessProbe:
            httpGet:
              path: /readiness
              port: 9099
            periodSeconds: 10
          volumeMounts:
            - mountPath: /lib/modules
              name: lib-modules
              readOnly: true
            - mountPath: /var/run/calico
              name: var-run-calico
              readOnly: false
        # This container installs the Calico CNI binaries
        # and CNI network config file on each node.
        - name: install-cni
          image: quay.io/calico/cni:v1.10.0
          command: ["/install-cni.sh"]
          env:
            # The location of the Calico etcd cluster.
            - name: ETCD_ENDPOINTS
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_endpoints
            # The CNI network config to install on each node.
            - name: CNI_NETWORK_CONFIG
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: cni_network_config
          volumeMounts:
            - mountPath: /host/opt/cni/bin
              name: cni-bin-dir
            - mountPath: /host/etc/cni/net.d
              name: cni-net-dir
      volumes:
        # Used by calico/node.
        - name: lib-modules
          hostPath:
            path: /lib/modules
        - name: var-run-calico
          hostPath:
            path: /var/run/calico
        # Used to install CNI.
        - name: cni-bin-dir
          hostPath:
            path: /opt/cni/bin
        - name: cni-net-dir
          hostPath:
            path: /etc/cni/net.d

---

# This manifest deploys the Calico policy controller on Kubernetes.
# See https://github.com/projectcalico/k8s-policy
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: calico-policy-controller
  namespace: kube-system
  labels:
    k8s-app: calico-policy
spec:
  # The policy controller can only have a single active instance.
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      name: calico-policy-controller
      namespace: kube-system
      labels:
        k8s-app: calico-policy-controller
      annotations:
        # Mark this pod as a critical add-on; when enabled, the critical add-on scheduler
        # reserves resources for critical add-on pods so that they can be rescheduled after
        # a failure.  This annotation works in tandem with the toleration below.
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      # The policy controller must run in the host network namespace so that
      # it isn't governed by policy that would prevent it from working.
      hostNetwork: true
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
      # Allow this pod to be rescheduled while the node is in "critical add-ons only" mode.
      # This, along with the annotation above marks this pod as a critical add-on.
      - key: CriticalAddonsOnly
        operator: Exists
      serviceAccountName: calico-policy-controller
      containers:
        - name: calico-policy-controller
          image: quay.io/calico/kube-policy-controller:v0.7.0
          env:
            # The location of the Calico etcd cluster.
            - name: ETCD_ENDPOINTS
              valueFrom:
                configMapKeyRef:
                  name: calico-config
                  key: etcd_endpoints
            # The location of the Kubernetes API.  Use the default Kubernetes
            # service for API access.
            - name: K8S_API
              value: "https://kubernetes.default:443"
            # Since we're running in the host namespace and might not have KubeDNS
            # access, configure the container's /etc/hosts to resolve
            # kubernetes.default to the correct service clusterIP.
            - name: CONFIGURE_ETC_HOSTS
              value: "true"
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: calico-cni-plugin
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: calico-cni-plugin
subjects:
- kind: ServiceAccount
  name: calico-cni-plugin
  namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: calico-cni-plugin
  namespace: kube-system
rules:
  - apiGroups: [""]
    resources:
      - pods
      - nodes
    verbs:
      - get
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: calico-cni-plugin
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: calico-policy-controller
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: calico-policy-controller
subjects:
- kind: ServiceAccount
  name: calico-policy-controller
  namespace: kube-system
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: calico-policy-controller
  namespace: kube-system
rules:
  - apiGroups:
    - ""
    - extensions
    resources:
      - pods
      - namespaces
      - networkpolicies
    verbs:
      - watch
      - list
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: calico-policy-controller
  namespace: kube-system

检查各节点组件运行状态:

NAME                                        READY     STATUS     RESTARTS   AGE
calico-node-0cjx5                           2/2       Running    0          1d
calico-node-1vj9s                           2/2       Running    0          1d
calico-node-222v0                           2/2       Running    0          1d
calico-node-7nqj7                           2/2       Running    0          1d
calico-node-7tvh9                           2/2       Running    0          1d
calico-node-86313                           2/2       Running    2          1d
calico-policy-controller-3691403067-43wm6   1/1       Running    3          1d
kube-apiserver-master01                     1/1       Running    3          1d
kube-apiserver-master02                     1/1       Running    1          1d
kube-apiserver-master03                     1/1       Running    1          1d
kube-controller-manager-master01            1/1       Running    4          1d
kube-controller-manager-master02            1/1       Running    2          1d
kube-controller-manager-master03            1/1       Running    2          1d
kube-dns-4099109879-3hqtq                   3/3       Running    0          1d
kube-proxy-43j51                            1/1       Running    1          1d
kube-proxy-4z8mx                            1/1       Running    0          1d
kube-proxy-8w1xh                            1/1       Running    0          1d
kube-proxy-g2hv8                            1/1       Running    1          1d
kube-proxy-hzkmc                            1/1       Running    1          1d
kube-proxy-l91xr                            1/1       Running    0          1d
kube-scheduler-master01                     1/1       Running    4          1d
kube-scheduler-master02                     1/1       Running    2          1d
kube-scheduler-master03                     1/1       Running    2          1d

