k8s中的微服务

一、什么是微服务

用控制器来完成集群的工作负载，那么应用如何暴漏出去？需要通过微服务暴漏出去后才能被访问

Service是一组提供相同服务的Pod对外开放的接口。
借助Service，应用可以实现服务发现和负载均衡。
service默认只支持4层负载均衡能力，没有7层功能。（可以通过Ingress实现）

二微服务的类型

微服务类型	作用描述
ClusterIP	默认值，k8s系统给service自动分配的虚拟IP，只能在集群内部访问
NodePort	将Service通过指定的Node上的端口暴露给外部，访问任意一个NodeIP:nodePort都将路由到ClusterIP
LoadBalancer	在NodePort的基础上,借助cloud provider创建一个外部的负载均衡器，并将请求转发到 NodeIP:NodePort，此模式只能在云服务器上使用
ExternalName	将服务通过 DNS CNAME 记录方式转发到指定的域名（通过 spec.externlName 设定

示例：

生成控制器文件并建立控制器

kubectl create deployment timinglee --image myapp:v1  --replicas 2 --dry-run=client -o yaml > timinglee.yaml

生成微服务yaml追加到已有yaml中

kubectl expose deployment timinglee --port 80 --target-port 80 --dry-run=client -o yaml >> timinglee.yaml


[root@k8s-master ~]# vim timinglee.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: timinglee
  name: timinglee
spec:
  replicas: 2
  selector:
    matchLabels:
      app: timinglee
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: timinglee
    spec:
      containers:
      - image: myapp:v1
        name: myapp
---                                     #不同资源间用---隔开

apiVersion: v1
kind: Service
metadata:
  labels:
    app: timinglee
  name: timinglee
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: timinglee


[root@k8s-master ~]# kubectl apply  -f timinglee.yaml
deployment.apps/timinglee created
service/timinglee created

[root@k8s-master ~]# kubectl get services
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP   19h
timinglee    ClusterIP   10.99.127.134   <none>        80/TCP    16s

微服务默认使用iptables调度

[root@k8s-master ~]# kubectl get services  -o wide
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE    SELECTOR
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP   19h    <none>
timinglee    ClusterIP   10.99.127.134   <none>        80/TCP    119s   app=timinglee           #集群内部IP 134

#可以在火墙中查看到策略信息
[root@k8s-master ~]# iptables -t nat -nL
KUBE-SVC-I7WXYK76FWYNTTGM  6    --  0.0.0.0/0            10.99.127.134        /* default/timinglee cluster IP */ tcp dpt:80

三 ipvs模式

Service 是由 kube-proxy 组件，加上 iptables 来共同实现的
kube-proxy 通过 iptables 处理 Service 的过程，需要在宿主机上设置相当多的 iptables 规则，如果宿主机有大量的Pod，不断刷新iptables规则，会消耗大量的CPU资源
IPVS模式的service，可以使K8s集群支持更多量级的Pod

3.1 ipvs模式配置方式

1 在所有节点中安装ipvsadm

[root@k8s-所有节点 pod]yum install ipvsadm –y

2 修改master节点的代理配置

[root@k8s-master ~]# kubectl -n kube-system edit cm kube-proxy
    metricsBindAddress: ""
    mode: "ipvs"                            #设置kube-proxy使用ipvs模式
    nftables:

3 重启pod，在pod运行时配置文件中采用默认配置，当改变配置文件后已经运行的pod状态不会变化，所以要重启pod

[root@k8s-master ~]# kubectl -n kube-system get  pods   | awk '/kube-proxy/{system("kubectl -n kube-system delete pods "$1)}'

[root@k8s-master ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.96.0.1:443 rr
  -> 172.25.254.100:6443          Masq    1      0          0
TCP  10.96.0.10:53 rr
  -> 10.244.0.2:53                Masq    1      0          0
  -> 10.244.0.3:53                Masq    1      0          0
TCP  10.96.0.10:9153 rr
  -> 10.244.0.2:9153              Masq    1      0          0
  -> 10.244.0.3:9153              Masq    1      0          0
TCP  10.97.59.25:80 rr
  -> 10.244.1.17:80               Masq    1      0          0
  -> 10.244.2.13:80               Masq    1      0          0
UDP  10.96.0.10:53 rr
  -> 10.244.0.2:53                Masq    1      0          0
  -> 10.244.0.3:53                Masq    1      0          0

