1.工作原理
image.png
master節(jié)點(diǎn)（Control Plane【控制面板】）：master節(jié)點(diǎn)控制整個集群
master節(jié)點(diǎn)上有一些核心組件：
Controller Manager：控制管理器
etcd：鍵值數(shù)據(jù)庫（redis）【記賬本，記事本】
scheduler：調(diào)度器
api server：api網(wǎng)關(guān)（所有的控制都需要通過api-server）
node節(jié)點(diǎn)（worker工作節(jié)點(diǎn)）：
kubelet（監(jiān)工）：每一個node節(jié)點(diǎn)上必須安裝的組件。
kube-proxy：代理。代理網(wǎng)絡(luò)
部署一個應(yīng)用剪菱？
程序員：調(diào)用CLI告訴master，我們現(xiàn)在要部署一個tomcat應(yīng)用
程序員的所有調(diào)用都先去master節(jié)點(diǎn)的網(wǎng)關(guān)api-server症汹。這是matser的唯一入口（mvc模式中的c層）
收到的請求先交給master的api-server宾肺。由api-server交給controller-mannager進(jìn)行控制
controller-mannager 進(jìn)行 應(yīng)用部署
controller-mannager 會生成一次部署信息溯饵。 tomcat --image:tomcat6 --port 8080 ,真正不部署應(yīng)用
部署信息被記錄在etcd中
scheduler調(diào)度器從etcd數(shù)據(jù)庫中，拿到要部署的應(yīng)用锨用，開始調(diào)度丰刊。看哪個節(jié)點(diǎn)合適增拥，
scheduler把算出來的調(diào)度信息再放到etcd中
每一個node節(jié)點(diǎn)的監(jiān)控kubelet啄巧，隨時和master保持聯(lián)系的（給api-server發(fā)送請求不斷獲取最新數(shù)據(jù)），所有節(jié)點(diǎn)的kubelet就會從master
假設(shè)node2的kubelet最終收到了命令跪者，要部署棵帽。
kubelet就自己run一個應(yīng)用在當(dāng)前機(jī)器上，隨時給master匯報(bào)當(dāng)前應(yīng)用的狀態(tài)信息渣玲，分配ip
node和master是通過master的api-server聯(lián)系的
每一個機(jī)器上的kube-proxy能知道集群的所有網(wǎng)絡(luò)逗概。只要node訪問別人或者別人訪問node，node上的kube-proxy網(wǎng)絡(luò)代理自動計(jì)算進(jìn)行流量轉(zhuǎn)發(fā)
image.png
工作節(jié)點(diǎn)
image.pngPod：
docker run 啟動的是一個
container（容器）忘衍，容器是docker的基本單位逾苫，一個應(yīng)用是一個容器
kubelet run 啟動的一個應(yīng)用稱為一個Pod；Pod是k8s的基本單位枚钓。
Pod是容器的一個再封裝
一個容器往往代表不了一個基本應(yīng)用铅搓。博客（php+mysql合起來完成）
準(zhǔn)備一個Pod 可以包含多個 container；一個Pod代表一個基本的應(yīng)用搀捷。
IPod（看電影星掰、聽音樂、玩游戲）【一個基本產(chǎn)品嫩舟，原子】氢烘；
Pod（music container、movie container）【一個基本產(chǎn)品家厌，原子的】
Kubelet：監(jiān)工播玖，負(fù)責(zé)交互master的api-server以及當(dāng)前機(jī)器的應(yīng)用啟停等，在master機(jī)器就是master的小助手饭于。每一臺機(jī)器真正干活的都是這個 Kubelet
Kube-proxy：
其他：
-
集群交互原理
1619075921614.png想讓k8s部署一個tomcat蜀踏？
0、開機(jī)默認(rèn)所有節(jié)點(diǎn)的kubelet掰吕、master節(jié)點(diǎn)的scheduler（調(diào)度器）果覆、controller-manager（控制管理器）一直監(jiān)聽master的api-server發(fā)來的事件變化（for ::）
1、程序員使用命令行工具： kubectl 殖熟； kubectl create deploy tomcat --image=tomcat8（告訴master讓集群使用tomcat8鏡像随静，部署一個tomcat應(yīng)用）
2、kubectl命令行內(nèi)容發(fā)給api-server，api-server保存此次創(chuàng)建信息到etcd
3燎猛、etcd給api-server上報(bào)事件恋捆，說剛才有人給我里面保存一個信息。（部署Tomcat[deploy]）
4重绷、controller-manager監(jiān)聽到api-server的事件沸停，是 （部署Tomcat[deploy]）
5、controller-manager 處理這個 （部署Tomcat[deploy]）的事件昭卓。controller-manager會生成Pod的部署信息【pod信息】
6愤钾、controller-manager 把Pod的信息交給api-server，再保存到etcd
7候醒、etcd上報(bào)事件【pod信息】給api-server能颁。
8、scheduler專門監(jiān)聽 【pod信息】 倒淫，拿到 【pod信息】的內(nèi)容伙菊，計(jì)算，看哪個節(jié)點(diǎn)合適部署這個Pod【pod調(diào)度過后的信息（node: node-02）】敌土，
9镜硕、scheduler把 【pod調(diào)度過后的信息（node: node-02）】交給api-server保存給etcd
10、etcd上報(bào)事件【pod調(diào)度過后的信息（node: node-02）】返干，給api-server
11兴枯、其他節(jié)點(diǎn)的kubelet專門監(jiān)聽 【pod調(diào)度過后的信息（node: node-02）】 事件，集群所有節(jié)點(diǎn)kubelet從api-server就拿到了 【pod調(diào)度過后的信息（node: node-02）】 事件
12矩欠、每個節(jié)點(diǎn)的kubelet判斷是否屬于自己的事情财剖；node-02的kubelet發(fā)現(xiàn)是他的事情
13、node-02的kubelet啟動這個pod癌淮。匯報(bào)給master當(dāng)前啟動好的所有信息
-
k8s集群安裝
準(zhǔn)備3臺機(jī)器
| 實(shí)例 | 公網(wǎng)ip | 內(nèi)網(wǎng)ip | 節(jié)點(diǎn)類型 |
