K8S v1.18.x 部署-Kubeadm方式-9:部署Addon-Nginx Ingress
作者:互联网
Ingress
Kubernetes中,Service资源和Pod资源的IP地址仅能用于集群网络内部的通信,所有的网络流量都无法穿透边界路由器(Edge Router)以实现集群内外通信。尽管可以为Service使用NodePort或LoadBalancer类型通过节点引入外部流量,但它依然是4 层流量转发,可用的负载均衡器也为传输层负载均衡机制。
Ingress是Kubernetes API的标准资源类型之一,它其实就是一组基于DNS名称(host)或URL路径把请求转发至指定的Service 资源的规则,用于将集群外部的请求流量转发至集群内部完成服务发布。然而,Ingress资源自身并不能进行“流量穿透”,它仅是 一组路由规则的集合,这些规则要想真正发挥作用还需要其他功能的辅助,如监听某套接字,然后根据这些规则的匹配机制路由请求 流量。这种能够为Ingress资源监听套接字并转发流量的组件称为Ingress控制器(Ingress Controller)。
说明:图片来源于网络。
Ingress控制器可以由任何具有反向代理(HTTP/HTTPS)功能的服务程序实现,如Nginx、Envoy、HAProxy、Vulcand和Traefik等。Ingress控制器自身也是运行于集群中的Pod资源对象,它与被代理的运行为Pod资源的应用运行于同一网络中,如上图中ingress-nginx 与pod1、pod3等的关系所示。
另一方面,使用Ingress资源进行流量分发时,Ingress控制器可基于某Ingress资源定义的规则将客户端的请求流量直接转发至与Service对应 的后端Pod资源之上,这种转发机制会绕过Service资源,从而省去了由kube-proxy实现的端口代理开销。如上图所示,Ingress规则需要由一个 Service资源对象辅助识别相关的所有Pod对象,但ingress-nginx控制器可经由site2.ikubernetes.io规则的定义直接将请求流量调度至pod3 或pod4,而无须经由Service对象API的再次转发。
部署准备
获取部署文件
[root@K8S-PROD-M1 ingress]# wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/ingress-nginx-3.1.0/deploy/static/provider/baremetal/deploy.yaml ingress-nginx-3.1.0.yaml
获取部署镜像
根据YAML中的镜像版本,提前下载镜像:
docker pull vicren/ingress-nginx-controller:v0.35.0
docker tag vicren/ingress-nginx-controller:v0.35.0 harbor.cluster.local/library/ingress-nginx-controller:v0.35.0
docker push harbor.cluster.local/library/ingress-nginx-controller:v0.35.0
docker rmi vicren/ingress-nginx-controller:v0.35.0
修改部署文件
针对Service增加NodePort:
...
spec:
type: NodePort
ports:
- name: http
port: 80
protocol: TCP
targetPort: http
nodePort: 30080 #指定NodePort端口 - name: https
port: 443
protocol: TCP
targetPort: https
nodePort: 30443 #指定NodePort端口
...
修改Deployment中部分配置:
...
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
helm.sh/chart: ingress-nginx-3.0.0
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/version: 0.35.0
app.kubernetes.io/managed-by: Helm
app.kubernetes.io/component: controller
name: ingress-nginx-controller
namespace: ingress-nginx
spec:
replicas: 3 #设置副本数
selector:
matchLabels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/component: controller
revisionHistoryLimit: 10
minReadySeconds: 0
template:
metadata:
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/component: controller
spec:
dnsPolicy: ClusterFirst
containers:
- name: controller
image: harbor.cluster.local/library/ingress-nginx-controller:v0.35.0 #更新镜像地址
imagePullPolicy: IfNotPresent
lifecycle:
preStop:
exec:
command:- /wait-shutdown
args:- /nginx-ingress-controller
- --election-id=ingress-controller-leader
- --ingress-class=nginx
- --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
- --validating-webhook=:8443
- --validating-webhook-certificate=/usr/local/certificates/cert
- --validating-webhook-key=/usr/local/certificates/key
- --default-backend-service=$(POD_NAMESPACE)/default-http-backend #配置Default Backend后,需要部署default backend,否则ingress-nginx-controller运行将进入CrashLoopBackOff状态
...