[!NOTE]

切换ipvs模式后，kube-proxy会在宿主机上添加一个虚拟网卡：kube-ipvs0，并分配所有service IP

[root@k8s-master ~]# ip a | tail
 inet6 fe80::c4fb:e9ff:feee:7d32/64 scope link
    valid_lft forever preferred_lft forever
8: kube-ipvs0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default
 link/ether fe:9f:c8:5d:a6:c8 brd ff:ff:ff:ff:ff:ff
 inet 10.96.0.10/32 scope global kube-ipvs0
    valid_lft forever preferred_lft forever
 inet 10.96.0.1/32 scope global kube-ipvs0
    valid_lft forever preferred_lft forever
 inet 10.97.59.25/32 scope global kube-ipvs0
    valid_lft forever preferred_lft forever

四微服务类型详解

4.1 clusterip

特点：

clusterip模式只能在集群内访问，并对集群内的pod提供健康检测和自动发现功能

示例：

[root@k8s2 service]# vim myapp.yml
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: timinglee
  name: timinglee
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: timinglee
  type: ClusterIP


service创建后集群DNS提供解析
[root@k8s-master ~]# dig  timinglee.default.svc.cluster.local @10.96.0.10

; <<>> DiG 9.16.23-RH <<>> timinglee.default.svc.cluster.local @10.96.0.10
;; global options: +cmd
;; Got answer:
;; WARNING: .local is reserved for Multicast DNS
;; You are currently testing what happens when an mDNS query is leaked to DNS
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27827
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 057d9ff344fe9a3a (echoed)
;; QUESTION SECTION:
;timinglee.default.svc.cluster.local. IN        A

;; ANSWER SECTION:
timinglee.default.svc.cluster.local. 30 IN A    10.97.59.25

;; Query time: 8 msec
;; SERVER: 10.96.0.10#53(10.96.0.10)
;; WHEN: Wed Sep 04 13:44:30 CST 2024
;; MSG SIZE  rcvd: 127

4.2 ClusterIP中的特殊模式headless

headless（无头服务）

对于无头 Services 并不会分配 Cluster IP，kube-proxy不会处理它们，而且平台也不会为它们进行负载均衡和路由，集群访问通过dns解析直接指向到业务pod上的IP，所有的调度有dns单独完成

[root@k8s-master ~]# vim timinglee.yaml
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: timinglee
  name: timinglee
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: timinglee
  type: ClusterIP
  clusterIP: None


[root@k8s-master ~]# kubectl delete -f timinglee.yaml
[root@k8s-master ~]# kubectl apply -f timinglee.yaml
deployment.apps/timinglee created

#测试
[root@k8s-master ~]# kubectl get services timinglee
NAME        TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
timinglee   ClusterIP   None         <none>        80/TCP    6s

[root@k8s-master ~]# dig  timinglee.default.svc.cluster.local @10.96.0.10

; <<>> DiG 9.16.23-RH <<>> timinglee.default.svc.cluster.local @10.96.0.10
;; global options: +cmd
;; Got answer:
;; WARNING: .local is reserved for Multicast DNS
;; You are currently testing what happens when an mDNS query is leaked to DNS
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51527
;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 81f9c97b3f28b3b9 (echoed)
;; QUESTION SECTION:
;timinglee.default.svc.cluster.local. IN        A

;; ANSWER SECTION:
timinglee.default.svc.cluster.local. 20 IN A    10.244.2.14     #直接解析到pod上
timinglee.default.svc.cluster.local. 20 IN A    10.244.1.18

;; Query time: 0 msec
;; SERVER: 10.96.0.10#53(10.96.0.10)
;; WHEN: Wed Sep 04 13:58:23 CST 2024
;; MSG SIZE  rcvd: 178


#开启一个busyboxplus的pod测试
[root@k8s-master ~]# kubectl run  test --image busyboxplus -it
If you don't see a command prompt, try pressing enter.
/ # nslookup timinglee-service
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      timinglee-service
Address 1: 10.244.2.16 10-244-2-16.timinglee-service.default.svc.cluster.local
Address 2: 10.244.2.17 10-244-2-17.timinglee-service.default.svc.cluster.local
Address 3: 10.244.1.22 10-244-1-22.timinglee-service.default.svc.cluster.local
Address 4: 10.244.1.21 10-244-1-21.timinglee-service.default.svc.cluster.local
/ # curl timinglee-service
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
/ # curl timinglee-service/hostname.html
timinglee-c56f584cf-b8t6m