|---|---|---|---|
| i-wz9gesw0qtscfefs2xyl | 47.106.12.54 | 172.27.228.2 | master |
| i-wz9gesw0qtscfefs2xyn | 120.79.96.89 | 172.27.209.121 | worker1 |
| i-wz9gesw0qtscfefs2xym | 120.24.212.245 | 172.27.209.122 | worker2 |
安裝方式
二進(jìn)制安裝（建議生產(chǎn)環(huán)境使用）
kebuadm引導(dǎo)方式（官方推薦）
大致流程:準(zhǔn)備3臺服務(wù)器內(nèi)網(wǎng)互通
安裝Docker容器化環(huán)境
安裝kebernetes: 3臺機(jī)器安裝核心組件(kebuadm(創(chuàng)建集群的引導(dǎo)工具)躺坟、kubelet)、kubectl(程序員用的命令行)
安裝前置環(huán)境
關(guān)閉防火墻： 如果是云服務(wù)器该默，需要設(shè)置安全組策略放行端口
https://kubernetes.io/zh/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#check-required-ports
systemctl stop firewalld
systemctl disable firewalld修改 hostname
| ip | hostName |
|---|---|
47.106.12.54 |
hostnamectl set-hostname k8s-01
|
120.79.96.89 |
hostnamectl set-hostname k8s-02
|
120.24.212.245 |
hostnamectl set-hostname k8s-03
|
查看修改結(jié)果
[root@iZwz9gesw0qtscfefs2xynZ ~]# hostnamectl status
Static hostname: k8s-02
Icon name: computer-vm
Chassis: vm
Machine ID: 20200914151306980406746494236010
Boot ID: 6b72c6ee16094f48b50f681a7f0110b5
Virtualization: kvm
Operating System: CentOS Linux 7 (Core)
CPE OS Name: cpe:/o:centos:centos:7
Kernel: Linux 3.10.0-1127.19.1.el7.x86_64
Architecture: x86-64
設(shè)置hostname解析
echo "127.0.0.1 $(hostname)" >> /etc/hosts
關(guān)閉selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0
關(guān)閉 swap：
swapoff -a
sed -ri 's/.*swap.*/#&/' /etc/fstab
允許 iptables 檢查橋接流量
https://kubernetes.io/zh/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#%E5%85%81%E8%AE%B8-iptables-%E6%A3%80%E6%9F%A5%E6%A1%A5%E6%8E%A5%E6%B5%81%E9%87%8F
開啟br_netfilter
sudo modprobe br_netfilter
確認(rèn)下
lsmod | grep br_netfilter
安裝docker
sudo yum remove docker*
sudo yum install -y yum-utils
配置docker yum 源
sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
安裝docker 19.03.9
yum install -y docker-ce-3:19.03.9-3.el7.x86_64 docker-ce-cli-3:19.03.9-3.el7.x86_64 containerd.io
安裝docker 19.03.9 docker-ce 19.03.9
yum install -y docker-ce-19.03.9-3 docker-ce-cli-19.03.9 containerd.io
啟動服務(wù)
systemctl start docker
systemctl enable docker
配置加速
sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
"registry-mirrors": ["https://82m9ar63.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker
安裝k8s
配置K8S的yum源
vim /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
1.卸載舊版本
yum remove -y kubelet kubeadm kubectl
2.查看可以安裝的版本
yum list kubelet --showduplicates | sort -r
3.# 安裝kubelet瞳氓、kubeadm策彤、kubectl 指定版本
yum install -y kubelet-1.21.0 kubeadm-1.21.0 kubectl-1.21.0
4.開機(jī)啟動kubelet
systemctl enable kubelet && systemctl start kubelet
5.查看kubelet狀態(tài)
[root@k8s-01 ~]# systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled; vendor preset: disabled)
Drop-In: /usr/lib/systemd/system/kubelet.service.d
└─10-kubeadm.conf
Active: activating (auto-restart) (Result: exit-code) since 五 2023-10-06 10:17:05 CST; 8s ago
Docs: https://kubernetes.io/docs/
Process: 3854 ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS (code=exited, status=1/FAILURE)
Main PID: 3854 (code=exited, status=1/FAILURE)
10月 06 10:17:05 k8s-01 systemd[1]: Unit kubelet.service entered failed state.