执行部署
部署命令
kubectl apply -f ingress-nginx-3.1.0.yaml
访问Nginx
在ingress-nginx-controller正常运行以后,K8S每个节点上均监听30080和30443端口,访问Nginx WebUI:
- /wait-shutdown
获得404 Not Found异常。
可根据后面测试部分配置的NAT转发规则进行本地浏览器访问。
部署default backend
创建部署文件
apiVersion: apps/v1
kind: Deployment
metadata:
name: default-http-backend
labels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
namespace: ingress-nginx
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
template:
metadata:
labels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
spec:
terminationGracePeriodSeconds: 60
containers:
- name: default-http-backend
Any image is permissible as long as:
# 1. It serves a 404 page at / # 2. It serves 200 on a /healthz endpoint image: harbor.cluster.local/library/defaultbackend-amd64:1.5 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
namespace: ingress-nginx
labels:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
spec:
ports:- port: 80
targetPort: 8080
selector:
app.kubernetes.io/name: default-http-backend
app.kubernetes.io/part-of: ingress-nginx
执行部署
[root@K8S-PROD-M1 ingress]# kubectl apply -f default-backend.yml
测试 - NAT配置
- port: 80
iptables -t nat -A PREROUTING -m tcp -p tcp -d 192.168.191.32 --dport 30080 -j DNAT --to-destination 192.168.122.12:30080
iptables -t nat -A PREROUTING -m tcp -p tcp -d 192.168.191.32 --dport 30443 -j DNAT --to-destination 192.168.122.12:30443
- 访问Web UI
获得default backend - 404。
测试Ingress
创建Tomcat测试页面
echo '<h1>Hello World!</h1>' > index.html
scp index.html root@K8S-PROD-W1:/tmp/
scp index.html root@K8S-PROD-W2:/tmp/
scp index.html root@K8S-PROD-W3:/tmp/
创建第一个SVC和POD
apiVersion: v1
kind: Service
metadata:
name: svc-demo-1
namespace: default
spec:
selector:
app: pod-demo-1
ports:
-
name: http
port: 80
targetPort: 80apiVersion: apps/v1
kind: Deployment
metadata:
name: deploy-demo-1
namespace: default
spec:
replicas: 3
selector:
matchLabels:
app: pod-demo-1
template:
metadata:
labels:
app: pod-demo-1
spec:
containers:- name: myapp
image: harbor.cluster.local/library/myapp:v2
ports:- name: httpd
containerPort: 80
[root@K8S-PROD-M1 ingress]# kubectl apply -f deploy-demo-1.yaml
创建第二个SVC和POD
apiVersion: v1
kind: Service
metadata:
name: svc-demo-2
namespace: default
spec:
selector:
app: pod-demo-2
ports:
- name: httpd
- name: myapp
- name: httpd
port: 8080
targetPort: 8080
apiVersion: apps/v1
kind: Deployment
metadata:
name: deploy-demo-2
namespace: default
spec:
replicas: 3
selector:
matchLabels:
app: pod-demo-2
template:
metadata:
labels:
app: pod-demo-2
spec:
containers:
- name: mytomcat
image: harbor.cluster.local/library/tomcat:9
ports:- name: httpd
containerPort: 8080
volumeMounts: - mountPath: "/usr/local/tomcat/webapps/ROOT/index.html"
name: tomacat-volume
readOnly: true
volumes:
- name: httpd
- name: tomacat-volume
hostPath:
type: File
path: /tmp/index.html
[root@K8S-PROD-M1 ingress]# kubectl apply -f deploy-demo-2.yaml
创建Ingress
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: ingress-demo
namespace: default
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
rules:- host: demo01.cluster.local
http:
paths:
- host: demo01.cluster.local
- path:
backend:
serviceName: svc-demo-1
servicePort: 80- host: demo02.cluster.local
http:
paths:
- host: demo02.cluster.local
- path:
backend:
serviceName: svc-demo-2
servicePort: 8080创建
[root@K8S-PROD-M1 ingress]# kubectl apply -f ingress-demo.yaml
查看
[root@K8S-PROD-M1 ~]# kubectl get ingress
NAME CLASS HOSTS ADDRESS PORTS AGE
ingress-demo <none> demo01.cluster.local,demo02.cluster.local 192.168.122.22 80 14m
测试验证
- 配置域名解析
测试主机中添加针对demo01.cluster.local,demo02.cluster.local的域名解析:
[root@server ~]# vi /etc/hosts
...
192.168.122.22 demo01.cluster.local
192.168.122.22 demo02.cluster.local
- curl测试
[root@depot ~]# curl http://demo02.cluster.local:30080/
<h1>Hello World!</h1>
[root@depot ~]# curl http://demo02.cluster.local:30080/
<h1>Hello World!</h1>
- Web UI测试
测试Ingess访问(Ingress Nginx Controller以NodePort:30080的方式暴露):http://demo01.cluster.local:30080/。
Ingesss启用TLS
准备自签证书
[root@K8S-PROD-M1 ingress]# openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout demo01.key -out demo01.crt -subj "/CN=demo01.cluster.local"
Generating a 2048 bit RSA private key
...................+++
...................................+++
writing new private key to 'demo01.key'
创建Secret资源
[root@K8S-PROD-M1 ingress]# kubectl create secret generic ingress-demo01-tls --from-file=demo01.crt --from-file=demo01.key -n default
secret/ingress-demo01-tls created
创建TLS Ingress
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: ingress-tls-demo
namespace: default
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
tls:
- hosts:
- demo01.cluster.local
secretName: ingress-demo01-tls
rules:
- demo01.cluster.local
- host: demo03.cluster.local
http:
paths:- path:
backend:
serviceName: svc-demo-1
servicePort: 80
[root@K8S-PROD-M1 ingress]# kubectl apply -f ingress-tls-demo.yaml
测试验证
查看ingress:
- path:
[root@K8S-PROD-M1 ~]# kubectl get ingress
NAME CLASS HOSTS ADDRESS PORTS AGE
ingress-demo <none> demo01.cluster.local,demo02.cluster.local 192.168.122.22 80 27h
ingress-tls-demo <none> demo03.cluster.local 192.168.122.22 80, 443 7m15s
测试主机中添加针对demo03.cluster.local的域名解析:
[root@server ~]# vi /etc/hosts
...
192.168.122.22 demo03.cluster.local
测试Ingess访问(Ingress Nginx Controller以NodePort:30443的方式暴露):https://demo01.cluster.local:30443/。
标签:v1.18,Ingress,name,kubernetes,部署,ingress,cluster,io,local 来源: https://blog.51cto.com/15127525/2658812