4.3 nodeport

通过ipvs暴漏端口从而使外部主机通过master节点的对外ip:<port>来访问pod业务

其访问过程为：

示例：

[root@k8s-master ~]# vim timinglee.yaml

---

apiVersion: v1
kind: Service
metadata:
  labels:
    app: timinglee-service
  name: timinglee-service
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: timinglee
  type: NodePort


[root@k8s-master ~]# kubectl apply -f timinglee.yaml
deployment.apps/timinglee created
service/timinglee-service created
[root@k8s-master ~]# kubectl get services  timinglee-service
NAME                TYPE       CLUSTER-IP    EXTERNAL-IP   PORT(S)        AGE
timinglee-service   NodePort   10.98.60.22   <none>        80:31771/TCP   8

nodeport在集群节点上绑定端口，一个端口对应一个服务
[root@k8s-master ~]# for i in {1..5}
> do
> curl 172.25.254.100:31771/hostname.html
> done
timinglee-c56f584cf-fjxdk
timinglee-c56f584cf-5m2z5
timinglee-c56f584cf-z2w4d
timinglee-c56f584cf-tt5g6
timinglee-c56f584cf-fjxdk

[!NOTE]

nodeport默认端口

nodeport默认端口是30000-32767，超出会报错

[root@k8s-master ~]# vim timinglee.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    app: timinglee-service
  name: timinglee-service
spec:
  ports:

  - port: 80
    protocol: TCP
    targetPort: 80
    nodePort: 33333
      selector:
    app: timinglee
      type: NodePort

[root@k8s-master ~]# kubectl apply -f timinglee.yaml
deployment.apps/timinglee created
The Service "timinglee-service" is invalid: spec.ports[0].nodePort: Invalid value: 33333: provided port is not in the valid range. The range of valid ports is 30000-32767

如果需要使用这个范围以外的端口就需要特殊设定

[root@k8s-master ~]# vim /etc/kubernetes/manifests/kube-apiserver.yaml

- --service-node-port-range=30000-40000

[!NOTE]

添加“--service-node-port-range=“ 参数，端口范围可以自定义

修改后api-server会自动重启，等apiserver正常启动后才能操作集群

集群重启自动完成在修改完参数后全程不需要人为干预

4.4 loadbalancer

云平台会为我们分配vip并实现访问，如果是裸金属主机那么需要metallb来实现ip的分配

[root@k8s-master ~]# vim timinglee.yaml

---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: timinglee-service
  name: timinglee-service
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: timinglee
  type: LoadBalancer


[root@k8s2 service]# kubectl apply -f myapp.yml

默认无法分配外部访问IP
[root@k8s2 service]# kubectl get svc
NAME         TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP      10.96.0.1       <none>        443/TCP        4d1h
myapp        LoadBalancer   10.107.23.134   <pending>     80:32537/TCP   4s

LoadBalancer模式适用云平台，裸金属环境需要安装metallb提供支持

4.5 metalLB

官网：Installation :: MetalLB, bare metal load-balancer for Kubernetes

metalLB功能

为LoadBalancer分配vip

部署方式

1.设置ipvs模式
[root@k8s-master ~]# kubectl edit cm -n kube-system kube-proxy
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: "ipvs"
ipvs:
  strictARP: true

[root@k8s-master ~]# kubectl -n kube-system get  pods   | awk '/kube-proxy/{system("kubectl -n kube-system delete pods "$1)}'

2.下载部署文件
[root@k8s2 metallb]# wget https://raw.githubusercontent.com/metallb/metallb/v0.13.12/config/manifests/metallb-native.yaml

3.修改文件中镜像地址,与harbor仓库路径保持一致
[root@k8s-master ~]# vim metallb-native.yaml
...
image: metallb/controller:v0.14.8
image: metallb/speaker:v0.14.8

4.上传镜像到harbor
[root@k8s-master ~]# docker pull quay.io/metallb/controller:v0.14.8
[root@k8s-master ~]# docker pull quay.io/metallb/speaker:v0.14.8