10月 06 10:17:05 k8s-01 systemd[1]: kubelet.service failed.
初始化matsre節(jié)點(diǎn)（master執(zhí)行）
1.查看需要的鏡像
[root@k8s-01 ~]# kubeadm config images list
W1006 10:22:19.236666 4076 version.go:102] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get "https://cdn.dl.k8s.io/release/stable-1.txt": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
W1006 10:22:19.236766 4076 version.go:103] falling back to the local client version: v1.21.0
k8s.gcr.io/kube-apiserver:v1.21.0
k8s.gcr.io/kube-controller-manager:v1.21.0
k8s.gcr.io/kube-scheduler:v1.21.0
k8s.gcr.io/kube-proxy:v1.21.0
k8s.gcr.io/pause:3.4.1
k8s.gcr.io/etcd:3.4.13-0
k8s.gcr.io/coredns/coredns:v1.8.0
2.配置鏡像
vi images.sh
#!/bin/bash
images=(
kube-apiserver:v1.21.0
kube-proxy:v1.21.0
kube-controller-manager:v1.21.0
kube-scheduler:v1.21.0
coredns:v1.8.0
etcd:3.4.13-0
pause:3.4.1
)
for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/$imageName
done
- 執(zhí)行腳本
chmod +x images.sh && ./images.sh
4.查看下載的images
[root@k8s-01 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/kube-apiserver v1.21.0 4d217480042e 2 years ago 126MB
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/kube-proxy v1.21.0 38ddd85fe90e 2 years ago 122MB
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/kube-controller-manager v1.21.0 09708983cc37 2 years ago 120MB
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/kube-scheduler v1.21.0 62ad3129eca8 2 years ago 50.6MB
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/pause 3.4.1 0f8457a4c2ec 2 years ago 683kB
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/coredns v1.8.0 296a6d5035e2 2 years ago 42.5MB
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/etcd 3.4.13-0 0369cf4303ff 3 years ago 253MB
注意1.21.0版本的k8s coredns鏡像比較特殊栓袖，結(jié)合阿里云需要特殊處理，重新打標(biāo)簽
docker tag registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/coredns:v1.8.0 registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/coredns/coredns:v1.8.0
########kubeadm init 一個master########################
########kubeadm join 其他worker########################
kubeadm init \ --apiserver-advertise-address=172.27.228.2 \ --image-repository registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images \ --kubernetes-version v1.21.0 \ --service-cidr=10.96.0.0/16 \ --pod-network-cidr=192.168.0.0/16
注意：pod-cidr與service-cidr
cidr 無類別域間路由（Classless Inter-Domain Routing店诗、CIDR）
指定一個網(wǎng)絡(luò)可達(dá)范圍 pod的子網(wǎng)范圍+service負(fù)載均衡網(wǎng)絡(luò)的子網(wǎng)范圍+本機(jī)ip的子網(wǎng)范圍不能有重復(fù)域
安裝完成提示
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
Alternatively, if you are the root user, you can run:
export KUBECONFIG=/etc/kubernetes/admin.conf
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 172.27.228.2:6443 --token aw37ip.t9nsblzyxe49tsco \
--discovery-token-ca-cert-hash sha256:3a74d9f5336c804276f1b7bc494027b26b7a498ae1a5a396b35a92ce0b3411a1
按照如上提示操作
1.init完成后裹刮，復(fù)制相關(guān)文件夾
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
2.導(dǎo)出環(huán)境變量
export KUBECONFIG=/etc/kubernetes/admin.conf
3.部署一個pod網(wǎng)絡(luò)
kubectl apply -f https://docs.projectcalico.org/v3.20/manifests/calico.yaml
4.獲取集群中所有部署好的應(yīng)用pod
[root@k8s-01 ~]# kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-kube-controllers-594649bd75-64s9q 0/1 CrashLoopBackOff 1 3m8s
kube-system calico-node-bz9f8 0/1 Init:2/3 0 3m20s
kube-system coredns-b98666c6d-fz7cr 1/1 Running 0 34h
kube-system coredns-b98666c6d-g64zs 1/1 Running 0 34h
kube-system etcd-k8s-01 1/1 Running 0 34h
kube-system kube-apiserver-k8s-01 1/1 Running 0 34h
kube-system kube-controller-manager-k8s-01 1/1 Running 0 34h
kube-system kube-proxy-tjsrb 1/1 Running 0 34h
kube-system kube-scheduler-k8s-01 1/1 Running 0 34h
[root@k8s-01 ~]#
5.查看集群所有機(jī)器的狀態(tài)
[root@k8s-01 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-01 Ready control-plane,master 34h v1.21.
初始化worker節(jié)點(diǎn)
1.在master節(jié)點(diǎn)執(zhí)行命令
kubeadm token create --print-join-command
[root@k8s-01 ~]# kubeadm token create --print-join-command
kubeadm join 172.27.228.2:6443 --token r1hj55.nllrkk4irqwkgpl2 --discovery-token-ca-cert-hash sha256:3a74d9f5336c804276f1b7bc494027b26b7a498ae1a5a396b35a92ce0b3411a1
2.將輸出結(jié)果拿到worker節(jié)點(diǎn)執(zhí)行
[root@k8s-02 ~]# kubeadm join 172.27.228.2:6443 --token r1hj55.nllrkk4irqwkgpl2 --discovery-token-ca-cert-hash sha256:3a74d9f5336c804276f1b7bc494027b26b7a498ae1a5a396b35a92ce0b3411a1
[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 -o yaml'
[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.
