Kubernetes集群指定组件版本安装脚本

 未分类  No Responses »
5 月 062020
  
#!/bin/bash
#

# 禁用SELINUX设置
setenforce 0;
sed -i 's/^SELINUX=enforcing$/SELINUX=disabled/' /etc/selinux/config;
# 加载内核模块及修改内核参数
cat > /etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF
modprobe overlay;
modprobe br_netfilter;
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
sysctl --system;
# 准备容器运行环境
yum makecache;
yum install -y yum-utils;
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo;
yum install -y docker-ce docker-ce-cli containerd.io;
containerd config default > /etc/containerd/config.toml;
#
mkdir /etc/docker;
cat <<EOF > /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}
EOF
#
systemctl daemon-reload;
systemctl enable docker;
systemctl restart docker;
# 准备K8S运行环境（指定组件版本）
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
#
yum install -y kubectl-1.16.9 kubelet-1.16.9 kubeadm-1.16.9;
systemctl enable kubelet;

Kubernetes 1.16.9 当前支持的经验证的Docker CE版本为18.09

[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.8. Latest validated version: 18.09

查看Docker CE YUM仓库当前可用版本（18.09.9）

[root@k8s-01 ~]# yum list docker-ce --showduplicates | sort -r
 * updates: mirrors.sonic.net
Loading mirror speeds from cached hostfile
Loaded plugins: fastestmirror
Installed Packages
 * extras: mirror.keystealth.org
docker-ce.x86_64            3:19.03.8-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.8-3.el7                    @docker-ce-stable
docker-ce.x86_64            3:19.03.7-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.6-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.5-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.4-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.3-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.2-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.1-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:19.03.0-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.9-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.8-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.7-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.6-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.5-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.4-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.3-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.2-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.1-3.el7                    docker-ce-stable 
docker-ce.x86_64            3:18.09.0-3.el7                    docker-ce-stable 
docker-ce.x86_64            18.06.3.ce-3.el7                   docker-ce-stable 
docker-ce.x86_64            18.06.2.ce-3.el7                   docker-ce-stable 
docker-ce.x86_64            18.06.1.ce-3.el7                   docker-ce-stable 
docker-ce.x86_64            18.06.0.ce-3.el7                   docker-ce-stable 
docker-ce.x86_64            18.03.1.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            18.03.0.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.12.1.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.12.0.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.09.1.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.09.0.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.06.2.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.06.1.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.06.0.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.03.3.ce-1.el7                   docker-ce-stable 
docker-ce.x86_64            17.03.2.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.03.1.ce-1.el7.centos            docker-ce-stable 
docker-ce.x86_64            17.03.0.ce-1.el7.centos            docker-ce-stable 
 * base: sjc.edge.kernel.org
Available Packages
[root@k8s-01 ~]#

Kuberntes集群中pod中容器服务的访问

 云计算, 容器化  No Responses »
5 月 062020
 

Kubernetes集群中的Service从逻辑上代表了一组Pod，并通过label建立与pod的关联

准备Deployment配置文件

[root@k8s-01 ~]# vi httpd-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpd
spec:
  replicas: 3
  selector:
    matchLabels:
      run: httpd
  template:
    metadata:
      labels:
        run: httpd
    spec:
      containers:
      - name: httpd
        image: httpd:2.4.41
        ports:
        - containerPort: 80
[root@k8s-01 ~]# kubectl apply -f httpd-deployment.yaml 
deployment.apps/httpd created
[root@k8s-01 ~]#

获取集群pod列表详情

[root@k8s-01 ~]# kubectl get pods -o wide
NAME                     READY   STATUS    RESTARTS   AGE     IP           NODE     NOMINATED NODE   READINESS GATES
httpd-5bb8cdb99c-g5m95   1/1     Running   0          4m29s   10.244.2.3   k8s-03   <none>           <none>
httpd-5bb8cdb99c-hzjqd   1/1     Running   0          4m29s   10.244.1.3   k8s-02   <none>           <none>
httpd-5bb8cdb99c-s4q25   1/1     Running   0          4m29s   10.244.1.4   k8s-02   <none>           <none>
[root@k8s-01 ~]#

使用CURL模拟浏览器请求pod的IP地址（Pod的IP地址只能被集群中的容器和节点访问到）

[root@k8s-01 ~]# curl 10.244.2.3
<html><body><h1>It works!</h1></body></html>
[root@k8s-01 ~]# curl 10.244.1.3
<html><body><h1>It works!</h1></body></html>
[root@k8s-01 ~]# curl 10.244.1.4
<html><body><h1>It works!</h1></body></html>
[root@k8s-01 ~]#