[root@k8s-master ~]# docker tag quay.io/metallb/speaker:v0.14.8 reg.timinglee.org/metallb/speaker:v0.14.8
[root@k8s-master ~]# docker tag quay.io/metallb/controller:v0.14.8 reg.timinglee.org/metallb/controller:v0.14.8

[root@k8s-master ~]# docker push reg.timinglee.org/metallb/speaker:v0.14.8
[root@k8s-master ~]# docker push reg.timinglee.org/metallb/controller:v0.14.8


部署服务
[root@k8s2 metallb]# kubectl apply -f metallb-native.yaml
[root@k8s-master ~]# kubectl -n metallb-system get pods
NAME                          READY   STATUS    RESTARTS   AGE
controller-65957f77c8-25nrw   1/1     Running   0          30s
speaker-p94xq                 1/1     Running   0          29s
speaker-qmpct                 1/1     Running   0          29s
speaker-xh4zh                 1/1     Running   0          30s

配置分配地址段
[root@k8s-master ~]# vim configmap.yml
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: first-pool                      #地址池名称
  namespace: metallb-system
spec:
  addresses:
  - 172.25.254.50-172.25.254.99         #修改为自己本地地址段

---                                     #两个不同的kind中间必须加分割
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: example
  namespace: metallb-system
spec:
  ipAddressPools:
  - first-pool                          #使用地址池 

[root@k8s-master ~]# kubectl apply -f configmap.yml
ipaddresspool.metallb.io/first-pool created
l2advertisement.metallb.io/example created


[root@k8s-master ~]# kubectl get services
NAME                TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)        AGE
kubernetes          ClusterIP      10.96.0.1       <none>          443/TCP        21h
timinglee-service   LoadBalancer   10.109.36.123   172.25.254.50   80:31595/TCP   9m9s


#通过分配地址从集群外访问服务
[root@reg ~]# curl  172.25.254.50
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>

4.6 externalname

开启services后，不会被分配IP，而是用dns解析CNAME固定域名来解决ip变化问题
一般应用于外部业务和pod沟通或外部业务迁移到pod内时
在应用向集群迁移过程中，externalname在过度阶段就可以起作用了。
集群外的资源迁移到集群时，在迁移的过程中ip可能会变化，但是域名+dns解析能完美解决此问题

示例：

[root@k8s-master ~]# vim timinglee.yaml

---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: timinglee-service
  name: timinglee-service
spec:
  selector:
    app: timinglee
  type: ExternalName
  externalName: www.timinglee.org

[root@k8s-master ~]# kubectl apply -f timinglee.yaml

[root@k8s-master ~]# kubectl get services  timinglee-service
NAME                TYPE           CLUSTER-IP   EXTERNAL-IP         PORT(S)   AGE
timinglee-service   ExternalName   <none>       www.timinglee.org   <none>    2m58s

五 Ingress-nginx

官网：

Installation Guide - Ingress-Nginx Controller

5.1 ingress-nginx功能

一种全局的、为了代理不同后端 Service 而设置的负载均衡服务,支持7层
Ingress由两部分组成：Ingress controller和Ingress服务
Ingress Controller 会根据你定义的 Ingress 对象，提供对应的代理能力。
业界常用的各种反向代理项目，比如 Nginx、HAProxy、Envoy、Traefik 等，都已经为Kubernetes 专门维护了对应的 Ingress Controller。

5.2 部署ingress

5.2.1 下载部署文件

[root@k8s-master ~]# wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.11.2/deploy/static/provider/baremetal/deploy.yaml

上传ingress所需镜像到harbor

[root@k8s-master ~]# docker tag registry.k8s.io/ingress-nginx/controller:v1.11.2@sha256:d5f8217feeac4887cb1ed21f27c2674e58be06bd8f5184cacea2a69abaf78dce reg.timinglee.org/ingress-nginx/controller:v1.11.2

[root@k8s-master ~]# docker tag registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.4.3@sha256:a320a50cc91bd15fd2d6fa6de58bd98c1bd64b9a6f926ce23a600d87043455a3 reg.timinglee.org/ingress-nginx/kube-webhook-certgen:v1.4.3

[root@k8s-master ~]# docker push reg.timinglee.org/ingress-nginx/controller:v1.11.2
[root@k8s-master ~]# docker push reg.timinglee.org/ingress-nginx/kube-webhook-certgen:v1.4.3