说明:kube-dns需要等calico配置完成后才是running状态。

8 DNS集群部署

删除原单点kube-dns

kubectl delete deploy kube-dns -n kube-system

部署多实例的kube-dns集群,参考配置kube-dns.yml:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  labels:
    k8s-app: kube-dns
  name: kube-dns
  namespace: kube-system
spec:
  replicas: 3
  selector:
    matchLabels:
      k8s-app: kube-dns
  strategy:
    rollingUpdate:
      maxSurge: 10%
      maxUnavailable: 0
    type: RollingUpdate
  template:
    metadata:
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ""
      creationTimestamp: null
      labels:
        k8s-app: kube-dns
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: beta.kubernetes.io/arch
                operator: In
                values:
                - amd64
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: k8s-app
                    operator: In
                    values:
                    - kube-dns
              topologyKey: "kubernetes.io/hostname"
      containers:
      - args:
        - --domain=cluster.local.
        - --dns-port=10053
        - --config-dir=/kube-dns-config
        - --v=2
        env:
        - name: PROMETHEUS_PORT
          value: "10055"
        image: cloudnil/k8s-dns-kube-dns-amd64:1.14.4
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 5
          httpGet:
            path: /healthcheck/kubedns
            port: 10054
            scheme: HTTP
          initialDelaySeconds: 60
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 5
        name: kubedns
        ports:
        - containerPort: 10053
          name: dns-local
          protocol: UDP
        - containerPort: 10053
          name: dns-tcp-local
          protocol: TCP
        - containerPort: 10055
          name: metrics
          protocol: TCP
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /readiness
            port: 8081
            scheme: HTTP
          initialDelaySeconds: 3
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 5
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /kube-dns-config
          name: kube-dns-config
      - args:
        - -v=2
        - -logtostderr
        - -configDir=/etc/k8s/dns/dnsmasq-nanny
        - -restartDnsmasq=true
        - --
        - -k
        - --cache-size=1000
        - --log-facility=-
        - --server=/cluster.local/127.0.0.1#10053
        - --server=/in-addr.arpa/127.0.0.1#10053
        - --server=/ip6.arpa/127.0.0.1#10053
        image: cloudnil/k8s-dns-dnsmasq-nanny-amd64:1.14.4
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 5
          httpGet:
            path: /healthcheck/dnsmasq
            port: 10054
            scheme: HTTP
          initialDelaySeconds: 60
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 5
        name: dnsmasq
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        resources:
          requests:
            cpu: 150m
            memory: 20Mi
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /etc/k8s/dns/dnsmasq-nanny
          name: kube-dns-config
      - args:
        - --v=2
        - --logtostderr
        - --probe=kubedns,127.0.0.1:10053,kubernetes.default.svc.cluster.local,5,A
        - --probe=dnsmasq,127.0.0.1:53,kubernetes.default.svc.cluster.local,5,A
        image: cloudnil/k8s-dns-sidecar-amd64:1.14.4
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 5
          httpGet:
            path: /metrics
            port: 10054
            scheme: HTTP
          initialDelaySeconds: 60
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 5
        name: sidecar
        ports:
        - containerPort: 10054
          name: metrics
          protocol: TCP
        resources:
          requests:
            cpu: 10m
            memory: 20Mi
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: Default
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      serviceAccount: kube-dns
      serviceAccountName: kube-dns
      terminationGracePeriodSeconds: 30
      tolerations:
      - effect: NoSchedule
        key: node-role.kubernetes.io/master
      - key: CriticalAddonsOnly
        operator: Exists
      volumes:
      - configMap:
          defaultMode: 420
          name: kube-dns
          optional: true
        name: kube-dns-config

9 部署Dashboard

下载kubernetes-dashboard.yaml

curl -O https://rawgit.com/kubernetes/dashboard/master/src/deploy/kubernetes-dashboard.yaml