3.在master節(jié)點(diǎn)查看nodes節(jié)點(diǎn)(驗(yàn)證集群是否成功)
[root@k8s-01 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-01 Ready control-plane,master 34h v1.21.0
k8s-02 Ready <none> 7m29s v1.21.0
k8s-03 Ready <none> 5m16s v1.21.0
4.給節(jié)點(diǎn)打標(biāo)簽
k8s中萬物皆對象，node:機(jī)器 pod:應(yīng)用容器
[root@k8s-01 ~]# kubectl label node k8s-03 node-role.kubernetes.io/worker3='worker-03'
node/k8s-03 labeled
[root@k8s-01 ~]# kubectl label node k8s-02 node-role.kubernetes.io/worker2='worker-02'
node/k8s-02 labeled
[root@k8s-01 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-01 Ready control-plane,master 34h v1.21.0
k8s-02 Ready worker2 23m v1.21.0
k8s-03 Ready worker3 21m v1.21.0
5.設(shè)置ipvs模式
k8s集群庞瘸，機(jī)器重啟后會自動加入集群捧弃，master重啟會自動再加入即去控制中心。k8s集群默認(rèn)是iptables，性能下降（kube-proxy會在集群之間同步iptables的內(nèi)容）
獲取集群中的所有資源
[root@k8s-01 ~]# kubectl get all -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system pod/calico-kube-controllers-594649bd75-64s9q 1/1 Running 5 75m
kube-system pod/calico-node-59gnt 1/1 Running 0 53m
kube-system pod/calico-node-89b8t 1/1 Running 0 55m
kube-system pod/calico-node-bz9f8 1/1 Running 0 75m
kube-system pod/coredns-b98666c6d-fz7cr 1/1 Running 0 35h
kube-system pod/coredns-b98666c6d-g64zs 1/1 Running 0 35h
kube-system pod/etcd-k8s-01 1/1 Running 0 35h
kube-system pod/kube-apiserver-k8s-01 1/1 Running 0 35h
kube-system pod/kube-controller-manager-k8s-01 1/1 Running 0 35h
kube-system pod/kube-proxy-74clv 1/1 Running 0 53m
kube-system pod/kube-proxy-rfth6 1/1 Running 0 55m
kube-system pod/kube-proxy-tjsrb 1/1 Running 0 35h
kube-system pod/kube-scheduler-k8s-01 1/1 Running 0 35h
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 35h
kube-system service/kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 35h
NAMESPACE NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
kube-system daemonset.apps/calico-node 3 3 3 3 3 kubernetes.io/os=linux 34h
kube-system daemonset.apps/kube-proxy 3 3 3 3 3 kubernetes.io/os=linux 35h
NAMESPACE NAME READY UP-TO-DATE AVAILABLE AGE
kube-system deployment.apps/calico-kube-controllers 1/1 1 1 34h
kube-system deployment.apps/coredns 2/2 2 2 35h
NAMESPACE NAME DESIRED CURRENT READY AGE
kube-system replicaset.apps/calico-kube-controllers-594649bd75 1 1 1 75m
kube-system replicaset.apps/calico-kube-controllers-5d4b78db86 0 0 0 34h
kube-system replicaset.apps/coredns-b98666c6d 2 2 2 35h
修改kube-proxy的配置文件违霞，修改mode為ipvs嘴办。默認(rèn)為iptables，但是集群大了之后就很慢
kubectl edit cm kube-proxy -n kube-system, 修改mode="ipvs"
image.png
重啟kube-proxy(殺死舊的买鸽，會自動加入新配置的kube-proxy)
[root@k8s-01 ~]# kubectl delete pod kude-proxy-74clv -n kube-system
Error from server (NotFound): pods "kude-proxy-74clv" not found
[root@k8s-01 ~]# kubectl delete pod kube-proxy-74clv -n kube-system
pod "kube-proxy-74clv" deleted
[root@k8s-01 ~]# kubectl delete pod kube-proxy-rfth6 -n kube-system
pod "kube-proxy-rfth6" deleted
[root@k8s-01 ~]# kubectl delete pod kube-proxy-tjsrb -n kube-system
pod "kube-proxy-tjsrb" deleted
[root@k8s-01 ~]# kubectl get pods -A | grep kube-proxy
kube-system kube-proxy-gcxvl 1/1 Running 0 3m22s
kube-system kube-proxy-gqkcg 1/1 Running 0 2m49s
kube-system kube-proxy-jzj9p 1/1 Running 0 3m4s
查看k8s下所有的資源
kubectl api-resources --namespace=true
[root@k8s-01 ~]# kubectl api-resources
NAME SHORTNAMES APIVERSION NAMESPACED KIND
bindings v1 true Binding
componentstatuses cs v1 false ComponentStatus
configmaps cm v1 true ConfigMap