5.2.2 安装ingress

[root@k8s-master ~]# vim deploy.yaml
445         image: ingress-nginx/controller:v1.11.2
546         image: ingress-nginx/kube-webhook-certgen:v1.4.3
599         image: ingress-nginx/kube-webhook-certgen:v1.4.3

[root@k8s-master ~]# kubectl -n ingress-nginx get pods
NAME                                       READY   STATUS      RESTARTS   AGE
ingress-nginx-admission-create-ggqm6       0/1     Completed   0          82s
ingress-nginx-admission-patch-q4wp2        0/1     Completed   0          82s
ingress-nginx-controller-bb7d8f97c-g2h4p   1/1     Running     0          82s
[root@k8s-master ~]# kubectl -n ingress-nginx get svc
NAME                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE
ingress-nginx-controller             NodePort    10.103.33.148   <none>        80:34512/TCP,443:34727/TCP   108s
ingress-nginx-controller-admission   ClusterIP   10.103.183.64   <none>        443/TCP                      108s


#修改微服务为loadbalancer
[root@k8s-master ~]# kubectl -n ingress-nginx edit svc ingress-nginx-controller
49   type: LoadBalancer

[root@k8s-master ~]# kubectl -n ingress-nginx get services
NAME                                 TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)                      AGE
ingress-nginx-controller             LoadBalancer   10.103.33.148   172.25.254.50   80:34512/TCP,443:34727/TCP   4m43s
ingress-nginx-controller-admission   ClusterIP      10.103.183.64   <none>          443/TCP                      4m43s

[!NOTE]

在ingress-nginx-controller中看到的对外IP就是ingress最终对外开放的ip

5.2.3 测试ingress

#生成yaml文件
[root@k8s-master ~]# kubectl create ingress webcluster --rule '*/=timinglee-svc:80' --dry-run=client -o yaml > timinglee-ingress.yml

[root@k8s-master ~]# vim timinglee-ingress.yml

aapiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: test-ingress
spec:
  ingressClassName: nginx
  rules:
  - http:
      paths:
      - backend:
          service:
            name: timinglee-svc
            port:
              number: 80
        path: /
        pathType: Prefix    
        #Exact（精确匹配），ImplementationSpecific（特定实现），Prefix（前缀匹配），Regular expression（正则表达式匹配）

#建立ingress控制器
[root@k8s-master ~]# kubectl apply -f timinglee-ingress.yml
ingress.networking.k8s.io/webserver created

[root@k8s-master ~]# kubectl get ingress
NAME           CLASS   HOSTS   ADDRESS         PORTS   AGE
test-ingress   nginx   *       172.25.254.10   80      8m30s


[root@reg ~]# for n in {1..5}; do curl 172.25.254.50/hostname.html; done
timinglee-c56f584cf-8jhn6
timinglee-c56f584cf-8cwfm
timinglee-c56f584cf-8jhn6
timinglee-c56f584cf-8cwfm
timinglee-c56f584cf-8jhn6

[!NOTE]

ingress必须和输出的service资源处于同一namespace

5.3 ingress 的高级用法

5.3.1 基于路径的访问

1.建立用于测试的控制器myapp

[root@k8s-master app]# kubectl create deployment myapp-v1 --image myapp:v1 --dry-run=client -o yaml > myapp-v1.yaml

[root@k8s-master app]# kubectl create deployment myapp-v2 --image myapp:v2 --dry-run=client -o yaml > myapp-v2.yaml


[root@k8s-master app]# vim myapp-v1.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp-v1
  name: myapp-v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp-v1
  strategy: {}
  template:
    metadata:
      labels:
        app: myapp-v1
    spec:
      containers:
      - image: myapp:v1
        name: myapp

---

apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp-v1
  name: myapp-v1
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp-v1

[root@k8s-master app]# vim myapp-v2.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp-v2
  name: myapp-v2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp-v2
  template:
    metadata:
      labels:
        app: myapp-v2
    spec:
      containers:
      - image: myapp:v2
        name: myapp
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp-v2
  name: myapp-v2
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp-v2

[root@k8s-master app]# kubectl expose deployment myapp-v1 --port 80 --target-port 80 --dry-run=client -o yaml >> myapp-v1.yaml

[root@k8s-master app]# kubectl expose deployment myapp-v2 --port 80 --target-port 80 --dry-run=client -o yaml >> myapp-v1.yaml