修改配置内容,部署到default的namespace,增加ingress配置,后边配置了nginx-ingress后就可以直接绑定域名访问了。

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard
  labels:
    k8s-app: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: default
---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: default
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
      - name: kubernetes-dashboard
        image: cloudnil/kubernetes-dashboard-amd64:v1.7.0
        ports:
        - containerPort: 9090
          protocol: TCP
        args:
        livenessProbe:
          httpGet:
            path: /
            port: 9090
          initialDelaySeconds: 30
          timeoutSeconds: 30
      serviceAccountName: kubernetes-dashboard
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
---
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: default
spec:
  ports:
  - port: 80
    targetPort: 9090
  selector:
    k8s-app: kubernetes-dashboard
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: dashboard-ingress
  namespace: default
spec:
  rules:
  - host: dashboard.cloudnil.com
    http:
      paths:
      - path: /
        backend:
          serviceName: kubernetes-dashboard
          servicePort: 80

10 Dashboard服务暴露到公网

kubernetes中的Service暴露到外部有三种方式,分别是:

  • LoadBlancer Service
  • NodePort Service
  • Ingress

LoadBlancer Service是kubernetes深度结合云平台的一个组件;当使用LoadBlancer Service暴露服务时,实际上是通过向底层云平台申请创建一个负载均衡器来向外暴露服务;目前LoadBlancer Service支持的云平台已经相对完善,比如国外的GCE、DigitalOcean,国内的 阿里云,私有云 Openstack 等等,由于LoadBlancer Service深度结合了云平台,所以只能在一些云平台上来使用。

NodePort Service顾名思义,实质上就是通过在集群的每个node上暴露一个端口,然后将这个端口映射到某个具体的service来实现的,虽然每个node的端口有很多(0~65535),但是由于安全性和易用性(服务多了就乱了,还有端口冲突问题)实际使用可能并不多。

Ingress可以实现使用nginx等开源的反向代理负载均衡器实现对外暴露服务,可以理解Ingress就是用于配置域名转发的一个东西,在nginx中就类似upstream,它与ingress-controller结合使用,通过ingress-controller监控到pod及service的变化,动态地将ingress中的转发信息写到诸如nginx、apache、haproxy等组件中实现方向代理和负载均衡。

10.1 部署Nginx-ingress-controller

Nginx-ingress-controller是kubernetes官方提供的集成了Ingress-controller和Nginx的一个docker镜像。

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: default-http-backend
  labels:
    k8s-app: default-http-backend
  namespace: default
spec:
  replicas: 1
  template:
    metadata:
      labels:
        k8s-app: default-http-backend
    spec:
      terminationGracePeriodSeconds: 60
      containers:
      - name: default-http-backend
        image: cloudnil/defaultbackend:1.0
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 30
          timeoutSeconds: 5
        ports:
        - containerPort: 8080
        resources:
          limits:
            cpu: 10m
            memory: 20Mi
          requests:
            cpu: 10m
            memory: 20Mi
---
apiVersion: v1
kind: Service
metadata:
  name: default-http-backend
  labels:
    k8s-app: default-http-backend
  namespace: default
spec:
  ports:
  - port: 80
    targetPort: 8080
  selector:
    k8s-app: default-http-backend
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: nginx-ingress-controller
  labels:
    k8s-app: nginx-ingress-controller
  namespace: default
spec:
  replicas: 1
  template:
    metadata:
      labels:
        k8s-app: nginx-ingress-controller
    spec:
      hostNetwork: true
      nodeName: master
      terminationGracePeriodSeconds: 60
      serviceAccountName: nginx-ingress-controller
      containers:
      - image: cloudnil/nginx-ingress-controller:0.9.0-beta.13
        name: nginx-ingress-controller
        readinessProbe:
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
        livenessProbe:
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
          initialDelaySeconds: 10
          timeoutSeconds: 1
        ports:
        - containerPort: 80
          hostPort: 80
        - containerPort: 443
          hostPort: 443
        env:
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: POD_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
        args:
        - /nginx-ingress-controller
        - --default-backend-service=$(POD_NAMESPACE)/default-http-backend
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nginx-ingress-controller
  namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: view-services-cluster
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: nginx-ingress-controller
  namespace: default

部署完Nginx-ingress-controller后,解析域名dashboard.cloudnil.com到node02的外网IP,就可以使用dashboard.cloudnil.com访问dashboard。

版权声明:允许转载,请注明原文出处:http://cloudnil.com/2017/11/10/Deploy-kubernetes-HA-with-kubeadm/。

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