endpoints ep v1 true Endpoints
events ev v1 true Event
limitranges limits v1 true LimitRange
namespaces ns v1 false Namespace
nodes no v1 false Node
persistentvolumeclaims pvc v1 true PersistentVolumeClaim
persistentvolumes pv v1 false PersistentVolume
pods po v1 true Pod
podtemplates v1 true PodTemplate
replicationcontrollers rc v1 true ReplicationController
resourcequotas quota v1 true ResourceQuota
k8s輸出詳細(xì)描述信息
[root@k8s-01 ~]# kubectl describe pod my-nginx
Name: my-nginx-6b74b79f57-grk69
Namespace: default
Priority: 0
Node: k8s-02/172.27.209.121
Start Time: Sat, 07 Oct 2023 22:45:36 +0800
Labels: app=my-nginx
pod-template-hash=6b74b79f57
Annotations: cni.projectcalico.org/containerID: ab0f6852275d9cdf43745b7b6af6bb846714b7ccdb874febe7544a8091bdd171
cni.projectcalico.org/podIP: 192.168.179.1/32
cni.projectcalico.org/podIPs: 192.168.179.1/32
Status: Running
IP: 192.168.179.1
IPs:
IP: 192.168.179.1
Controlled By: ReplicaSet/my-nginx-6b74b79f57
Containers:
nginx:
Container ID: docker://54cfa0f83b91f298427a8e4371ebdfcd7f9580bad4f7e4b65e4c36c1361db276
Image: nginx
Image ID: docker-pullable://nginx@sha256:0d17b565c37bcbd895e9d92315a05c1c3c9a29f762b011a10c54a66cd53c9b31
Port: <none>
Host Port: <none>
State: Running
Started: Sat, 07 Oct 2023 22:45:46 +0800
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-w9zms (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
kube-api-access-w9zms:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events: <none>
創(chuàng)建(部署)一個k8s應(yīng)用
[root@k8s-01 ~]# kubectl create deploy my-nginx --image=nginx
deployment.apps/my-nginx created
[root@k8s-01 ~]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
my-nginx-6b74b79f57-grk69 1/1 Running 0 16s 192.168.179.1 k8s-02 <none> <none>
[root@k8s-01 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
my-nginx-6b74b79f57-grk69 1/1 Running 0 2m16s 192.168.179.1 k8s-02 <none> <none>
[root@k8s-01 ~]# kubectl exec -it my-nginx-6b74b79f57-grk69 -- /bin/bash
k8s基礎(chǔ)
docker是每一個worker節(jié)點(diǎn)的運(yùn)行時環(huán)境
kubelet負(fù)責(zé)控制所有容器的啟動停止涧郊，保證節(jié)點(diǎn)正常工作，以及幫助節(jié)點(diǎn)交互master
master節(jié)點(diǎn)的關(guān)鍵組件1.kubelet(監(jiān)工):所有節(jié)點(diǎn)必備眼五，控制這個節(jié)點(diǎn)的所有pod的生命周期以及與api-server交互等工作
2.kube-api-server:負(fù)責(zé)接收所有請求妆艘。集群內(nèi)對集群的任何修改都是通過命令行、UI把請求發(fā)給api-server才能執(zhí)行的看幼。api-server是整個集群對內(nèi)批旺、對外的唯一入口。不包含后來我們部署應(yīng)用暴露端口的方式
3.kube-proxy:整個節(jié)點(diǎn)的網(wǎng)絡(luò)流量負(fù)責(zé)
4.cri: 容器運(yùn)行時環(huán)境
worker節(jié)點(diǎn)的關(guān)鍵組件1.kubelet(監(jiān)工):所有節(jié)點(diǎn)必備诵姜，控制這個節(jié)點(diǎn)的所有pod的生命周期以及與api-server交互等工作
2.kube-proxy:整個節(jié)點(diǎn)的網(wǎng)絡(luò)流量負(fù)責(zé)
3.cri: 容器運(yùn)行時環(huán)境
應(yīng)用部署
1.
kubectl create deploy xxxxxx：命令行會給api-server發(fā)送要部署xxx的請求
2.api-server把這個請求保存到etcd
kubectl create 幫我們創(chuàng)建k8s集群中的一些對象
kubectl create --help
kubectl create deployment 這次部署的名字 --image=應(yīng)用的鏡像
最終在一個機(jī)器上有pod汽煮、這個pod其實(shí)本質(zhì)里面就是一個容器k8s_nginx_my-nginx-6b74b79f57-snlr4_default_dbeac79e-1ce9-42c9-bc59-c8ca0412674b_0
k8s_鏡像(nginx)pod名(my-nginx-6b74b79f57-snlr4)容器名(default_dbeac79e-1ce9-42c9-bc59-c8ca0412674b_0)
Create a deployment with command
kubectl create deployment my-nginx --image=nginx -- date
Create a deployment named my-nginx that runs the nginx image with 3 replicas
kubectl create deployment my-nginx --image=nginx --replicas=3
Create a deployment named my-nginx that runs the nginx image and expose port 80.