[root@k8s-master app]# kubectl get services
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP   29h
myapp-v1     ClusterIP   10.104.84.65     <none>        80/TCP    13s
myapp-v2     ClusterIP   10.105.246.219   <none>        80/TCP    7s

2.建立ingress的yaml

[root@k8s-master app]# vim ingress1.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /		#访问路径后加任何内容都被定向到/
  name: ingress1
spec:
  ingressClassName: nginx
  rules:
  - host: www.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /v1
        pathType: Prefix

      - backend:
          service:
            name: myapp-v2
            port:
              number: 80
        path: /v2
        pathType: Prefix

#测试：
[root@reg ~]# echo 172.25.254.50 www.timinglee.org >> /etc/hosts

[root@reg ~]# curl  www.timinglee.org/v1
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@reg ~]# curl  www.timinglee.org/v2
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>


#nginx.ingress.kubernetes.io/rewrite-target: / 的功能实现
[root@reg ~]# curl  www.timinglee.org/v2/aaaa
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>

5.3.2 基于域名的访问

#在测试主机中设定解析
[root@reg ~]# vim /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
172.25.254.250 reg.timinglee.org
172.25.254.50 www.timinglee.org myappv1.timinglee.org myappv2.timinglee.org

# 建立基于域名的yml文件
[root@k8s-master app]# vim ingress2.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
  name: ingress2
spec:
  ingressClassName: nginx
  rules:
  - host: myappv1.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /
        pathType: Prefix
  - host: myappv2.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v2
            port:
              number: 80
        path: /
        pathType: Prefix

        
#利用文件建立ingress
[root@k8s-master app]# kubectl apply -f ingress2.yml
ingress.networking.k8s.io/ingress2 created

[root@k8s-master app]# kubectl describe ingress ingress2
Name:             ingress2
Labels:           <none>
Namespace:        default
Address:
Ingress Class:    nginx
Default backend:  <default>
Rules:
  Host                   Path  Backends
  ----                   ----  --------
  myappv1.timinglee.org
                         /   myapp-v1:80 (10.244.2.31:80)
  myappv2.timinglee.org
                         /   myapp-v2:80 (10.244.2.32:80)
Annotations:             nginx.ingress.kubernetes.io/rewrite-target: /
Events:
  Type    Reason  Age   From                      Message
  ----    ------  ----  ----                      -------
  Normal  Sync    21s   nginx-ingress-controller  Scheduled for sync


#在测试主机中测试
[root@reg ~]# curl  www.timinglee.org/v1
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@reg ~]# curl  www.timinglee.org/v2
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>

5.3.3 建立tls加密

#建立证书
[root@k8s-master app]# openssl req -newkey rsa:2048 -nodes -keyout tls.key -x509 -days 365 -subj "/CN=nginxsvc/O=nginxsvc" -out tls.crt

#建立加密资源类型secret
[root@k8s-master app]# kubectl create secret tls  web-tls-secret --key tls.key --cert tls.crt
secret/web-tls-secret created
[root@k8s-master app]# kubectl get secrets
NAME             TYPE                DATA   AGE
web-tls-secret   kubernetes.io/tls   2      6s

[!NOTE]

secret通常在kubernetes中存放敏感数据，他并不是一种加密方式，在后面课程中会有专门讲解

#建立ingress3基于tls认证的yml文件
[root@k8s-master app]# vim ingress3.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
  name: ingress3
spec:
  tls:
  - hosts:
    - myapp-tls.timinglee.org
    secretName: web-tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp-tls.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /
        pathType: Prefix

        
#测试
[root@reg ~]# curl -k https://myapp-tls.timinglee.org
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>

5.3.4 建立auth认证

#建立认证文件
[root@k8s-master app]# dnf install httpd-tools -y
[root@k8s-master app]# htpasswd -cm auth lee
New password:
Re-type new password:
Adding password for user lee
[root@k8s-master app]# cat auth
lee:$apr1$BohBRkkI$hZzRDfpdtNzue98bFgcU10

#建立认证类型资源
[root@k8s-master app]# kubectl create secret generic auth-web --from-file auth
root@k8s-master app]# kubectl describe secrets auth-web
Name:         auth-web
Namespace:    default
Labels:       <none>
Annotations:  <none>