[root@k8s-02 ~]# curl 10.244.2.3
<html><body><h1>It works!</h1></body></html>
[root@k8s-02 ~]# curl 10.244.1.3
<html><body><h1>It works!</h1></body></html>
[root@k8s-02 ~]# curl 10.244.1.4
<html><body><h1>It works!</h1></body></html>
[root@k8s-02 ~]#

[root@k8s-03 ~]# curl 10.244.2.3
<html><body><h1>It works!</h1></body></html>
[root@k8s-03 ~]# curl 10.244.1.3
<html><body><h1>It works!</h1></body></html>
[root@k8s-03 ~]# curl 10.244.1.4
<html><body><h1>It works!</h1></body></html>
[root@k8s-03 ~]#

对Pod IP进行PING测试

[root@k8s-01 ~]# ping -c 2 10.244.2.3
PING 10.244.2.3 (10.244.2.3) 56(84) bytes of data.
64 bytes from 10.244.2.3: icmp_seq=1 ttl=63 time=2.03 ms
64 bytes from 10.244.2.3: icmp_seq=2 ttl=63 time=0.660 ms

--- 10.244.2.3 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.660/1.348/2.036/0.688 ms
[root@k8s-01 ~]# ping -c 2 10.244.1.3
PING 10.244.1.3 (10.244.1.3) 56(84) bytes of data.
64 bytes from 10.244.1.3: icmp_seq=1 ttl=63 time=1.58 ms
64 bytes from 10.244.1.3: icmp_seq=2 ttl=63 time=0.641 ms

--- 10.244.1.3 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.641/1.115/1.589/0.474 ms
[root@k8s-01 ~]# ping -c 2 10.244.1.4
PING 10.244.1.4 (10.244.1.4) 56(84) bytes of data.
64 bytes from 10.244.1.4: icmp_seq=1 ttl=63 time=0.658 ms
64 bytes from 10.244.1.4: icmp_seq=2 ttl=63 time=0.483 ms

--- 10.244.1.4 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.483/0.570/0.658/0.090 ms
[root@k8s-01 ~]#

创建服务Service配置文件

[root@k8s-01 ~]# vi httpd-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: httpd-service
spec:
  selector:
    run: httpd
  ports:
  - protocol: TCP
    port: 8080
    targetPort: 80
[root@k8s-01 ~]# kubectl apply -f httpd-service.yaml
service/httpd-service created
[root@k8s-01 ~]#

获取集群Service列表详情

[root@k8s-01 ~]# kubectl get services -o wide
NAME            TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE    SELECTOR
httpd-service   ClusterIP   10.109.145.140   <none>        8080/TCP   4m9s   run=httpd
kubernetes      ClusterIP   10.96.0.1        <none>        443/TCP    10m    <none>
[root@k8s-01 ~]#

尝试ping集群IP地址（默认无法ping通）

[root@k8s-01 ~]# ping 10.109.145.140
PING 10.109.145.140 (10.109.145.140) 56(84) bytes of data.
^C
--- 10.109.145.140 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms

[root@k8s-01 ~]#

使用Service获得的集群IP访问具有run=httpd标签的后端Pod及容器

[root@k8s-01 ~]# curl 10.109.145.140:8080
<html><body><h1>It works!</h1></body></html>
[root@k8s-01 ~]# curl 10.109.145.140:8080
<html><body><h1>It works!</h1></body></html>
[root@k8s-01 ~]# curl 10.109.145.140:8080
<html><body><h1>It works!</h1></body></html>
[root@k8s-01 ~]# curl -I 10.109.145.140:8080
HTTP/1.1 200 OK
Date: Wed, 06 May 2020 07:24:57 GMT
Server: Apache/2.4.41 (Unix)
Last-Modified: Mon, 11 Jun 2007 18:53:14 GMT
ETag: "2d-432a5e4a73a80"
Accept-Ranges: bytes
Content-Length: 45
Content-Type: text/html

[root@k8s-01 ~]#

获取服务详情以确认Cluster IP指向的后端Pod IP信息

[root@k8s-01 ~]# kubectl describe services httpd-service
Name:              httpd-service
Namespace:         default
Labels:            <none>
Annotations:       kubectl.kubernetes.io/last-applied-configuration:
                     {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"name":"httpd-service","namespace":"default"},"spec":{"ports":[{"port":80...
Selector:          run=httpd
Type:              ClusterIP
IP:                10.109.145.140
Port:              <unset>  8080/TCP
TargetPort:        80/TCP
Endpoints:         10.244.1.3:80,10.244.1.4:80,10.244.2.3:80
Session Affinity:  None
Events:            <none>
[root@k8s-01 ~]#
[root@k8s-01 ~]# kubectl get endpoints httpd-service
NAME            ENDPOINTS                                   AGE
httpd-service   10.244.1.3:80,10.244.1.4:80,10.244.2.3:80   5m23s
[root@k8s-01 ~]#
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