kubectl create deployment my-nginx --image=nginx --port=80Deployment（部署）
1.在k8s中，通過發(fā)布 Deployment茅诱，可以創(chuàng)建應(yīng)用程序 (docker image) 的實(shí)例 (docker container)逗物，這個實(shí)例會被包含在稱為 Pod 的概念中，Pod 是 k8s 中最小可管理單元
2.在 k8s 集群中發(fā)布 Deployment 后瑟俭，Deployment 將指示 k8s 如何創(chuàng)建和更新應(yīng)用程序的實(shí)例翎卓，master 節(jié)點(diǎn)將應(yīng)用程序?qū)嵗{(diào)度到集群中的具體的節(jié)點(diǎn)上
3.創(chuàng)建應(yīng)用程序?qū)嵗螅琄ubernetes Deployment Controller 會持續(xù)監(jiān)控這些實(shí)例摆寄。如果運(yùn)行實(shí)例的 worker 節(jié)點(diǎn)關(guān)機(jī)或被刪除失暴，則 Kubernetes Deployment Controller 將在群集中資源最優(yōu)的另一個 worker 節(jié)點(diǎn)上重新創(chuàng)建一個新的實(shí)例。這提供了一種自我修復(fù)機(jī)制來解決機(jī)器故障或維護(hù)問題
4.在容器編排之前的時代微饥，各種安裝腳本通常用于啟動應(yīng)用程序逗扒，但是不能夠使應(yīng)用程序從機(jī)器故障中恢復(fù)。通過創(chuàng)建應(yīng)用程序?qū)嵗⒋_保它們在集群節(jié)點(diǎn)中的運(yùn)行實(shí)例個數(shù)欠橘，Kubernetes Deployment 提供了一種完全不同的方式來管理應(yīng)用程序
5.Deployment 處于 master 節(jié)點(diǎn)上矩肩，通過發(fā)布 Deployment，master 節(jié)點(diǎn)會選擇合適的 worker 節(jié)點(diǎn)創(chuàng)建 Container（即圖中的正方體）肃续，Container 會被包含在 Pod （即藍(lán)色圓圈）里
k8s擴(kuò)縮容
[root@k8s-01 ~]# kubectl get deploy,pod
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/my-nginx 1/1 1 1 36h
NAME READY STATUS RESTARTS AGE
pod/my-nginx-6b74b79f57-grk69 1/1 Running 0 36h
[root@k8s-01 ~]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
my-nginx-6b74b79f57-grk69 1/1 Running 0 36h 192.168.179.1 k8s-02 <none> <none>
[root@k8s-01 ~]# kubectl scale --replicas=3 deploy my-nginx
deployment.apps/my-nginx scaled
[root@k8s-01 ~]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
my-nginx-6b74b79f57-6lllw 1/1 Running 0 67s 192.168.179.2 k8s-02 <none> <none>
my-nginx-6b74b79f57-grk69 1/1 Running 0 36h 192.168.179.1 k8s-02 <none> <none>
my-nginx-6b74b79f57-w2gtf 1/1 Running 0 67s 192.168.165.193 k8s-03 <none> <none>
[root@k8s-01 ~]#
[root@k8s-01 ~]# watch -n 1 kubectl get deploy,pod
Every 1.0s: kubectl get deploy,pod Mon Oct 9 11:48:52 2023
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/my-nginx 3/3 3 3 37h
NAME READY STATUS RESTARTS AGE
pod/my-nginx-6b74b79f57-6lllw 1/1 Running 0 10m
pod/my-nginx-6b74b79f57-grk69 1/1 Running 0 37h
pod/my-nginx-6b74b79f57-w2gtf 1/1 Running 0 10m
# 縮容
[root@k8s-01 ~]# kubectl scale --replicas=1 deploy my-nginx
[root@k8s-01 ~]# watch -n 1 kubectl get deploy,pod
Every 1.0s: kubectl get deploy,pod Mon Oct 9 11:50:53 2023
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/my-nginx 1/1 1 1 37h
NAME READY STATUS RESTARTS AGE
pod/my-nginx-6b74b79f57-w2gtf 1/1 Running 0 12m
service和label
Service是通過一組Pod路由通信黍檩，Service是一種抽象，它允許pod死亡并在kubernetes中復(fù)制始锚，而不會影響應(yīng)用程序刽酱，在依賴的Pod之間進(jìn)行發(fā)現(xiàn)和路由是由Kubernetes Service處理的。Service匹配一組Pod是使用
標(biāo)簽(Label)和選擇器(Selector),他們是允許對Kubernetes中的對象進(jìn)行邏輯操作的一種分組原語瞧捌。標(biāo)簽(Label)是附加在對象上的鍵值對棵里，可以以多種方式使用：指定用于開發(fā)润文、測試和生產(chǎn)的對象
嵌入版本標(biāo)簽
使用Label將對象分類
[root@k8s-01 ~]# kubectl get pod --show-labels
NAME READY STATUS RESTARTS AGE LABELS
my-nginx-6b74b79f57-w2gtf 1/1 Running 0 64m app=my-nginx,pod-template-hash=6b74b79f57
kubectl expose
1.type=ClusterIP方式
[root@k8s-01 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/my-nginx-6b74b79f57-5lv6s 1/1 Running 0 11m
pod/my-nginx-6b74b79f57-p8rld 1/1 Running 0 11m
pod/my-nginx-6b74b79f57-w2gtf 1/1 Running 0 82m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 3d1h
service/my-nginx ClusterIP 10.96.239.231 <none> 8081/TCP 22s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/my-nginx 3/3 3 3 38h
NAME DESIRED CURRENT READY AGE
replicaset.apps/my-nginx-6b74b79f57 3 3 3 38h