Type:  Opaque

Data
====
auth:  42 bytes

#建立ingress4基于用户认证的yaml文件
[root@k8s-master app]# vim ingress4.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: auth-web
    nginx.ingress.kubernetes.io/auth-realm: "Please input username and password"
  name: ingress4
spec:
  tls:
  - hosts:
    - myapp-tls.timinglee.org
    secretName: web-tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp-tls.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /
        pathType: Prefix

#建立ingress4
[root@k8s-master app]# kubectl apply -f ingress4.yml
ingress.networking.k8s.io/ingress4 created
[root@k8s-master app]# kubectl describe ingress ingress4
Name:             ingress4
Labels:           <none>
Namespace:        default
Address:
Ingress Class:    nginx
Default backend:  <default>
TLS:
  web-tls-secret terminates myapp-tls.timinglee.org
Rules:
  Host                     Path  Backends
  ----                     ----  --------
  myapp-tls.timinglee.org
                           /   myapp-v1:80 (10.244.2.31:80)
Annotations:               nginx.ingress.kubernetes.io/auth-realm: Please input username and password
                           nginx.ingress.kubernetes.io/auth-secret: auth-web
                           nginx.ingress.kubernetes.io/auth-type: basic
Events:
  Type    Reason  Age   From                      Message
  ----    ------  ----  ----                      -------
  Normal  Sync    14s   nginx-ingress-controller  Scheduled for sync


#测试：
[root@reg ~]# curl -k https://myapp-tls.timinglee.org
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@reg ~]# vim /etc/hosts ^C
[root@reg ~]# curl -k https://myapp-tls.timinglee.org
<html>
<head><title>401 Authorization Required</title></head>
<body>
<center><h1>401 Authorization Required</h1></center>
<hr><center>nginx</center>
</body>
</html>

[root@reg ~]# curl -k https://myapp-tls.timinglee.org -ulee:lee
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>

5.3.5 rewrite重定向

#指定默认访问的文件到hostname.html上
[root@k8s-master app]# vim ingress5.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/app-root: /hostname.html
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: auth-web
    nginx.ingress.kubernetes.io/auth-realm: "Please input username and password"
  name: ingress5
spec:
  tls:
  - hosts:
    - myapp-tls.timinglee.org
    secretName: web-tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp-tls.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /
        pathType: Prefix

[root@k8s-master app]# kubectl apply -f ingress5.yml
ingress.networking.k8s.io/ingress5 created
[root@k8s-master app]# kubectl describe ingress ingress5
Name:             ingress5
Labels:           <none>
Namespace:        default
Address:          172.25.254.10
Ingress Class:    nginx
Default backend:  <default>
TLS:
  web-tls-secret terminates myapp-tls.timinglee.org
Rules:
  Host                     Path  Backends
  ----                     ----  --------
  myapp-tls.timinglee.org
                           /   myapp-v1:80 (10.244.2.31:80)
Annotations:               nginx.ingress.kubernetes.io/app-root: /hostname.html
                           nginx.ingress.kubernetes.io/auth-realm: Please input username and password
                           nginx.ingress.kubernetes.io/auth-secret: auth-web
                           nginx.ingress.kubernetes.io/auth-type: basic
Events:
  Type    Reason  Age                    From                      Message
  ----    ------  ----                   ----                      -------
  Normal  Sync    2m16s (x2 over 2m54s)  nginx-ingress-controller  Scheduled for sync

#测试：
[root@reg ~]# curl -Lk https://myapp-tls.timinglee.org -ulee:lee
myapp-v1-7479d6c54d-j9xc6

[root@reg ~]# curl -Lk https://myapp-tls.timinglee.org/lee/hostname.html -ulee:lee
<html>
<head><title>404 Not Found</title></head>
<body bgcolor="white">
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.12.2</center>
</body>
</html>


#解决重定向路径问题

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$2
    nginx.ingress.kubernetes.io/use-regex: "true"
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: auth-web
    nginx.ingress.kubernetes.io/auth-realm: "Please input username and password"
  name: ingress6
spec:
  tls:
  - hosts:
    - myapp-tls.timinglee.org
    secretName: web-tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp-tls.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /
        pathType: Prefix
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /lee(/|$)(.*)					#正则表达式匹配/lee/，/lee/abc
        pathType: ImplementationSpecific

#测试
[root@reg ~]# curl -Lk https://myapp-tls.timinglee.org/lee/hostname.html -ulee:lee
myapp-v1-7479d6c54d-j9xc6