[root@k8s-01 ~]# curl 10.96.239.231:8081
[root@k8s-01 ~]# kubectl delete service/my-nginx
service "my-nginx" deleted
2.type=NodePort
[root@k8s-01 ~]# kubectl expose deploy my-nginx --port=8081 --target-port=80 --type=NodePort
service/my-nginx exposed
[root@k8s-01 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/my-nginx-6b74b79f57-5lv6s 1/1 Running 0 29m
pod/my-nginx-6b74b79f57-p8rld 1/1 Running 0 29m
pod/my-nginx-6b74b79f57-w2gtf 1/1 Running 0 100m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 3d2h
service/my-nginx NodePort 10.96.97.250 <none> 8081:31819/TCP 42s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/my-nginx 3/3 3 3 38h
NAME DESIRED CURRENT READY AGE
replicaset.apps/my-nginx-6b74b79f57 3 3 3 38h
[root@k8s-01 ~]# netstat -nlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:10248 0.0.0.0:* LISTEN 7201/kubelet
tcp 0 0 127.0.0.1:10249 0.0.0.0:* LISTEN 9838/kube-proxy
tcp 0 0 0.0.0.0:31819 0.0.0.0:* LISTEN 9838/kube-proxy
[root@k8s-01 ~]# netstat -nlpt | grep 31819
tcp 0 0 0.0.0.0:31819 0.0.0.0:* LISTEN 9838/kube-proxy
[root@k8s-02 ~]# netstat -nlpt | grep 31819
tcp 0 0 0.0.0.0:31819 0.0.0.0:* LISTEN 23576/kube-proxy
[root@k8s-03 ~]# netstat -nlpt | grep 31819
tcp 0 0 0.0.0.0:31819 0.0.0.0:* LISTEN 12999/kube-proxy
[root@k8s-01 ~]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
my-nginx 3/3 3 3 38h
[root@k8s-01 ~]#
訪問方式:公網(wǎng)ip+端口
http://47.106.12.54:31819/
擴(kuò)縮容
目標(biāo)
用kubectl擴(kuò)縮應(yīng)用程序
擴(kuò)縮一個Deployment我們創(chuàng)建一個Deployment，然后通過服務(wù)提供訪問Pod的方式殿怜，我們發(fā)布的Deployment只創(chuàng)建了一個Pod來運(yùn)行我們的應(yīng)用程序典蝌，當(dāng)流量增加時，我們需要對應(yīng)用程序進(jìn)行伸縮操作以滿足系統(tǒng)性能需求
image.png擴(kuò)展
擴(kuò)容的Pod會自動加入到它之前存在的Service（負(fù)載均衡網(wǎng)絡(luò)）
kubectl scale --replicas=3 deployment tomcat6
持續(xù)觀測結(jié)果
watch kubectl get pods -o wide執(zhí)行滾動升級
目標(biāo)： 使用kubectl執(zhí)行滾動更新
滾動更新允許通過使用新的實(shí)例逐步更新Pod實(shí)例從而實(shí)現(xiàn)Deployments更新头谜，停機(jī)時間為零
應(yīng)用升級: tomcat:alpine赠法、tomcat:jre8-alpine
kubectl set image deployment/my-nginx2 nginx=nginx:1.9.1
聯(lián)合jenkins 形成持續(xù)集成，灰度發(fā)布功能
kubectl set image deployment.apps/tomcat6 tomcat=tomcat:jre8-alpine
可以攜帶--record參數(shù)乔夯，記錄變更
回滾升級
查看歷史記錄
kubectl rollout history deployment.apps/tomcat6
kubectl rollout history deploy tomcat6
回滾到指定版本
kubectl rollout undo deployment.apps/tomcat6 --to-revision=1
kubectl rollout undo deploy tomcat6 --to-revision=1
為image做升級
[root@k8s-01 ~]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
my-nginx 3/3 3 3 2d12h
[root@k8s-01 ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
my-nginx-6b74b79f57-5lv6s 1/1 Running 0 22h
my-nginx-6b74b79f57-p8rld 1/1 Running 0 22h
my-nginx-6b74b79f57-w2gtf 1/1 Running 0 24h
[root@k8s-01 ~]# kubectl get pod my-nginx-6b74b79f57-w2gtf -o yaml | grep container
cni.projectcalico.org/containerID: 00ec829ae6d6db562b71761b2035e9b0fc47128cb22e7237622f01686fe8bef5
containers:
containerStatuses:
- containerID: docker://428d2e4fb3c615f46b0d15fd323de19d70a7b24507e131b3e6f759cfa9c8f116
[root@k8s-01 ~]# kubectl get pod my-nginx-6b74b79f57-w2gtf -o yaml | grep name
name: my-nginx-6b74b79f57-w2gtf
namespace: default
name: my-nginx-6b74b79f57
name: nginx
name: kube-api-access-lz4mb
- name: kube-api-access-lz4mb
name: kube-root-ca.crt
fieldPath: metadata.namespace
path: namespace
name: nginx
[root@k8s-01 ~]# kubectl get pod my-nginx-6b74b79f57-w2gtf -o yaml | grep image
- image: nginx
imagePullPolicy: Always
image: nginx:latest
imageID: docker-pullable://nginx@sha256:0d17b565c37bcbd895e9d92315a05c1c3c9a29f762b011a10c54a66cd53c9b31