六 Canary金丝雀发布

6.1 么是金丝雀发布

金丝雀发布（Canary Release）也称为灰度发布，是一种软件发布策略。

主要目的是在将新版本的软件全面推广到生产环境之前，先在一小部分用户或服务器上进行测试和验证，以降低因新版本引入重大问题而对整个系统造成的影响。

是一种Pod的发布方式。金丝雀发布采取先添加、再删除的方式，保证Pod的总量不低于期望值。并且在更新部分Pod后，暂停更新，当确认新Pod版本运行正常后再进行其他版本的Pod的更新。

6.2 Canary发布方式

其中header和weiht中的最多

6.2.1 基于header（http包头）灰度

通过Annotaion扩展
创建灰度ingress，配置灰度头部key以及value
灰度流量验证完毕后，切换正式ingress到新版本
之前我们在做升级时可以通过控制器做滚动更新，默认25%利用header可以使升级更为平滑，通过key 和vule 测试新的业务体系是否有问题。

示例：

#建立版本1的ingress
[root@k8s-master app]# vim ingress7.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
  name: myapp-v1-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v1
            port:
              number: 80
        path: /
        pathType: Prefix

        
[root@k8s-master app]# kubectl describe ingress myapp-v1-ingress
Name:             myapp-v1-ingress
Labels:           <none>
Namespace:        default
Address:          172.25.254.10
Ingress Class:    nginx
Default backend:  <default>
Rules:
  Host                 Path  Backends
  ----                 ----  --------
  myapp.timinglee.org
                       /   myapp-v1:80 (10.244.2.31:80)
Annotations:           <none>
Events:
  Type    Reason  Age                From                      Message
  ----    ------  ----               ----                      -------
  Normal  Sync    44s (x2 over 73s)  nginx-ingress-controller  Scheduled for sync


#建立基于header的ingress
[root@k8s-master app]# vim ingress8.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-by-header: version
    nginx.ingress.kubernetes.io/canary-by-header-value: 2
  name: myapp-v2-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v2
            port:
              number: 80
        path: /
        pathType: Prefix

[root@k8s-master app]# kubectl apply -f ingress8.yml
ingress.networking.k8s.io/myapp-v2-ingress created
[root@k8s-master app]# kubectl describe ingress myapp-v2-ingress
Name:             myapp-v2-ingress
Labels:           <none>
Namespace:        default
Address:
Ingress Class:    nginx
Default backend:  <default>
Rules:
  Host                 Path  Backends
  ----                 ----  --------
  myapp.timinglee.org
                       /   myapp-v2:80 (10.244.2.32:80)
Annotations:           nginx.ingress.kubernetes.io/canary: true
                       nginx.ingress.kubernetes.io/canary-by-header: version
                       nginx.ingress.kubernetes.io/canary-by-header-value: 2
Events:
  Type    Reason  Age   From                      Message
  ----    ------  ----  ----                      -------
  Normal  Sync    21s   nginx-ingress-controller  Scheduled for sync

#测试：
[root@reg ~]# curl  myapp.timinglee.org
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@reg ~]# curl -H "version: 2" myapp.timinglee.org
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>

6.2.2 基于权重的灰度发布

通过Annotaion拓展
创建灰度ingress，配置灰度权重以及总权重
灰度流量验证完毕后，切换正式ingress到新版本

示例

#基于权重的灰度发布
[root@k8s-master app]# vim ingress8.yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "10"		#更改权重值
    nginx.ingress.kubernetes.io/canary-weight-total: "100"
  name: myapp-v2-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.timinglee.org
    http:
      paths:
      - backend:
          service:
            name: myapp-v2
            port:
              number: 80
        path: /
        pathType: Prefix

[root@k8s-master app]# kubectl apply -f ingress8.yml
ingress.networking.k8s.io/myapp-v2-ingress created

#测试：
[root@reg ~]# vim check_ingress.sh

#!/bin/bash
v1=0
v2=0

for (( i=0; i<100; i++))
do
    response=`curl -s myapp.timinglee.org |grep -c v1`

    v1=`expr $v1 + $response`
    v2=`expr $v2 + 1 - $response`

done
echo "v1:$v1, v2:$v2"

[root@reg ~]# sh check_ingress.sh
v1:90, v2:10

#更改完毕权重后继续测试可观察变化