[root@k8s-01 ~]# kubectl set image deploy my-nginx nginx=nginx:1.9.2 --record
deployment.apps/my-nginx image updated
watch kubectl get pod
image.png
image.png
image.png
image.png
k8s回滾到以前的版本
1.查看歷史記錄
[root@k8s-01 ~]# kubectl rollout history deploy my-nginx
deployment.apps/my-nginx
REVISION CHANGE-CAUSE
1 <none>
2 <none>
3 kubectl set image deploy my-nginx nginx=nginx:1.9.2 --record=true
2.回滾到指定版本
[root@k8s-01 ~]# kubectl rollout undo deploy my-nginx --to-revision=1
deployment.apps/my-nginx rolled back
k8s對象描述文件
聲明式API砖织， 對象描述文件的方式（Pod -> yaml, Deploy -> yaml, Service -> yaml）, kubectl apply -f xxx.yaml
部署一個Deploy
apiVersion: apps/v1 #與k8s集群版本有關(guān)，使用 kubectl api-versions 即可查看當(dāng)前集群支持的版本
kind: Deployment #該配置的類型末荐，我們使用的是 Deployment
metadata: #譯名為元數(shù)據(jù)侧纯，即 Deployment 的一些基本屬性和信息
name: nginx-deployment #Deployment 的名稱
labels: #標(biāo)簽，可以靈活定位一個或多個資源甲脏，其中key和value均可自定義眶熬，可以定義多組，目前不需要理解
app: nginx #為該Deployment設(shè)置key為app块请，value為nginx的標(biāo)簽
spec: #這是關(guān)于該Deployment的描述娜氏，可以理解為你期待該Deployment在k8s中如何使用
replicas: 1 #使用該Deployment創(chuàng)建一個應(yīng)用程序?qū)嵗? selector: #標(biāo)簽選擇器，與上面的標(biāo)簽共同作用墩新，目前不需要理解
matchLabels: #選擇包含標(biāo)簽app:nginx的資源
app: nginx
template: #這是選擇或創(chuàng)建的Pod的模板
metadata: #Pod的元數(shù)據(jù)
labels: #Pod的標(biāo)簽贸弥，上面的selector即選擇包含標(biāo)簽app:nginx的Pod
app: nginx
spec: #期望Pod實(shí)現(xiàn)的功能（即在pod中部署）
containers: #生成container，與docker中的container是同一種
- name: nginx #container的名稱
image: nginx:1.7.9 #使用鏡像nginx:1.7.9創(chuàng)建container海渊，該container默認(rèn)80端口可訪問
通過yaml部署前先刪除舊的部署
[root@k8s-01 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/my-nginx-6b74b79f57-2qftn 1/1 Running 0 7h25m
pod/my-nginx-6b74b79f57-7hs8g 1/1 Running 0 7h25m
pod/my-nginx-6b74b79f57-9q5q5 1/1 Running 0 7h25m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 4d8h
service/my-nginx NodePort 10.96.97.250 <none> 8081:31819/TCP 30h
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/my-nginx 3/3 3 3 2d20h
NAME DESIRED CURRENT READY AGE
replicaset.apps/my-nginx-697c5bb596 0 0 0 7h47m
replicaset.apps/my-nginx-6b74b79f57 3 3 3 2d20h
replicaset.apps/my-nginx-f56756f49 0 0 0 7h39m
[root@k8s-01 ~]# kubectl delete deployment.apps/my-nginx
deployment.apps "my-nginx" deleted
[root@k8s-01 ~]# kubectl delete service/my-nginx
service "my-nginx" deleted
[root@k8s-01 ~]# kubectl get all
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 4d8h
[root@k8s-01 ~]# kubectl apply -f deploy.yaml
deployment.apps/nginx-deployment created
[root@k8s-01 ~]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/nginx-deployment-746fbb99df-z8tnb 1/1 Running 0 50s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 4d8h
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-deployment 1/1 1 1 51s
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-deployment-746fbb99df 1 1 1 51s
修改deploy.yaml副本數(shù)=3
[root@k8s-01 ~]# kubectl apply -f deploy.yaml
deployment.apps/nginx-deployment configured
[root@k8s-01 ~]# kubectl get deploy,pod
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-deployment 2/3 3 2 12m
NAME READY STATUS RESTARTS AGE
pod/nginx-deployment-746fbb99df-bcbkb 1/1 Running 0 24s
pod/nginx-deployment-746fbb99df-r9p6t 1/1 Running 0 24s
pod/nginx-deployment-746fbb99df-z8tnb 1/1 Running 0 12m
刪除副本數(shù)
[root@k8s-01 ~]# kubectl delete -f deploy.yaml
deployment.apps "nginx-deployment" deleted
[root@k8s-01 ~]# kubectl get deploy,pod
No resources found in default namespace.
k8s部署DashBoard
1.部署Dashboard UI
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